Flores hominins: Liang Bua and Mata Menge

 

Executive Summary

1. It is not surprising that Mata Menge yielded some hominin remains. Artefacts found there earlier for many years indicated hominin occupation.

2. Hominin fragments now described are undiagnostic taxonomically beyond saying that they are from a hominin. Small jaw/tooth size falls within the range of Pleistocene hominins.

3. They may be ancestors of any hominin living later on Flores, no specific link to just a putative species H. floresiensis can be made

4. These new finds do not change our interpretation of the hominin bone assemblage from Liang Bua site – a fragmentary sample of small bodied H.sapiens with one pathological individual.

This file records our research group’s preliminary responses to copies of two papers now in press at Nature:

  • Brumm A, et al. (in press 2016) Age and context of the oldest known hominin fossils from Flores. Nature: doi:10.1038/nature17663
  • van den Berg, G. (in press 2016) Homo floresiensis-like fossils from the early Middle Pleistocene of Flores. Nature: doi:10.1038/nature 17999

Background

The specimens reported in the above-cited papers were excavated in 2014, so the investigators have had access to them for approximately two years. We received embargoed copies of the papers four days ago, on June 3, 2016, so have had only a few days to review the material intended for publication.

We are pleased to learn of the additional artefacts and human gnathic remains from Mata Menge (MM). Beginning a decade ago (Jacob et al., 2006) our group has referenced this site repeatedly, noting the early date of material from it, and its importance in treating many matters concerning human evolution among Australomelanesian populations. The First Mariners by Robert Bednarik (the scholar who suggested to Mike Morwood that Flores presented promising sites for the study of human ancestry in this region) provides a broadly informative context for understanding the ancient webs of contact and dispersion among continental, island, and ocean populations going back through the time range that includes Homo erectus, s.l. populations in the broad sense, and their phyletically successive species, Homo sapiens.

In assessing the diagnostic meaning of the recently discovered Mata Menge specimens it is useful to begin with a key sentence in the abstract of the 2004 paper in Nature (Brown, et al., 2004) that first proposed the existence of the taxon referred to as “Homo floresiensis”:

Here we report the discovery, from the late Pleistocene of Flores, Indonesia, of an adult hominin with stature and endocranial volume approximating 1 m and 380 cm3, respectively.”

Our group’s research, published in 2006 and subsequently, has shown that both of the above values are substantial underestimates. The best current value for the endocranial volume of LB1 (the only known skull attributed to “Homo floresiensis” from the Liang Bua site or any other) is 430 ml (cm3). More appropriate stature estimates for LB1 (the only individual for which femurs are known) are approximately 1.25 to 1.30 m, which overlap the statures of some living Homo sapiens on Flores and elsewhere. Our estimates of endocranial volume and stature have been confirmed independently.

The formal diagnosistic elements of the proposed species “Homo floresiensis” from Liang Bua (LB) are listed here (in left column) in order originally presented).

Right column notes assess whether the LB1 (and LB2) characteristics can be observed in the Mata Menge material now in press (van den Bergh, et al. 2016).

 

Morphological characteristics listed in Brown, et al., 2004 (based on LB1 partial skeleton and LB2 isolated left P3 Mata Menge gnathic remains
Mandible SOA-MM4
Left I1, right P3, I1/2, left M1/2
Deciduous teeth (l and r dc)
small-bodied hominin yes
bipedal unobservable (but see “Note” below)
stature (body height) similar to, or smaller than, Australopithecus africanus unobservable
endocranial volume similar to, or smaller than, Australopithecus africanus unobservable
lacks masticatory adaptations present in Australopithecus and Paranthropus probable
substantially reduced facial height and prognathism unobservable
smaller postcanine teeth probable
posteriorly oriented infraorbital region unobservable
cranial base flexed unobservable
prominent maxillary canine juga form prominent pillars, laterally separated from nasal aperture unobservable
petrous pyramid smooth and with low relief unobservable
styloid process absent unobservable
without vaginal crest unobservable
superior cranial vault bone thicker than Australopithecus and similar to H. sapiens unobservable
supraorbital torus arches over each orbit and does not form a flat bar as in Javan H. erectus unobservable
mandibular P3 with relatively large occlusal surface area, with prominent protoconid and broad talonid unobservable
mandibular P3 with either bifurcated roots or a mesiodistally compressed Tomes’ root unobservable
mandibular P4 also with Tomes root yes, bifurcated root
(but a polymorphic trait)
first and second molar teeth of similar size unobservable
mandibular coronoid process higher than condyle unobservable
ramus [of mandible] has a posterior orientation unobservable
mandible without chin unobservable
posterior inclination of [mandibular] symphysial axis unobservable
posteriorly inclined alveolar planum with superior and inferior transverse tori unobservable
ilium with marked lateral flare unobservable
femur neck long relative to head diameter unobservable
femur shaft circular and without pilaster unobservable
high bicondylar angle unobservable
long axis of tibia curved and the midshaft has an oval cross-section unobservable

 

Note: LB1 specimen attributed to “H. floresiensis” was reconstructed as quadrupedal by G. van den Bergh (2005) in Natuurwetenschap & Techniek. We are unaware of any subsequent changes published by Dr. van den Bergh of his earlier views but they are assuredly incorrect for LB1 (which undoubtedly was bipedal) and, by any reasonable scientific inference, to the fossils sampled from the Mata Menge hominin population.

Brief Comments:

From the above preliminary comparisons it should be noted that the overlaps of the Mata Menge gnathic remains with those reported from Liang Bua are minimal. The most pertinent Liang Bua elements are the LB1 and LB6 mandibles, plus several isolated teeth. Sizes of Mata Menge teeth and the mandibular fragments are comparable (within ranges of individual variation) with various Pleistocene hominins. The molar crown SOA-MM1, that is small even in comparison to LB teeth, may be that of the second deciduous molar because its wear is slight. It shows proximal wear on the distal surface, but this does not argue against it being a deciduous tooth because permanent M1 lying just behind it erupts (now at age 6-7 years) while the second deciduous molar is still in place, and the second deciduous molar is lost only when replaced by a second premolar that erupts later (now at 10 years or a bit later).

The features shared in common between the two sites are principally overall body sizes inferred from the mandibles at the two sites. Reportedly, SOA-MM4 is smaller than LB1 and LB6. Size variation among humans in the Australomelanesian and surrounding regions should be considered in the context provided by the thesis of Dr. Bonita De Klerk (2012).

Curiously, the cranial fragment (SOA MM3) mentioned by Brumm et al. (2016) and listed in the Extended Data Table 1 by van den Berg et al. (2016) is neither pictured nor described in their paper. Since endocranial volume initially was a critical defining feature of “Homo floresiensis” and is disputed as being abnormally low due to developmental disruption, this omission is puzzling. The cranial vault bone of LB1 also has been stated incorrectly to be unusually thick since the initial description (Brown, et al. 2004), with this error repeated persistently since (e;g. Balzeau and Charlier, 2015). Consequently, even a small bone fragment might help correct this error as noted (Eckhardt, et al. 2014).

The new Mata Menge fossils do not help to resolve some of the most enduring questions that remain for bones from the LB site: endocranial volume, stature and limb proportions, taxonomic significance of chin presence or absence, and – perhaps still most important — whether the only relatively complete specimen, LB1 (which includes the only skull in the 62 bones it comprises from the site’s total of about 100 bones) is normal or abnormal. The most informative publications here include:

  • Jacob, et al. (2006) PNAS
  • Eckhardt, et al. (2014) PNAS
  • Henneberg, et al. (2014) PNAS
  • Eckhardt, et al. (2015) PNAS

The suggestion that comparisons among the Mata Menge and Liang Bua gnathic remains, in comparison to previously-known Homo erectus fossils, represent an “evolutionary reversal” overlooks an enormous body of work on size fluctuations in mammalian populations.

Similarly, there now is an existing body of knowledge about Homo erectus, s.l. populations. Many of these (Dmanisi) manifest small body sizes and extensive within-population variation; between-population comparisons of Dmanisi and other hominins with those from sites in other geographic regions (e.g. Nariokotome, Africa) show that, more than a million years ago, within and between-population differences approach some of those now found in our own species.

As they themselves have recognized, van den Bergh, et al. (in press 2016) provide data that are useful in countering the contention (by Argue and others) that the Liang Bua hominins probably are derived from unknown African early hominin ancestors). However, the case for such an African early hominin ancestor to the Liang Bua population never was plausible, and had been countered strongly by the extensive fossils discovered by Berger, Hawks, and their many colleagues in Dinaledi Chamber, South Africa (Eckhardt, et al., 2016).

Robert B. Eckhardt, Ph.D.
Laboratory for the Comparative Study of Morphology, Mechanics, and Molecules
Department of Kinesiology
Huck Institute of Life Sciences
Pennsylvania State University
University Park, PA 16802
Phone: 814-237-1901
Maciej Henneberg, PhD, DSc, FAIBiol.
Wood Jones Professor of Anthropological and Comparative Anatomy
University of Adelaide, Medical School
Adelaide, SA 5005, Australia
+61-8-83135479, fax 83134398, mobile +61 414 885 983
Institute for Evolutionary Medicine
University of Zurich
Switzerland
+41 44 635 01
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Mental obsessions of paleoanthropologists

Robert B. Eckhardt

Maciej Henneberg

 This reply has been written in response to an unrefereed self-promotional piece (Down syndrome theory on Hobbit species doesn’t hold [sic] to scrutiny, by Michael Westaway, Arthur Durband and Mark Collard) that was posted on The Conversation. All of the points, originally raised by these authors in a letter to the editors of Proceedings of the National Academy of Sciences of the United States (PNAS), were refuted by us in our own papers published by that journal.

Because we already have dealt substantively and completely in the published, primary scientific literature, with the criticisms made by Westaway, et al., here we simply will intersperse our responses within the text of this Conversation piece, distinguishing our comments with boldface type.

“Claims that bones found in an Indonesian cave are not the remains of a new species of extinct hominin but more likely modern humans suffering from a chromosomal disorder have been disputed by a new look at the evidence.”

“Last year Prof Maciej Henneberg, of the University of Adelaide, and his colleagues sparked intense debate among human evolution researchers when they published a pair of papers (here and here) in the Proceedings of the National Academy of Sciences.”

“Henneberg and colleagues argued that the so-called Hobbits – known by their scientific name Homo floresiensis – were not a new species of early hominin but just small-bodied modern humans with Down syndrome.”

The statements made in the immediately preceding paragraph simply are not true. They are misleading in several important senses. First, what has been presented in this round of The Conversation is not a new look at the evidence – and most certainly, there is no new evidence; there has not been any more skeletal evidence for more than a decade, despite research funds being spent in the unproductive quest for more skeletons that duplicate the morphological characteristics of LB1. Instead, what Westaway and colleagues have given us here is yet another repetition of the same statements that have been made many times before by the small group of paleoanthropologists who are fixated on reifying the invention of an invalid human species on the basis of wholly inadequate and erroneously reported data. This sort of approach — which involves, as here, “publishing” in a public forum the same, tired old points that already have been refuted in a major international generalist scientific journal — is most unusual in real science.

In our experience, in a vigorous but genuine scientific controversy a dialogue develops. Data are gathered, and logical arguments are advanced, based on a body of evidence that, in the usual case, increases with new investigations. In that context, when a particular statement has been proved wrong it no longer is accorded any weight, and the discussion can move toward resolution based on other evidence (and readers of The Conversation should note that we have presented many points – concerning limb proportions, pelvic anatomy, etc., etc. — that have not ever been addressed by supporters of the supposed new species). There has been no new skeletal evidence of “Homo floresiensis” discovered in Liang Bua Cave or any other site, while genuinely new evidence against the existence of this suspect taxon has been discovered elsewhere (e.g. Palau) and published on definitively by scientists (e.g. Dr. Bonita De Klerk, in a most thorough doctoral dissertation) who are not members of our research group.

Second, and much more important in the context of what should be honest scientific controversy, is the repetition of erroneous statements alleging that we have said that the Flores skeletal remains are those of “modern humans suffering from a chromosomal disorder” as written here by Westaway and colleagues. The misleading pluralization is important in this context. In the two papers that we published in Proceedings of the National Academy of Sciences (PNAS) on August 4, 2014, we went to considerable effort to make it clear that among the supposedly 15 separate “individuals” excavated from Liang Bua Cave there is evidence that, as far as we can tell, only one of them (LB1) is abnormal. The remains of the others simply are far too incomplete for us to be able at this time to make any reliable inferences from them about whether they show a chromosomal-based disorder, or indeed a disorder of any sort. It is possible that some of them might exhibit abnormalities, but that is not part of the inferences that we have drawn. Nor, as our papers document, would abnormalities in more than one specimen be damaging to our interpretation.

Third, the first of our two recent papers in PNAS makes it clear that our point about the non-existence of “Homo floresiensis” does not follow from a particular diagnosis of Down syndrome (however original and strong that diagnosis still appears). Rather, our deeply held skepticism about the tenability of any “new hominin species” being represented in Liang Bua Cave is based on the fact that the totality of evidence provided is so very slight (about 125 to 130 bones in all), and is so largely attributed to just one specimen (LB1) that appears pervasively abnormal regardless of the diagnosis. We repeat here, in addition, that the remains of LB1 have been misrepresented consistently in terms of its stature and endocranial volume, both of which have been exaggerated downward, whether by intention to mislead or by scientific incompetence in estimation. These are not mutually exclusive possibilities, as erroneous observations can stimulate fanciful interpretations. Overlooking the importance of the primary focus of the problem (body and brain size) and focusing on a minor point of anatomy (the chin) that is tangential at best to our analysis and the problem in general, should be seen as diversionary – not as an attempt to resolve a problem, but rather to perpetuate an illusion.

“It’s now more than ten years since a joint Indonesian-Australian team led by the late Prof Michael Morwood announced the discovery of the famous Hobbit fossils from the site of Liang Bua on the island of Flores, Indonesia.”

“Opinions about the significance of the fossils for our understanding of human evolution are generally accepted by the majority of the scientific community, although some researchers argue that the Hobbits are pathological modern humans.”

“But the Down syndrome argument does not hold on the basis of the evidence from the two lower jaws (mandibles) from the site, which belong to individuals known as LB1 and LB6, as we argue in a reply published this month, also in the Proceedings of the National Academy of Sciences USA.”

“Here we summarise the main points we make in our reply.”

“No support for a key claim”

“The LB1 and LB6 mandibles are crucial to Henneberg and colleagues’ argument. Both specimens have a “negative chin,” which is where the outer surface of the bone at the front of the mandible, below the incisors, recedes.”

“INSERT” [see Figure in original]

The statement above that “the LB1 and LB6 mandibles are crucial to Henneberg and colleagues’ argument” is patently false. Here is what we actually wrote in the second of our papers (Henneberg, et al., 2014) in PNAS (small type below comprises verbatim supplementary online material):

Microgenia (Micrognathia). LB1 formally exhibits microgenia or micrognathia, an unusually small chin. However, this feature needs to be considered in the context that there exist at least three alternative explanations for the appearance of microgenia in this specimen: (i) as one of the supposedly primitive features of a totally new human species (1); (ii) as a regional feature common in Australomelanesian populations (10); and (iii) as a developmental consequence of DS affecting the morphology of LB1 (55). The second alternative has been confirmed objectively as true (56), and hence casts extreme doubt on the first alternative as, at best, an unnecessary speculation. Plainly, the normal mandibular phenotypes observable in Australomelanesian populations (Flores, Palau, and elsewhere) are known entities, whereas advocacy of the same features as unique to a hypothetical new species is not only objectively falseas with a great many of the unique features of LB1, they are variable in expression and frequency, thus at best unusual only individually or in combinationbut also is the ultimate philosophical resort to an unknown entity. Just as clearly, the second and third alternatives are not mutually exclusive. The mandibles of LB1 and LB6, often said to be identical, quite evidently are not, by simple visual inspection (shown in figures 14 in ref. 57). This contrast is most readily apparent in ramus height, which is much shorter in LB6; in addition, the symphyseal region in LB6 is flatter and more nearly inclined toward the vertical than the more bulbous and receding anterior contour of LB1.

Pertaining to the second alternative, a mandible with a reduced bony chin is a regional characteristic found widely in normal members of Australomelanesian populations (10, 56, 58), a point that is ignored or denied consistently by advocates of the new species hypothesis; the extreme form of this misrepresentation is in figure 19 and its legend in ref. 57, which purports to disprove our documentation of the existence of a reduced (neutral or negative) chin in some Australomelanesians (frequencies of which obviously vary from population to population in the region) by showing a lateral radiograph on one unidentified Australomelanesian with a projecting bony mental tuberosity supposedly within a facial phenotype that has the appearance of a receding chin given by external soft tissue.The argument fails logically, because other than in a typological framework, any one specimen cannot disprove by proxy the existence of traits found in individuals among multiple populations in an entire geographic region. Moreover, there is reason to be skeptical of this particular example because the soft tissue profile is so tenuous that Brown and Maeda needed to delineate its contours with a line that is drawn in, obscuring if not altering the appearance of the soft tissue itself. Even if we do not reject the augmented evidence provided by this single unidentified specimen, it is obvious logically that the existence of any individual Australomelanesian with some bony chin projection covered by soft tissue that gives it a receding appearance cannot establish the generality of that hypothetical or actual anatomical conformation. Among 76 adult Rampasasa, 93.4% exhibited neutral or negative chins externally, on the basis of their soft tissue configuration. In the entire sample, only eight subjects (15.35%) showed a positive bony chin that appeared neutral on the basis of its soft tissue covering, and no subject exhibited a negative soft tissue chin that concealed a salient underlying bony chin (56).

Independently supporting the observation that results showing that reduced or absent bony chins among the Rampasasa (56) do not stand in isolation are the mandibles recovered on Palau (58, 59). Two mandibular fragments (B:OR-14:8-122 and B:OR-14:8- 771) are from recent adult modern humans (59). As noted by the authors of the Palau study, the former specimen lacks a vertical keel, distended inferior margin, T-shaped keel, T-shaped mental trigone, and associated mental fossae. The less complete second specimen lacks part of the symphyseal region but nonetheless also exhibits a highly reduced mental eminence.

With respect to the third alternative for a reduced chin structure, as shown in Table 1, microgenia is a feature that forms part of the facies commonly seen in individuals with DS regardless of the regional population from which they are derived. It should be noted, however, that although some ethnic(i.e., populational or regional) variations are known (60, 61), the facial morphology of DS shows some constant features (6267), as is true also for other serious developmental disorders such as cleft lip and palate (61). In general, the extensive biomedical literature on abnormal variation presents an entirely different perspective from the typological view widely accepted in paleoanthropology. This point is important because, although perspectives may vary, there is no rational basis for believing anything other than that there is only one set of evolutionary developmental principles that apply to hominin populations past and present. Because there is no extensive biomedical literature on the occurrence of DS in Australomelanesian populations, and also recognizing that the differences of the LB1 mandible from that of LB6 combine a further degree of symphyseal reduction with greater evidence for tooth loss and periodontal disease, in this regard, the LB1 mandible seems broadly consistent with a diagnosis of DS.

Summarizing the above material briefly, the statement by Westaway and colleagues that “The LB1 and LB6 mandibles are crucial to Henneberg and colleagues’ argument” simply is false. Whether these paleoanthropologists did not read the pertinent part of our paper (quoted in full above), or did read it and but could not understand it, or read it and chose deliberately to misrepresent it, is beyond our ability to discriminate. It is up to Westaway, Durband and Collard to tell readers of The Conversation which of these unattractive alternatives they wish to claim as an explanation for their misleading statements.

“The researchers who first described the Hobbit fossils argued that this trait sets the LB1 and LB6 mandibles apart from modern humans, who have a protruding chin, and aligns them with the early hominins, who have negative chins (as shown in the image below of the African Homo ergaster fossil OH 22 below).”

“The mandible of Olduvai Hominid 22 (OH 22) illustrates the archaic nature of the negative chin. Professor Colin Groves, Author provided”

[See original for figure]

The figure of the Olduvai Hominid 22 mandible provided by Westway and colleagues is interesting but irrelevant. It would be pertinent to disproving our thesis about the abnormality of LB1 only if we somehow were insisting that neutral or negative chins did not occur in previous hominin populations. But it is a widely known fact, even to undergraduate students as well as, presumably to Westaway, Durban, and Collard, that they did.  The real question is whether neutral or negative chins occur only in ancient hominin populations and not in any members of recent ones. But of course they do occur in some individual members of regional extant Homo sapiens populations, as we already have demonstrated.

“Henneberg and colleagues reject this claim. They contend that negative chins are often found among the indigenous people of Australia and Melanesia. Consequently, they suggest, the occurrence of negative chins on LB1 and LB6 does not stop them from being modern humans.”

“Henneberg and colleagues offer three pieces of evidence in support of their assertion that negative chins are commonplace among the indigenous people of Australia and Melanesia: two previous studies and a photograph (see figure S3 in the Supporting Information) of a mandible from an Australian archaeological site called Roonka.”

“Unfortunately, none of these pieces of evidence withstands scrutiny. One of the studies has not been published, which means that it has not been peer-reviewed and therefore does not meet the minimum standard of scientific quality.”

“The other study has been published in a respectable peer-reviewed scientific journal but has since been severely criticised.”

“And the Roonka mandible does not have a negative chin. This can be seen clearly in the figure (below), which compares a CT scan of the LB1 mandible with a CT scan of the Roonka mandible.”

“The mandible of LB1 (in blue) compared to that of an indigenous person from the archaeological site of Roonka, Australia. CT scan of LB1 courtesy Prof Mike Morwood; CT scan of Roonka 45 generated by Assoc Prof Arthur Durband, Author provided”

“Thus, there is no reason to believe that Australo-Melanesians often have negative chins and therefore no reason to overturn the assessment that the negative chins in LB1 and LB6 precludes their attribution to Homo sapiens.”

Westaway, Durband and Collard repeat here arguments that already have been dealt with in our response to the same points that they raised previously in their letter to PNAS. Briefly:

  1. The evidence that Westaway, et al. reject as not having been peer-reviewed is:

Hastuti J, Rahmawati NT, Suriyanto RA, Jacob T (2007) The chin in Rampasasa pygmies, West Flores. International Seminar on Southease Asian Paleontology Program Guidebook (Gadjah Mada University Univ, Yogyakarta, Indonesia), p.54.

The above paper was cited as reference 56 in the supplementary online material in our paper (Henneberg, et al. August 4, 2014 PNAS).

The original paper was presented at a major international conference to an audience of several hundred academic specialists. No one in that audience, including Mike Morwood (who was present at the conference) and many other “Homo floresiensis” advocates, raised any questions about the evidence. All of the slides from the paper by Hastuti, et al., were reproduced in the set of DVDs that were distributed to all conference participants. If Drs. Westaway, Durband and Collard were interested in perusing the actual data rather than disparaging evidence that they seem not to have examined, it would not have been difficult. We now have made all of the slides from the presentation available on our website (www.LiangBuaCave.org). There no longer is any excuse for their repeated denial of the obvious.

Incidentally, note the piece by Westaway, et al. in this most recent round in The Conversation, “…has not been peer-reviewed and therefore does not meet the minimum standard of scientific quality” — to use their own words. Of course, this is a double standard: Westaway and colleagues imply that peer review is critical as a test of scientific quality – except for their own expressions of opinion, which of course must be unquestioned wherever they are offered, for example here on The Conversation, regardless of its general audience.

Our own perspective is somewhat different. We believe that in scientific discourse, content is more important than form, which is why we ourselves are bothering to respond in this nonrefereed forum.  But that does not prevent us from observing that it is the contents of the communications by Drs. Westaway, Durband, and Collard that are deficient, whether posted as a letter to PNAS or, redundantly here, after disproof there. The simple fact of the matter is that Westaway, et al. sent a letter to PNAS challenging our findings. We were requested by that journal to respond to their letter, and did so. In our reply we showed that their criticisms were unfounded and distorted. The repetition here does not improve their accuracy.

  1. “The other study has been published in a respectable peer-reviewed scientific journal but has since been severely criticised.” The paper referred to here is:

Berger LR, Churchill SE, De Klerk B, Quinn RL (2008) Small-bodied humans from Palau, Micronesia. PLoS ONE 3(3):e1780.

Severely criticized? Really? Oh, my heavens. Just imagine, severe criticism in science. How novel, how utterly devastating.

Anyone familiar with how science works will realize that criticism is part of the process by which data and theories are evaluated. Ideally scientific criticisms are substantive in nature and accurate in their expression, but as in the case of the piece here by Westaway, Durband, and Collard, in paleoanthropology such conventions are not always observed. Those familiar with the field of human evolution will know that, to choose another example, Raymond Dart’s 1924 description and diagnosis of the Taung skull as the first australopithecine was “severely criticised” – really severely criticized, for decades — and Taung was not accepted generally as a hominid until the mid-1950s, and then chiefly because the fraudulent Piltdown find was removed as a valid specimen. Nonetheless, severe criticism is not the same as presentation of appropriate scientific disproof. Piltdown, “Eoanthropus dawsoni,” was defended widely for decades; in the case of “Homo floresiensis” we are just into the early years of our second decade of attempted defense of the indefensible by its partisans, in the face of growing contrary findings. The Palau skeletons described by Berger, et al., however criticised, constitute regional evidence that is highly pertinent to discussions of the Liang Bua Cave remains.

“More inconsistent data”

“The chin is not the only feature of the LB1 and LB6 mandibles that does not support Henneberg and colleagues’ argument.”

“A study that was published several years ago identified a number of other traits that LB1 and LB6 share with early hominins but not with modern humans.”

“One of these traits can be seen in both the photograph of the OH 22 mandible and the CT scan of the LB1 mandible. On the inside of the front of the mandible there is a bulge. Such “buttresses” are common in early hominin mandibles but are not found in modern human jaws.”

The statement above, as with many others made by Westaway, et al., is incorrect. Whatever the morphology of the OH22 mandible dated to very roughly a million years ago and found on another continent, Africa, unless evidence is provided to connect its population with that represented by the Liang Bua Cave remains, the specimen is irrelevant to observations on mandibles of recent humans, which is the point at issue here. The anterior symphyseal portion of the mandible is highly variable in normal human mandibles from the region that includes Palau and Flores. See Figure 5 and its caption from Berger, et al. (2008).   

“A second trait that distinguishes the LB1 and LB6 mandibles from those of modern humans is the presence of [a] distinct gap between the end of the tooth row and the rear section of the jaw.”

This statement is untrue and ignores evidence that already has been presented in the response that we made in PNAS:

Noerwidi S (2012) The significance of the Holocene human skeleton Song Keplek 5 in the history of human colonization of Java: a comprehensive morphological and morphometric study. M.A. Thesis, Erasmus Mundus (Muséum national d’Histoire naturelle).

As indicated in the title of the reference, Song Keplek 5 is a Holocene human mandible that exhibits a retromolar sulcus. Other examples of retromolar sulci could be cited from elsewhere in the world.

 It is difficult to decide which is more indicative of scientific malpractice on the part of Westaway, Durban and Collard: initially being unaware of evidence from the region pertinent to Flores that refuted their statement before it was published in error; or their choosing afterward, as here, to pretend that this evidence contrary to their position does not exist.

“A third trait that links LB1 and LB6 with the early hominins rather than modern humans is the form of their tooth roots.”

More than a decade ago I published a paper that established clearly the point that numbers of tooth roots occur polymorphically in human populations distributed over time and space:

Eckhardt RB (2003) Polymorphisms past and present.  Human Biology 75(4):559-575.

Once again, Westaway, et al. choose to ignore data that contradict factually a position that is counter to the one that they would prefer to be the case.  

“Henneberg and colleagues ignored these traits, but their presence in LB1 and LB6 provides strong support for the hypothesis that the Liang Bua fossils are the remains of early hominins and not those of modern humans.”

As noted in our response published in PNAS and noted again here, we did not ignore these traits, but showed – with evidence – that Westaway and colleagues simply were wrong.

It should be added that the “remains of early hominins” from Flores to which they refer all are dated – however questionably – to a time within the last few tens of thousands of years during which only members of our own species are known everywhere else in the world. The Flores skeletons are not “early hominins” somehow inexplicably caught in a time warp, but instead contemporaries of other Homo sapiens populations and exhibiting features – normal and abnormal – known to be found in other members of our species.

“Taking it on the chin”

“The Down syndrome hypothesis is the latest in a long line of attempts to explain the features of the Liang Bua hominin fossils as pathologies.”

Here again, Westaway, Durband, and Collard continue their misrepresentation of our position. We have not presented data establishing  that ALL the Liang Bua hominin fossils” – note the plural again used here by Westaway and colleagues, as well as the misleading designation as fossils specimens that are not — are pathological. Instead we have made a strong case that the most complete specimen, LB1 (which in and of itself comprises the great bulk of the skeletal elements from the cave), manifests developmental abnormality. The remaining few bones from the cave representing other skeletons are inadequate to allow reasonable certainty on the point of whether the individuals that they represent were normal or abnormal, and at this point there is no need to posit abnormality for all of them.

The LB1 specimen clearly is abnormal, however, and this point cannot be avoided by other than wishful thinking based on misconstrued data.

“It should be the last, we think.

The mandibular evidence disproves the idea that LB1 and LB6 are modern humans, and there are a number of other lines of evidence that do so too, as the work of Prof William Jungers, Prof Peter Brown, and several other colleagues has demonstrated.

It is time for the field to move on. The Hobbits are a new species of early hominins not modern humans with Down syndrome or indeed any other pathological condition.”

It is difficult to conceive of a more self-servingly unscientific statement than the one immediately above, that “It is time for the field to move on.” This statement is particularly out of keeping with the best traditions of science, even a scientific field as commonly partisan and insular as paleoanthropology.

Raymond Dart published his brilliant and prescient description and diagnosis of the Taung child’s skull in 1924, and was attacked widely and savagely for his effort. But neither he, nor even his critics, who turned out to be wrong for all sorts of reasons, called for an end to the quest for pertinent evidence. Indeed, one of the most intellectually and empirically heroic – and I use that term, “heroic,” with full cognizance of its meaning — chapters in evolutionary biology is represented by the work of Dart, Broom, Schepers, and Robinson. This small group of outnumbered and underfunded researchers worked through the 1920s, 1930s, 1940s, and early 1950s to recover steadily more and more abundant and diagnostic australopithecine remains from a variety of sites. MH knows well about this quest, having been a successor to Raymond Dart in his Chair at the University of Witwatersrand in South Africa. Being outnumbered and underfunded does not equate with being wrong. Science is not a democracy but rather a meritocracy, one in which superiority of evidence and reasoning in the long run trumps popularity in the short run.

Where is the spirit of Dart and his colleagues in the debate over the sparse and fragmentary human skeletal remains from Liang Bua Cave? Reiterated rhetorical misrepresentation of our work will not serve. Nor will a continued pattern of garnering research funds for archaeological work that produces no tangible results. Science deserves better than this farrago.

Robert B. Eckhardt

Maciej Henneberg

15 March 2015

 

 

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Rampasasa Mandibles

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Rampasasa mandibles.pdf

 

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Flores forensics, faces, and facades

(Open letter 2 September 2014 to Chloe Ross of 9News, Australia; edited and posted 2 September 2014 on www.LiangBuaCave.org)

Robert B. Eckhardt and Maciej Henneberg

The overall impression that one gains from the latest attempt to market the “mystery hobbit” is a swirl of confusion, misinformation – and scholarly desperation. That is not a healthy mix, and we excuse readers of the 9News pastiche for being confused; that outcome is not accidental, but rather seems purposeful.

At first glance we have what appears to be a story by Chloe Ross:

Indonesia’s mystery ‘hobbit’ unveiled by Australian scientist (http://www.9news.com.au/national/2014/09/01/17/43/flores-hobbit-is-given-a-face-by-australian-scientist#1gDVHe0GxSOEPuZe.99).

That story reports on what is represented as new work by Dr. Susan Hayes, a NSW criminal investigator who uses forensic techniques to reconstruct faces for remains found at crime scenes: “Discovering the Hobbit of Flores, Indonesia,” August 28, 2014 (Australian Geographic, #122, Sept – Oct 2014). We offer here no critique of the creative work by Dr. Hayes; forensic reconstruction is a demanding combination of science and art, and in the brief report she carefully qualifies her results, as is appropriate. Even best face reconstructions from skulls rarely lead to forensic identification because so much detail of the face surface (wrinkles, moles, lip thickness, facial hair) can’t be read from the skull. They are left to the artistic licence. (As an aside, the full facial reconstruction based on LB1, the only known skull from the Liang Bua Cave on Flores, looks quite similar to some Down syndrome individuals in having a relatively wide face and reduced chin.)

The reconstructive work by Dr. Hayes is not new. It was featured on another Australian blog, The Conversation, around May of 2013. Same pictures, same text.

The current story, as it develops, is rather like a set of Russian Matryoshka nesting dolls. The outer wrapper is the 9News story by Chloe Ross; peel that away and one encounters a report about the reconstruction, ostensibly by Dr. Hayes; but inside is the continuingly bizarre tale spun by Bert Roberts. Here, as elsewhere, what Dr. Roberts writes is replete with error, innuendo, and disinformation. He appears to believe what he writes, but sincerity is no substitute for objective testing. As noted by the Nobel Prize winning physicist, Richard Feynman in “Cargo Cult Science,” his Caltech commencement address in 1974, in science “the first principle is that you must not fool yourself – and you are the easiest person to fool. So you have to be very careful about that. After you’ve not fooled yourself, it’s easy not to fool other scientists. You just have to be honest in a conventional way after that.”

Dr. Roberts appears to confuse intensity of belief with objective verifiability, continuing to disgorge factoids that have been shown to be incorrect, ranging from diagnosis of the sex of LB1 (a statement based on unsupported guesswork, while we have presented evidence from a scoring system that shows LB1 to have been a male, lightly built as would be expected for the small body size), through its stature (once more said here by Dr. Roberts to be “only one meter tall,” again disproved at multiple levels not only by our own research, but by a definitive thesis written entirely independently of our group by Dr. Bonita De Klerk of the University of Witwatersrand, South Africa, with Dr. De Klerk writing directly that the stature reconstructions by Drs. Brown and Morwood are wrong and should be corrected in the scientific literature) to the statement that LB1 had “disproportionately large feet,” while in fact the feet are in the very small end of the range for living humans, but associated with a femur that is quite abnormally short – as is common in patients with Down syndrome. These are not matters of opinion, but rather of fact, which we have presented in detail in the scientific literature since 2006 without effective contradiction. Dr. Roberts and his colleagues behave as if merely stating erroneous and misleading statements over and over again constitute disproof. It does, but only in Wonderland.

Finally we have the statement:

“Dr Hayes’ report comes just weeks after furious international dispute erupted over the publication of a paper which claimed a hobbit man of Flores was a modern human with Down syndrome. The research was widely denounced by scientists around the world.”

If one goes to the link brought up by the highlighted line immediately above (“claimed a hobbit…Down syndrome”) one finds only one of the two papers that we recently (4 August 2014) published in Proceedings of the National Academy of Sciences of the United States (PNAS) – and it is the wrong paper!

The reference cited by one of the dolls, seemingly Dr. Roberts, is our paper which offers definitive disproof of the validity of the taxon “Homo floresiensis” but does not offer a specific diagnosis for the abnormality manifested by LB1 (still, after a decade, the only skull known). It is the second paper that offers that diagnosis. For those interested in the science involved, rather than the hysteria, here are links to the two papers:

Rare events in earth history include the LB1 human skeleton from Flores, Indonesia, as a developmental singularity, not a unique taxon

and,

Evolved developmental homeostasis disturbed in LB1 from Flores, Indonesia, denotes Down syndrome and not diagnostic traits of the invalid species Homo floresiensis”  Both of those papers are on PNAS Open Access so that anyone who wished could read them without cost or complication. We suggest that this might be a good starting place for Dr. Roberts and other people who have “denounced” the papers.

In closing we note that “denounced” seems a strange epithet to encounter in a scientific controversy. It seems more commonly associated with Stalinist era show trials and the like. We do not believe that we ever would be inclined to think in terms that would lead us to having “denounced” a scientific paper. There certainly are tactics of which we most certainly would disapprove. These include misrepresenting an opponent’s hypothesis in a distorted manner, the easier to attack it as a straw man. They also include, while acting as a referee for a scientific journal, taking valid, straightforward evidence that is correct by examination, and stating that it is incorrect, under the protection of anonymity, to block publication. They also include threatening a lawsuit for having allegedly taken a photographic image of a slide in a public presentation, when it was physically impossible for that act to have been done, then failing even to apologize afterward for the threatened but unconsummated legal threat. They further include taking the contents of a paper that we submitted for publication, arguing to the journal that that paper should not be published, then passing the contents of the paper to a colleague who then used the contents in that person’s own published work. As we have said, although we doubt that we would “denounce” people for having committed such actions, we would disapprove of them as being far below the standards for normal scientific discourse. But we will state, and stand willing to back up these contentions with all of the detail that might be necessary, that our detractors, the supporters of “Homo floresiensis” as “…one of the most remarkable anthropological discoveries of the last 50 years” according to Australian Geographic Editor John Pickrell, have done all of these things in their attempt to suppress any alternative to their viewpoints.

As far as we can tell, the number of scientists who have made intense attacks on our work were very small, though highly vociferous. Additionally, so far all of their criticisms, for example those offered by Dr. Colin Groves in an early piece published by ABC Australia and repeated widely before we forced corrections in print, simply have been wrong, as were some of his sources on the web site of the Australian National Museum (for some of this material see our web site www.LiangBuaCave.org).

Readers should make no mistake. This controversy is not just about the interpretation of the only specimen from the curious Liang Bua Cave excavation to have a skull (the “hobbit” reconstructed by Dr. Hayes). It is not just about the supposedly large number of other “individuals” recovered with LB1; this notional number now is up to 14 in some reports, without any photographic documentation of what they look like, individual by individual. Having seen the sparse and highly fragmentary remains firsthand ourselves, we know that there is less there than the actively-created impression of a large and uniform sample than is widely believed (please test us on this – show the photographs and prove us wrong). It is a controversy about how many people in the discipline of paleoanthropology do “science” as a matter of course, publishing inflated claims that commonly cannot stand up to public scrutiny—hence the attempt to keep the primary evidence under highly restricted access, as is the case here.

It is a common shibboleth that science is “self correcting.” In practice that rarely is the case. Far more often than not, scientific errors are exposed by small numbers of researchers who are willing to pay a high price professionally to correct the record, an endeavor for which there is little or no reward, and much casual calumny.

We had not thought of news media as fertile grounds for the hunting of heretics, believing that a more valid calling of the press was to look critically at widely held but shallowly based misimpressions. We remain ever hopeful that this yet may prove to be the case.

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Dean Falk’s nonce sense

Open letter, 21 August 2014, to Hannah Devlin of the Times (London), edited and posted 24 August 2014 on www.LiangBuaCave.org

Written in the first person by Robert B. Eckhardt, edited and co-authored by Maciej Henneberg

Dear Ms. Devlin:

I thought that your longer piece in the Times of London (http://www.thetimes.co.uk/tto/science/article4179086.ece), written several days ago on the evolutionary connection of Hallucinigenia to the extant velvet worm, was a succinct report on an elegant and long overdue bit of science: (http://docs.newsbank.com/s/InfoWeb/aggdocs/AWNB/14FC8920EB4E0770/0EB90CA9CF65E92A?p_multi=LTIB&s_lang=en-US ). It is gratifying to see solid, objective closure given to scientific problems that in previous years were presented as fabulous (in all of that word’s denotations and connotations).

Hallucinogenia was part of the Burgess Shale fauna around which Stephen J. Gould spun imaginative but sometimes unlikely tales in Wonderful Life. But even lost, lamented Steve at his most creative extreme is likely not to have matched the tales that have been invented and merchandised this decade past about “Homo floresiensis,” aka “The most important find in human evolution for the last 100 years.”

Just below the Hallucinogenia story for some reason you inserted an untitled paragraph, excerpted here: “? Scientists have dismissed as nonsense new research suggesting that the so-called hobbit man of Flores was simply a modern man with Down’s [sic] syndrome….The paper failed to include any comparisons between people with Down’s [sic] syndrome and the fossil [sic]. Professor Dean Falk…told The Observer: ‘If it had, you would see clearly that they look nothing like the Flores specimen. The idea is nonsense.’”

No scientists are named in your excerpt other than Dean Falk, who is part of a very small group of paleoanthropologists who believe that science is advanced by spreading rumors to journalists rather than gathering data broadly instead of narrowly, and only then testing hypotheses, before making nonce comments. It is impossible to stop that sort of behavior, but neither must one credit it. Despite Dr. Falk’s claims, it is the “hobbit” story that, in the context of evolutionary biology, is an absurdity, however persistently and passionately defended. As an aside, I believe that hobbits and dwarfs have their places, but it is in literature rather than as inappropriate ornamentation used to divert attention from deficient inferences that rest chiefly on social validation: see my short essay on “Dean Falk’s Flores Circus” at www.LiangBuaCave.org and posted separately on the site of the British Museum of Natural History, NaturePlus as well as elsewhere.

I am a great fan of J.R.R. Tolkien’s work as is my wife Carey, a Medieval paleographer who has done serious research in the field including, among other works, publication of the 14th Century Thomas Castleford’s Chronicle in the Early English Text Society series. Since we work together we have been to the Liang Bua Cave multiple times, with Maciej Henneberg, as well as having seen and studied with other members of our group the bones from Flores and the small people still living there. All of us, knowing some literature and science, feel that when we visited Flores we would have recognized a hobbit. We didn’t see any, dead or alive. Per the title of the press release that accompanied our group’s previous paper on the subject (by Jacob T, et al.) in PNAS, “No hobbits in this shire.”

So far, two framing hypotheses have been offered by the Hobbiteers to explain the reported characteristics of the alleged new hominin species (sorry, though never a member, I am of the Mickey Mouse Club generation in the U.S.A. so see many immature behavioral resemblances between the Hobbiteers and the Mouseketeers, though from my preteen years I still think that Annette Funicello was perkier than any of the present Hobbiteers). The hypothetical taxon “Homo floresiensis” first was said to have descended from Homo erectus during long isolation on the island of Flores, with resultant dwarfing to tiny body and brain size. Subsequently an alternative rationalization was offered, deriving the hypothetical new hominin from an unidentified African ancestor that already was characterized by small body and brain size before it migrated between one and two million years ago to Flores over an unknown route, conveniently leaving no remains anywhere along the way. These framing hypotheses are mutually contradictory. Moreover, both are logically indefensible, together or separately, and in any case neither fits all of the biological and cultural evidence without a lot of selective presentation of data, concealment of inconvenient elements, special pleading, and frantic ex post facto jury-rigging.

The latter origin myth (stealth migration from early Africa to Flores) is effectively untestable aside from the Godot strategy: waiting forever for something, anything, to be found along the way; while the former trope (island dwarfing to the extent of separate species status) has been tested by the discoveries on Palau, by which hypothesis test “Homo floresiensis” failed. Palauans from the same broad regional (Australomelanesian) human population of several thousand years ago had very small bodies but brains within modern range for Homo sapiens. Consequently, the LB1 skeleton, with the only known skull from the Liang Bua Cave site, is one off, or a “singularity” as we have termed it, drawing the parallel to mathematical functions having a point that “blows up” under certain circumstances (in this case, that circumstance being examination without rose-colored glasses or the Mallinkrodt Institute CT scanner that eliminates problematical anatomical parts and substitutes impression for quantification). Failure of the Island Isolation framing hypothesis appears to be why the Stealth Migration hypothesis then was invented to account for the unusual bones and unsurprising stones from Flores.

Against this background we have framed and tested an alternative hypothesis: that the Liang Bua Cave skeletons represent a population small in body size but otherwise normal except for the LB1 specimen, which is developmentally abnormal. Because of the alternative framing hypothesis that we have offered, our group finds itself being smeared (a tacky enterprise which your paragraph has furthered to some extent, however unintended). Our main choices are either to ignore a determined disinformation campaign that operates at the edge of slander to impugn our scientific integrity and veracity, or to play a game of whac-a-mole with various smug paleoanthropologists (you quoted Dean Falk, but there are some others with similar fantasies and agendas). My own assessment is that these few highly vocal paleoanthropologists are in the situation often depicted in the Wile E. Coyote cartoons, which are not sophisticated but are symbolically evocative of an insupportable situation as yet unrealized – up in the air inertially before a kinetic fall. Looney Tunes are where you find them, whether Hollywood in California, or Florida and New Mexico.

Another perspective is the one posed decades ago in the financial realm by the British-American inventor of the discipline of security analysis, Benjamin Graham: “In the short run the market is a voting machine; in the long run it is a weighing machine.” For the last decade the vast majority of paleoanthropologists, science writers, and bloggers have been voting for “Homo floresiensis” as a new species with wondrous attributes. The weight of rejection will come as more of the initially credulous onlookers join us as sceptics. In contrast with a more credible assessment (presented in our published papers and put into broader interpretive perspective in the several essays on http://www.LiangBuaCav.org), Dean Falk for years has retailed the myth that the battle to defend “Homo floresiensis” is one in which a tiny band of courageous scientists, not surprisingly, rally ‘round Dean Falk as sort of a modern day Joan of Arc among them, bravely holding aloft not the Lily Banner of France but the Flores hobbit hankie, handy for knowing which way the breeze of media fashion is blowing. These warriors must hold out against vast armies of reactionary human evolutionary biologists who are irrationally defending the status quo (which really is ineffably more complicated, but who needs complex reality when a stirring – and self promoting — simplistic tale can be told?). Of course, anyone with even a passing knowledge of the matter knows that precisely the opposite is true. Despite the easy verifiability of the real situation, the myth has Dr. Falk shedding her woman’s weeds not for chain mail and a charger but for a lab coat and the trusty Mallinkrodt Institute magic scanner. Thus attired and armed, she assumes the mantle (over or under her lab coat, I’m not sure) of Raymond Dart, who on behalf of Australopithecus africanus really did, largely alone at first, then subsequently with the help of Robert Broom and a very few others, meet massed opposition from the field for about thirty years during the enduringly specious but widely accepted reign of one misleading individual British skull. Dart’s is an exemplary story that is true; Dr. Falk’s is a distorted facsimile; Gucci it ain’t, but street vendors are legion and sell on the cheap.

Raymond Dart worked in an environment shaped by the highly popular find at Piltdown that was endorsed as a valid stem human species, Eoanthropus dawsoni. A majority of anatomists and physical anthropologists (some of them, such as Sir Arthur Keith, highly influential) believed in it. Piltdown was doubted by only a few respected comparative anatomists such as William King Gregory, and by other more marginalized but still highly original morphologists such as Franz Weidenreich. Dart’s support for the hominid status of Australopithecus africanus de facto put him in the position of being against the contrasting pattern represented by Piltdown.

In obsessively defending the validity of “Homo floresiensis” and attacking all unbelievers, Dean Falk publicly represents herself as the present counterpart of Raymond Dart during his years of struggle on behalf of Australopithecus africanus as a valid, primitive hominin species. But… Professor Falk, I knew Raymond Dart. Raymond Dart was a colleague of mine. Professor Falk, you’re no Raymond Dart.

I knew Raymond Dart only to a modest degree but wish intensely that it had been more. During the early to mid 1970s, he offered me advice when I was challenging, at great professional cost, the evolutionary status of Ramapithecus as the earliest hominid. Now Ramapithecus is no more than another of paleoanthropology’s sequential embarrassments that are forgotten as fresh ones are being engendered. Our contact occurred during the period when Dart consulted regularly at the Institutes for the Achievement of Human Potential in Philadelphia, work made possible because Dart was not only a superb comparative anatomist, but also a medical doctor with interest in diagnosing and helping children believed to have developmentally abnormal brains. Later I also met him in South Africa and was surprised but pleased that he remembered me after nearly a decade. Like many truly great scientists, he was magnanimous in creating and sharing knowledge rather than building and protecting personal status.

Among other members of our research group, Maciej Henneberg has a connection of an indirect sort with Raymond Dart. Dart was for many years Head of the Anatomy Department at Wits (University of the Witwatersrand) in Johannesburg, South Africa. After a long tenure in the position, Dart was succeeded as Wits Anatomy Department Head for more than thirty years by Philip Tobias (who, incidentally, was a reader/referee of our 2006 PNAS paper on the Flores skeletons, endorsing our steadfast views – then as now — that LB1 was not a valid type specimen for a new hominin species, instead being a developmentally abnormal individual). In turn, after a stint in a Communist prison for his activity as a Solidarity leader at Mickiewicz University in Poznan, Poland, and prior to his present appointment as the Wood Jones Professor of Anthropological and Comparative Anatomy at Adelaide, Maciej Henneberg, too, was Wits Anatomy Department Head for a period following Philip Tobias.

It also is worth mentioning briefly here Dr. Kenneth Hsü, the other senior member of our team. According to another journalist, an anthropologist named William Jungers, who is based in Long Island, New York and a common collaborator with Dean Falk, is reported to have said that Dr. Hsü committed “an abuse of the PNAS review process, because Dr. Hsu is a hydrologist and a member of the National Academy (foreign member)….” Compartmentalizing Dr. Hsü as a hydrologist is comparable to describing Michelangelo as a ceiling painter; as with some other things that Dr. Jungers has said when faced with views that he finds challenging intellectually, his recent ad hominem characterization of Dr. Hsü is a faint simulacrum of the truth. Dr. Hsü’s pertinent involvement in our three papers published in PNAS (one in 2006, two in 2014) derives, among other things, from his knowledge of factors influencing the dynamics of sea level change, a matter of great importance to understanding the probabilities and routes of contact between populations on Flores and elsewhere in the region. Among a great many other attainments and distinctions, Dr. Hsü has received the Twenhofel Medal (the highest award from the Society for Sedimentary Geology); the Penrose Medal (the highest honor of the Geological Society of America); and the Wollaston Medal (considered the highest honor in Geology, with previous recipients including Charles Lyell, Thomas Henry Huxley, and Charles Darwin). If questioning some aspect or application of evolutionary theory (as Dr. Hsü has done several times) makes one an anti-evolutionist, then all four of these gentlemen perhaps have earned the epithet of “anti-evolutionist” along with most others in the field who think at all critically. But academics who attack the reputations of others who disagree with them, do so in the hope that some of the diversionary tactics will work by deflecting attention from substantive research findings. Unfortunately, they sometimes do, at least for a time. So what?

Make no mistake. Before writing and publishing our two recent papers in PNAS, we knew that there would be an attempt to exact a reputational penalty for what is at its core not only a challenge to the interpretation of “Homo floresiensis” as such, but also is an attempt to shine a spotlight onto the central dogma of paleoanthropology: mophological difference = species distinctiveness; this assumed identity statement then usually is framed within a Kiplingesque Just-So Story, the more exotic the better. If one visualizes the challenge to “H. floresiensis” as a valid species and the challenge to paleoanthropology’s central dogma as circles in a Venn diagram, they overlap quite extensively, since the first very largely is a subset of the second. A third circle overlapping these two is the scientific refereeing system as it now exists in a very imperfect form (to be generous); abuse of the supposedly impartial refereeing system is an increasingly serious problem in all of science, but nowhere more than in paleoanthropology. There is neither time not space here to address, as it should be more fully, this larger matter of rigged refereeing. However, there should be no doubt that the cries of outrage on the part of Dean Falk, Chris Stringer, William Jungers, and a few others, are not raised legitimately over our referees’ abilities or suitability, but because somehow we managed to get our ideas about the Liang Bua Cave specimens out into the open where the expanded body of evidence can be considered and the resultant new hypotheses tested. We hope that many evolutionary biologists will be willing actually to read our two recent papers (which are available free on PNAS Open Access). After studying the papers, as well as the previous literature on the Liang Bua Cave skeletons, readers who have a sense of academic integrity might think about the contents and implications of the papers before posting comments or writing replies, something that I have not seen much evidence of so far. To comment without reading what we have written represents the best (that is to say, the worst) tradition of attacking the messenger so as not to have to deal with the message, and also thereby giving others – particularly science writers and other journalists — an excuse for also not reading the papers.

What about Dean Falk’s statement that “The paper failed to include any comparisons between people with Down’s [sic] syndrome and the fossil [sic]… ‘If it had, you would see clearly that they look nothing like the Flores specimen. The idea is nonsense.’”

Dr. Falk’s statement is untrue on its face. It does not acknowledge that “comparisons” legitimately and conventionally can be verbal as well as visual (as well as auditory, olfactory, and tactile, not applicable here). This specially restricted usage is not original with Dr. Falk, however. In it she echoes the sentiments of Humpty Dumpty in Lewis Carroll’s Through the Looking Glass:

“When I use a word,’ Humpty Dumpty said in rather a scornful tone, ‘it means just what I choose it to mean — neither more nor less.’

’The question is,’ said Alice, ‘whether you can make words mean so many different things.’

’The question is,’ said Humpty Dumpty, ‘which is to be master — that’s all.”

In science “mastery” properly refers to level of understanding of the subject matter, not as here, the power to restrict expression about it.

The broader misrepresentations attributed to Dr. Falk in the brief quote range from disingenuous to deceptive.

  1. The Liang Bua Cave remains are not fossils in any sense other than the Latin literal meaning of “something dug up from beneath the surface of the ground.” They are rather soft and fragile unfossilised bones (to such an extent that in 2005 I would not handle many of them for fear of causing damage); thus applying the term fossil to these bones from Flores implies a false antiquity. This misleading aura also pervades the first two papers that appeared late 2004 in Nature on “Homo floresiensis” as well as many of the largely descriptive pieces published on them in the Journal of Human Evolution. All of those papers, with their rhetorical but anatomically equivocal comparisons with Homo erectus and earlier hominins, could have used some critical referees; but of course unlike our papers in PNAS, whose readers are acknowledged freely and thus exposed to criticism, referees of the Nature and JHE papers remain covert and cannot be called to responsible account.
  2. There is not one paper recently published by us in PNAS. There are two. The first presents the evidence that LB1, the type specimen of “Homo floresiensis,” is developmentally abnormal. This condition necessarily bars it from being accepted as the type specimen of a valid, unique species. In that first paper we make the point that regardless of any particular diagnosis, “Homo floresiensis” is fatally flawed as a valid taxon. The Falks of the world will, by sidestepping the logic, ignore that inconvenient impediment to their views, continuing their practice of years past. The second paper then builds on that critique of species status to outline the basis for a diagnosis of LB1 (and as far as we can tell from the sparse evidence, only LB1), as presenting a strikingly good match for an individual with Down syndrome. Again, counter to Dr. Falk’s deceptive statement that we failed “to include any comparisons between people with Down’s [sic] syndrome,” these comparisons are made in our Table 1 and extensively in one of the online supplements, where we provided five pages of detailed descriptive comparisons between LB1 and individuals with Down syndrome. The matches in facial asymmetry, pelvic morphology, and inter-limb proportions are particularly apposite.
  3. What of visual comparisons? In their attacks on previously attempted specific diagnoses for the anomalies seen in LB1 (e.g. Laron syndrome, endemic cretinism – neither of which was ours), a key tactic used by the Hobbiteers was presentation of one or a few visual examples (such as radiographs) that were said not to match. In the case of Down syndrome this inherently typological strategy will not work except as allowed by credulous or complicit journal editors. If past is prologue, the extremely great range and diversity of syndromic expressions (here, in Down syndrome) will be denied, misrepresented, or not represented at all. This is not to say that our hypothesis cannot be tested, but rather that we doubt most seriously that Dr. Falk and her collaborators have the inclination and ability to do this adequately and objectively, or that sympathetic journal editors will oblige them to do so.
  4. From previous observations of the papers that we have seen from the supporters of “Homo floresiensis” we anticipate that regional variation in human populations will be ignored. Typical of this stratagem is the repeated comparison of the LB1 skull with that of some strikingly contrasting specimen of an unidentified extant Homo sapiens individual (the image having been used persistently on the web sites of Nature and National Geographic, among others), almost certainly from a European population. The visual effect of such a comparison is to have scale effects swamp other points of visual comparison. In our first paper, “Rare events…,” Fig. S2 takes regional anatomical features into account, comparing the LB1 skull with that of Liang Momer E, a later human burial on Flores, also using a more comparable anatomical orientation. Among recent humans – a sample that includes the individuals represented by bones from the Liang Bua Cave as well as those on Palau – geographic regional population resemblance is critically important. And overall, variation within and between populations is far more extensive – and patterned — than has been acknowledged by many paleoanthropologists.

What about the potential comparative evidence from the Liang Bua Cave itself?

Part of the framework of casuistry propping up “H. floresiensis” is that the species is represented in the form of a fairly large number of individual specimens. Numbers such as 9, 11, 13, 14 often are mentioned as comprising the sample. The resultant impression is incredibly misleading. The LB1 specimen has the only skull, along with about a third or half of the rest of the skeleton (most long bones, incomplete clavicle, most foot bones, a few carpals, etc.). But the tally of bones per individual falls off sharply from there. Probably next is LB6, with a mandible, partial scapula, several carpals, etc. From there the tally of bones per each individual skeleton decreases steadiy, finally dropping to a scatter of fragments. Maciej Henneberg and I know that this is the case because we are among the very few people outside of the selected group of “H. floresiensis” supporters to have seen all of the bones in Indonesia. We have been trying — not only without success but completely without any acknowledgment that the matter is of any interest — to have Peter Brown and the Indonesian curators publish photographs of the set of bones assigned to each of the individuals enumerated (but so far not systematically illustrated). There exist published photos of LB1 (repeated everywhere), but not any comparable photos for any of the remaining individuals. For the most part, only photographs of selected bones have been published. So now let’s have them: LB6, LB2,…LB14, etc. Then there should be, I think, one last photo that shows all of the unassigned bits; these will be small, indeterminate, and fairly numerous. Assembling each of the sets of individual bones would not require much time (the sorting and enumeration must have been done already, else whence the notional numbers of individuals?); nor would taking the photographs be difficult. Any one of several journals would publish such a set of photographs without demur or delay. If this were done, then everyone would have a more realistic visual image of the amount of evidence that actually exists for the material recovered from Liang Bua Cave. Until then, they don’t. And it is particularly baffling that almost no one seems to care. It seems that we have faith-based paleoanthropology. Because I’m not long on faith, I’ll offer a hypothesis: photographs for each separate individual in the total sample of bones, as called for here, will not be published. That hypothesis easily could be tested, but it will not be because to do so would shatter the carefully built impression of numerous individuals showing high phenotypic uniformity.

As a well-regarded journalist you occupy an important position in this scientific standoff. One small step would be to clarify in print that you merely were repeating, not endorsing, Dr. Falk’s biased characterization of our work. Beyond that, we hope that you will take another step that should be considered as entirely neutral, but potentially of enormous benefit to the study of human evolutionary biology in raising the level of discourse about the Liang Bua Cave bones: helping to catalyze release of the requested full set of photographs, one per individual, of all of the supposedly numerous skeletons from the cave.

In your longer article that preceded the paragraph cloned from the Guardian Observer, you noted that the taxon Hallucinigenia had been said to be part of a radiation but itself left no descendants. Part of the genius of the recent insightful discovery is that, despite the organism’s apparent oddities, by using a different perspective (turning it upside down) scientists could connect the organism to some extant populations. Our approach has been to look at the LB1 specimen not upside down but from the outside in. We purposefully have removed discussion of the Liang Bua Cave bones from the exclusively insiders’ perspective that had been used so far by some narrowly trained paleoanthropologists, to broader comparison with biomedical evidence as well, all within in a geological and biogeographic framework. As a result, our group’s research points in the same direction as the findings about Hallucinigenia: despite their diversely unusual aspects, the inhabitants of Liang Bua Cave are related to surviving extant human populations of the region, and are transformed by this broadening of perspective from being a misrepresented, inexplicable alien to a developmentally different person of a very human minority who still walk among us hoping individually for acceptance rather than stigmatization as being so alien as not to be accepted as part of our own species.

 

“Freedom is the right to tell people what they do not want to hear.”

– George Orwell

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Dean Falk’s Flores Circus

By Robert B. Eckhardt

(written for www.LiangBuaCave.org and reposted here and on The Conversation 10 August 2014)

http://www.natureworldnews.com/articles/8395/20140805/hobbit-human-suffering-down-syndrome-researchers.htm

Excerpt from the above link:

“The debate over the origins of LB1 has been going on for about a decade now. Other researchers have posted several rebuttals to claims made by researchers working on the skeletal remains, ‘When this one is refuted, and it will be, then they’ll find something else,’ said Dean Falk of Florida State University and the School for Advanced Research NBC News. ‘It’s good to have people who can be skeptical, but this is turning into a circus.’”

Dr. Falk’s comment seems to have been written as a nonce reaction to news reports about our group’s interpretations of the Liang Bua Cave skeletal remains, because our view differs from hers. The Falkian approach as quoted insists that the findings of anyone who disagrees with the “new species” dogma will of course be refuted. This may happen, of course, because our group accepts that we are dealing with scientific inference rather than divine revelation, but there is a difference between reflexively attacking the authors of scientific papers, vs. assessing the substance of the findings that they have published. In this case Dr. Falk clearly has done the former, which although not surprising, is disappointing. Her insouciant preference for emotions over evidence is signaled by various subtle glosses: The phrase “rebuttals to claims made by researchers working on the skeletal remains” implies that members of our group have not worked with the original materials; our papers make it clear that we have, which Dr. Falk knows very well anyway. Saying that the continuing disagreement over interpretation of the bones “is turning into a circus” is a partially true but peculiarly distorted perspective, like that given by a funhouse mirror that turns one’s perception upside down from reality.

Yes, Virginia, there is a Flores circus. It rolled into view late in October of 2004 with the first two papers published by the group dominated by the Australians Peter Brown and Michael Morwood (sadly, Mike now is deceased; he was a complex, energetic, and interesting person, and is survived by a wife and daughter, both of whom I have met and like; I send them my condolences and wish them well). Back to the circus. As initially represented in contemporaneous and subsequent media reports, the parade was led by a sort of gender dysphoric Snow White being, accompanied by 7 + 6 other little people. The LB1 individual stereotypically is referred to as female but in the earliest reconstruction is depicted as rather hirsute facially, though with skin elsewhere sufficiently glabrous as not to mask prominent male external genitalia; holding the latest mode in magic wand/cudgels; and with a fetching giant dead rat as a combination fur stole/takeout lunch draped fashionably over the left shoulder. The circus menagerie trailing after what later came to be marketed as an “alien from earth” included elephants, great slithery voracious dragons, those giant rats that had managed to survive the hunt, and eventually even hominin-menacing storks. Leading from behind was the bandwagon. Aboard that vehicle were a great many people tricked out as scientists, some with formal academic credentials that had been left behind at the office or lab in the hurry to climb aboard. Not having access to the evidence or time to devote to analysis, most traded snatches of gossip and rumor, employing skills honed during the childhood game of “grapevine.”

I’ll make a brief attempt here to cut from what one wishes were mere satire, to science: LB1 was said by Brown, et al., to be female, but with no detailed, systematic evidence ever presented in support of this guess; our 2006 PNAS paper gives calculations that show LB1 to be male, but on the gracile end of the distribution, as would be entirely consistent with the present human population living in the region. Our current papers provide further data on this point. The specimens originally described in Nature numbered just two, one of which was an isolated tooth. Since then the number of accompanying little people variously has been given from about three to thirteen, with no systematic estimation yet provided of minimum/maximum/probable numbers of individuals whose bones were recovered from Liang Bua Cave. The elephants were stegodons that reportedly grew and shrank with time and inter-island group swims; the “dragons” of course were of the varanid sorts, giant monitor lizards found on Komodo and elsewhere. The large rats often have been said to occur only on islands and thus to be part of the Flores isolation story (now largely abandoned anyway, though still sporadically embraced), but they also occur on New Guinea as well as the Asian, African, and South American mainlands. The South American Giant Rat, Kunsia tomentosus is the largest living rat. The storks were reconstructed to be twice the height of the hominins

[ http://karlshuker.blogspot.com/2014/01/flores-hobbits-and-giant-stork-of-doom.html ]. For a long time no “hobbit” height was too short in the minds of creative writers. Commenting in Science, Jared Diamond used words alone to lop about half a foot (15 centimeters or so) from the originally reported, exaggeratedly short, stature.

For the last decade our group – and a few other groups that deserve mention (those associated with Albert Czarnetzki, Israel Hershkovits, Robert Martin, Ralph Holloway, Charles Oxnard and Peter Obendorf, Gary Richards, come to mind, and I apologize for those that I may have missed) – have been trying to turn the “Hobbit” circus into science.

As we point out in one of our pair of recent papers in PNAS, the approach taken by Falk and her associates has been to attack one or another supposed flaw in each of the attempted diagnoses offered so far to explain what is abnormal about LB1, then to proclaim something on the order of (I paraphrase here) “See! The Hobbit did not suffer from [particular diagnosis], so is normal after all.” This is illogical, and I do not know whether I would prefer that Dr. Falk does or does not realize that her reasoning is faulty. So far, however, this tactic at least has seemed to work on many science writers (though not all – John Noble Wilford is a notable exception, and there are a few others).

Now we are confronting this tactic head on. The first of our recent papers, with the catchy title “Rare events in earth history include the LB1 human skeleton from Flores, Indonesia, as a developmental singularity, not a unique taxon,” makes the point that whatever the specific diagnosis based on its symptoms, LB1 is abnormal. Being abnormal, it cannot be used as the type specimen for a new species.

In our second paper we have made the case for LB1 having Down syndrome. This diagnosis cannot be counted as certain, for the simple reason that material needed to reconstruct a karyotype does not exist; so far recovery of even reliable fragmentary DNA has been elusive. But Down syndrome was diagnosed even before its underlying developmental genetic cause was found to be due to chromosome imbalance in 1956. Those earlier diagnoses were based largely on physical features, as is ours.

Together our two papers provide an elegantly simple unifying explanation for all of the data that have come out of Liang Bua Cave, not requiring multiple subsidiary hypotheses or special pleading. The same cannot be said for the dogma (morphological difference = new species) stereotypically favored by Dr. Falk and many other paleoanthropologists.

To us the uncommon physical characteristics of the LB1 individual do not require exclusion from our species as it existed thousand of years ago on Flores, any more than they would justify rejection of developmentally different people among us now as less than human. Rather, the differences we see in LB1 signal that even in a marginal environment, compassion and mutual aid can be hallmarks of our common humanity that allowed survival of a developmentally unusual individual to adulthood.

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Response to American Scientist Review – Shorter Version

Flores skeletons: Irrational scientists or imaginary species?

Greg Laden reviewed The Fossil Chronicles in the January-February, 2012, American Scientist issue. On July 4, 2012 we submitted a 4100 word response. Subsequently the Editor, David Schoonmaker, allotted 500 words online. Our full critique appears here.

After studying the Liang Bua Cave skeletons in 2005, we were denied further access to what Laden calls “one of the most important finds of the past hundred years.” These bones do not represent a new species, but are important because they spotlight paleoanthropology’s idiosyncrasies.

The Fossil Chronicles recount Dean Falk’s long-running disagreement with Ralph Holloway about the interpretation of fossil hominin endocasts, plus her speculations about the endocast of LB1, the only known skull from Liang Bua Cave. Laden adds further gratuitous disparagement of Ralph Holloway, unacceptably unprofessional in AS.

Laden parrots Falk’s conclusions about these remains: “Homo floresiensis is normal, although very different than expected, just as Taung was different than expected.” But evidence for evolution over two centuries comprises >200 fossil hominin skulls, not two. Some finds were celebrated as ancestors for decades, then rejected later. Piltdown’s fraudulent skull presented the reverse of Taung’s pattern, blocking acceptance of the Dart’s insight for three decades. Ramapithecus beguiled most professionals and students nearly as long, illustrating a “bandwagon effect” in human ancestry reconstruction, among professionals and journalists.

For truth Laden substitutes consensus: “The history of the study of human evolution shows that surprising findings make well-educated and otherwise rational people behave irrationally for a time, until everyone eventually settles on a new view.” Such statements explain the bandwagon effect. Questioning majority view is “irrational,” imposing a penalty with that label, while joining the majority carries easier access to funding and publication, as for “Homo floresiensis” advocates.

Many supposedly “unique” features of LB1 (short stature, low humeral torsion) are shared with other extant humans; others (mandibles lacking external chins, rotated premolar teeth) are common in Flores Rampasasa among extant Australomelanesians, while LB1’s tiny brain, marked asymmetry, and unusually short femora signal developmental abnormality. Our hypothesis, offered in 2006, remains constant: LB1 is an abnormal individual from a relatively recent Flores population. Contradictorily, supporters of “H. floresiensis” originally held that it evolved from H. erectus isolated on Flores over more than 800,000 years, then switched in 2007 to attribute its small brain and short stature to African ancestors a million years before reaching Flores.

The idea that the Liang Bua Cave skeletons represent a new species has – unlike Taung but strikingly like Piltdown and Ramapithecus – decidedly not been a minority viewpoint championed bravely by a few dissidents against widespread opposition. From the first the new diminutive species was a popular, widely romanticised interpretation. Its few critics are held, as by Laden here, to be irrational. This situation will change, but only when there is more general realization that “wrapping events into a good story that supports one’s case” per Sloman’s review in the same AS issue, is alien to the best traditions of science, however appealing to bandwagoneers.

Robert B. Eckhardt, Ph.D.
Professor of Developmental Genetics and Evolutionary Morphology
Department of Kinesiology
University Park, PA 16802 USA

Maciej Henneberg, Ph.D., D.Sc., FAIBiol
Wood Jones Professor of Anthropological and Comparative Anatomy
Medical School
University of Adelaide
Adelaide, SA 5005

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Response to American Scientist Review – Longer Version

Flores skeletons: Irrational scientists or imaginary species?

Robert B. Eckhardt, Ph.D.
Professor of Developmental Genetics and Evolutionary Morphology
Department of Kinesiology
The Pennsylvania State University
University Park, PA 16802 USA

Maciej Henneberg, Ph.D., D.Sc., FAIBiol
Wood Jones Professor of Anthropological and Comparative Anatomy
Medical School
University of Adelaide
Adelaide, SA 5005

Ah, the synergies of the Scientists’ Bookshelf!

Reviewing Thinking, Fast and Slow, Steven Sloman (2012) wrote “In the face of evidence, we are more concerned with how good a story we can tell about it than we are with coming up with alternative accounts to explain it, remembering other events that contradict it, or thinking about how things might have been otherwise…. Wrapping events into a good story that supports one’s case is far more persuasive than poking holes in somebody else’s story or making a fair and balanced argument.” Along the way Sloman notes, almost presciently for the style of the next review, “…that we humans have a tendency to focus only on what is staring us in the face….” Half of the next review essay by Greg Laden (we omit comment on Martin Meredith’s Born in Africa, which is treated in the same piece) focuses rather heavily on two skulls that continue to stare paleoanthropology in the face: Taung, for the better part of a century, and LB1, for the worse portion of nearly a decade.

Since 2004, we and our colleagues (originally several Indonesians, Australians, Polish, and U.S. citizens and British subjects, often referred to as “the pathology group” (probably suggested by the title of the paper by Henneberg and Thorne, 2004), now reduced by the deaths of Teuku Jacob and Alan Thorne but augmented by a growing number of young investigators) have faced much opposition during our efforts at “poking holes in” (we prefer “testing hypotheses about”) the story that Laden and others commonly call “one of the most important finds of the past hundred years.” Several of us (MH, RBE) are among the relatively few scientists to have studied firsthand the skeletons from Liang Bua Cave, Flores. Our study period was limited, and subsequently we have been denied access even to casts since early 2005, despite promises to the contrary. We concur that these bones are important, but not because they represent a new species, which we feel is a misreading of the evidence, a view shared by scientists who are independent of our group (e.g. Martin, et al., 2006). Rather, we stress that the Flores unfossilized remains are of major consequence for a different reason: They provide a chance to scrutinize some key operating assumptions and procedures of an entire sub-discipline, paleoanthropology, that split from human biology in the last century, developing its own methods and ways of arriving at conclusions. We note here that there are some individual scientists working in this domain who observe the rules of evidence and inference that are followed more commonly elsewhere in science. As sometimes is said in such situations, “some of our best friends are” paleoanthropologists, but the field as a whole has methodological idiosyncrasies. If we are successful in catalyzing what we see as overdue disciplinary introspection, the result should be the renaissance of a unified science of human biology, with shared methods used in the study of human populations past as well as present. If we fail to convince our colleagues why this objective is vital, then human biology will remain in its currently fragmented state, with a set of well understood evolutionary principles governing the study of genetic relationships among living populations, while discoveries from the past will continue to flicker briefly as episodic media images illustrating a disjointed narrative that is, for all practical purposes, atheoretical and deeply rooted in ancient Platonic essentialism (Eckhardt, 2007a, Henneberg 2009).

Establishing the necessary common principles that unite the study of human microevolution and macroevolution will require a firm grasp of the difference between nonce explanations reminiscent of Kipling’s “Just So Stories,” and standard tests of hypotheses that take into account the wealth of evidence and principles for its evaluation that have accrued for more than a century. These procedural contrasts parallel distinctions between the blogger and the working scientist. The first might say, as Laden does here, “One wonders, given the reality of the Flores find, whether the world may once have been (partly) populated by additional species as different from the main line of human evolution as Hobbit….” There are many pertinent responses to this statement, of which we will offer only two. First, Laden’s use of word “reality” is misleading. No one questions that real skeletons were found in Liang Bua Cave on Flores in 2003 – indeed, numerous prehistoric human burials have been unearthed on that island since the 1950s (van der Plas, 2002; Villa, et al., 2012); the evolutionary and taxonomic interpretations of the Liang Bua Cave skeletons are in question, not their physical existence. Does Laden take interpretations for “reality”? Second, Laden’s is not even a particularly original speculation about these remains. On January 29, 2007, Karl Zimmer wrote in his blog, The Loom, “To discover a chain of hominid species stretching from the mainland out to Flores would be cool beyond belief. When did the dwarfing begin, one wonders? Was there a Homo sulawesiensis before a Homo floresiensis? Or were the only hominids exploring these tropical islands members of our own species? Here’s hoping 2007 provides some answers.”

The year 2007 passed without the answer hoped for by Zimmer. Indeed, five years later, despite substantial research support provided to the “new species” advocates by the National Geographic Society, The Australian Research Council, and others, we’re still waiting for resolution that does not involve stifling of disagreement. This situation might be remedied if instead of asking about a new data set, not “Wouldn’t it be “cool” if [fill in your own speculation here]…?” but instead “What are some alternative hypotheses about the sample, and how might evidence be used to test them?” (which is, we think, what a Peter Medawar or a Richard Feynman would ask). This is where data, and use of accepted philosophical principles for evaluating those data, come in if one really is doing “zealous research” per the Sigma Xi motto, rather than just trolling for blog hits.

Perhaps by way of establishing his own credentials beyond those of a blogger, Laden notes that he had the opportunity to examine the original Taung fossil under the guidance of Philip Tobias. One of us (MH) in 1990 actually took over from Phillip Tobias headship of the department holding these fossils as well as a profusion of others and for the next five years had an opportunity to familiarize himself with these rich fossil collections as well as to conduct his own excavations in the fossil-bearing region rather than having a passing glimpse of one specimen under the guidance of a respected senior figure in the field. What Laden does not mention, perhaps because he is unaware of the fact, is that Professor Tobias (very recently deceased, a notable loss to the field) was one of the referees who read and supported our group’s paper in PNAS containing the rejection of the putative new species “Homo floresiensis.” Instead, we identified LB1 as a developmentally abnormal (e.g. unusually asymmetrical craniofacially, with femora strikingly short, straight and tubulated, etc.) individual member of a modern Australomelanesian population with multiple characteristics (gnathic, dental, postcranial) that are found routinely among populations in its region, including people (the Rampasasa) still living near the cave (Jacob, et al., 2006). Phillip Tobias also wrote an enthusiastically supportive introduction to our last book on the subject of Flores finds (Henneberg, Eckhardt, Schofield 2010).

What about Laden’s qualifications to express an opinion about this problem in human evolution, implied in his use by The American Scientist as a reviewer? He hints at inside knowledge of the field, as by the statement “I thought that I had already heard all of the scuttlebutt….” However, there is a lot more to interpreting evidence responsibly, which is more important in science than familiarity with rumor and innuendo. For example, one wonders how extensive was his examination of the Taung fossil. Laden states “Taung’s brain and teeth were more apelike…but Taung’s body was more humanlike in that it was apparently configured for upright walking.” Really? What body? The Taung find comprises much of the face and mandible plus a partial brain endocast – but no postcranial remains, i.e. no “body.” Raymond Dart’s prescient interpretation of upright posture for Taung was all the more brilliant and intellectually courageous for its being an inference from Taung’s extremely limited craniofacial remains. Actual postcranial remains of australopithecines were decades in coming to confirm his insightful extrapolation (and never have been found for Taung). Evidence and inference both are important, but they are not the same. Laden’s failures to distinguish among data, reasoning, and rumor (“scuttlebutt”) seriously flaw his review. We suspect that Meave Leakey might agree with us about his familiarity with the field after her complexion loses its light purple hue (“Mauve” to Laden).

So much for Laden’s reliability as a reviewer. What of his main conclusions about The Fossil Chronicles? Falk’s selective autobiographical volume has two quasi-related foci: a long-running controversy, chiefly with Ralph Holloway, about the interpretation of fossil hominin endocasts, and her opinions on the Flores skeletons. Any reviewer of the book could choose from a wide array of perspectives. Among various alternatives, she or he could summarize these topics neutrally, or provide an independent perspective based on additional evidence, or offer informed criticism of the author’s potentially subjective positions. Laden does none of these; instead he simply echoes Falk’s viewpoints on both subjects. His biases, as Falk’s, are set forth clearly. “The academic fight between Holloway and Falk was typical of the 1980s. Falk was a woman working in a largely male field, and some people wondered whether Holloway might be trying to marginalize her for that reason…. Anyone interested in a study of both gender bias and the ad hominem argument would do well to look at these papers.” To those statements we would reply: Many people may wonder about many things, but unsupported conjecture doesn’t – at least shouldn’t – count for anything in science in general, or in The American Scientist in particular. Nowhere in Laden’s review does he present any evidence in support of his serious professional disparagement of Ralph Holloway, unless one counts his own unpublished grad school term papers to which he alludes. We had thought that Sigma Xi’s motto was “Companions in zealous research,” not something more like “collaborators in undocumented defamation.” In a journal published by our Society one might have expected not innuendo, but evidence (though we have been here before: see Eckhardt, 2007b, 2007c). There are plenty of data that bear on this point, allowing investigators to get beyond the superficially journalistic approach of “He said, she said.” For interested readers, here are two papers among many that can be referenced, one published before Laden’s review (Vannucci, Barron, and Holloway, 2011), the other after (Holloway, 2012).

Just as Laden echoes Falk’s opinion of Holloway’s endocast research, so does he repeat uncritically her conclusions about the Flores remains, even to the specific arguments in support of their status as a new species of human. “Because the female Hobbit and the fossils found with her are so unusual, it has been suggested that their peculiarities are attributable to some disease or abnormality, such as microcephaly. Homo floresiensis is normal, although very different than [sic: from] expected, just as Taung was different than [sic: from] expected.” Who is supposed to have expected what about the Flores remains, and why?

In terms of formal logic, argument by analogy, as with Falk and Laden extrapolating from the reception of Taung to that of the Flores skeletons, is an instance of reasoning from the particular to the particular. A problem here is that in the reconstruction of human evolution, the data set has become so large that there are not merely two particulars for evaluation, but a great many. As drawn by Laden, comparison is simply between two skulls, Taung and LB1 (since the LB1 specimen has the only known cranium from Liang Bua Cave). They lived about 2 million years apart on two different continents. At about 400 ml the LB1 endocranial volume is only about one-third the average in normal extant humans, but whether it is microcephalic or not depends on the reference population, which is part of the matter at issue. As far as the argument from one particular specimen to another particular specimen, some context is necessary to avoid analyses that are simplistic, as are those of Falk and Laden. Over the nearly two centuries that human fossils have been accepted, thousands of specimens have been recovered (the numbers differing depending on how one counts fragmentary and partial finds and the temporal and taxonomic boundaries that are used, but one can say that some 210 fossil hominin skulls are known well enough to reconstruct brain sizes (Henneberg and Saniotis 2009, Saniotis and Henneberg 2011). Throughout this time the skulls have occasioned much discussion and debate on various grounds. Comparing the reception of just two skulls, in the presence of a hundredfold more that appear to be deliberately ignored by people claiming familiarity with the field, may at best suggest a bias.

There is some truth to the contention that novel discoveries sometimes are resisted (for documentation of this point see Eckhardt, 2000, particularly the chapter titled “A century of fossils”). However, resistance does not always occur because the new find is held to be pathological. Taung was dismissed by Sir Arthur Keith and others as a human ancestor, though on other (quite specious) grounds than pathology. Similarly, Keith excluded the earliest known fossils of Javan pithecanthropines from human ancestry because they were, in his chronology, too primitive and too recent to qualify as ancestors. Although Rudolf Virchow and others did hold that the Neanderthal remains discovered decades earlier were those of a modern human afflicted with arthritis, rickets and syphilis, the previous earlier description, by Fuhlrott and Schaffhausen, held them to be normal, and Thomas Huxley championed them as ancestors of extant humans. Schaffhausen and Huxley have been proven correct. In other cases, diagnoses of morphology-altering pathology have been substantiated, notably without the specimen in question being proposed as the type specimen of a new human species (Walker, et al., 1982).

It also should not be overlooked that some finds have been acclaimed widely as ancestral humans for decades, only to be rejected much later because the evidence eventually failed to stand up to close scrutiny. Piltdown, mentioned by Laden, is a well known example; its fraudulently fabricated physiognomy was the reverse of Taung’s total morphological pattern, thereby constituting a barrier to acceptance of the Dart’s evidence and reasoning. Another unfortunate example, seemingly rooted in wishful thinking rather than fraud, was Ramapithecus. This taxon, which was advocated as a hominid by Elwyn Simons (1961), misled most professionals and, by becoming standard textbook fare, students as well for about two decades. The error persisted even though its status was based on very little physical evidence, was at variance with growing molecular data, and was separated from the otherwise earliest known humans, australopithecines, by a gap of about ten million years. Examples as disparate as Piltdown and Ramapithecus share a common element: they illustrate the episodic occurrence of a “bandwagon effect” in the reconstruction of human ancestry, with many professionals who have little knowledge of the evidence wishing not to be seen as lagging behind the latest intellectual fashion wave. My favorite firsthand example of this phenomenon was a conversation that I had several years ago at a professional meeting with an anthropologist who is a member of the National Academy of Sciences. I had expressed strong doubts that the Liang Bua Cave skeletons represented a new human species, noting that nearly all of the supposedly defining features of the new taxon were based on the single skull that existed. Her reaction was to insist that I had to be wrong because there were multiple skulls, all sharing the same distinctive anatomy. She knew, because she had been teaching about the find. Chivalry prevents me from identifying this person, but perhaps we can add the incident to the undocumented scuttlebutt of this colorful field, since that seems acceptable in the context of The American Scientist.

What protects scientific disciplines against manifestly erroneous examples of the sort discussed here? Laden seems to rely for validation on consensus, without any discussion of how widespread agreement might be reached other than spontaneous disappearance of the mental illness of a minority: “The history of the study of human evolution shows that surprising findings make well-educated and otherwise rational people behave irrationally for a time, until everyone eventually settles on a new view.” Statements of this sort in fact help us to understand why there is a bandwagon effect: The implication that scientists who do not accept the new view are irrational. The “irrationality” label carries a price to those onto whom it is pinned. Just seeming to be with the majority can carry more ready access to funding and publication, as has been the case so far for the advocates of “Homo floresiensis.”

Are there reasonable criteria for judging the intrinsic correctness of hypotheses other than popularity? Sure. One is the principle commonly attributed to Carl Sagan that “extraordinary claims require extraordinary evidence” (which is an updated version of Hume’s Maxim). But of course this principle raises another question: Which of several not very likely possibilities is the more extraordinary claim? This question lies at the heart of the continuing controversy surrounding the skeletons from Liang Bua Cave: Do they all uniformly represent an entirely new, hitherto unknown human species or is there evidence that the sample might include one or more unusual members of our own?

Experienced scientists and philosophers of science know that the system of data collection and analysis in which we operate is not one that, particularly in unusual situations, inevitably yields correct answers (by which we mean those that are in accord with how nature has operated in the past and continues to operate, to make a complex matter simpler than it sometimes is), particularly in the short run (Dart waited three decades for vindication). Again, however, there are operating principles that furnish some guidelines. One is the hallowed “Occam’s Razor.” Here I am paraphrasing and summarizing several cogent presentations readily available on Wikipedia (re Occam’s Razor) and Skeptico (re Burden of Proof). In principle Occam’s Razor commonly is taken to mean that, other things being equal, a simpler explanation is preferable to a more complex one; realistically, in practice one seeks the simplest explanation that does not reduce the explanatory power of a hypothesis. Of critical importance but often overlooked is the principle that the implicit burden of proof is on the person asserting the claim (in this case, that the Liang Bua Cave skeletons represent a new species). When this principle is violated the consequence is that the burden of proof is shifted unfairly to critics of the claim. This shift introduces yet another logical fallacy — that a proposition is true if it has not yet been proven false. In the case of the Flores skeletons Bertrand Russell’s version of Occam’s Razor is particularly apposite: “Whenever possible, substitute constructions out of known entities for inferences to unknown entities.” It seems that, paradoxically for how science is thought to operate, some very bizarre aspects of the “new species” interpretation have heightened interest in it rather than raising appropriate skepticism. Situations of this sort are compounded further if attempts at hypothesis testing are impeded by restricting access by the critics to the primary data whose interpretation is in question, as demonstrably is the case here. A notable parallel case in physics recently was documented tellingly by Eugenie Samuel Reich in Plastic Fantastic (2009). Instances of this sort occur when, in the face of astonishing and exciting claims (the sort that inspire phrases such as “Wouldn’t it be cool if…) critical judgment is suspended by journal editors who exchange their appropriate roles as gatekeepers for the more glamorous ones of advocate and promoter.

Against this background, we see the “Liang Bua Cave skeletons” controversy as being a perfect scientific storm that brings together several winds, each of gale force:
1. Disregard for data. Many of the supposedly “unique” features of the supposed new species (very short stature, low humeral torsion, etc.) are not unique to the Liang Bua Cave skeletons at all, but occur, individually and in combination, in other extant human populations, others (e.g. mandibles lacking external chins, rotated premolar teeth) are notably common in extant Australomelanesians, including the nearby Rampasasa, while the tiny (400 ml) endocranial volume, abnormal asymmetry, and unusually short femora of LB1 offer evidence of individual developmental abnormality. Published data disproving the supposedly unique features are not addressed, while illustration of asymmetry and other abnormality has been denied, thereby going beyond the negative phenomenon of shifting the burden of proof, to patently ignoring documented disproof. This aspect of the problem further concerns the predictive value of hypotheses.
2. Indifference to hypothesis formulation and testing. Our group’s hypothesis (Jacob, et al., 2006) has remained unchanged from the beginning of our work on this problem (LB1 is an abnormal individual member of the expected modern human regional Australomelanesian population still represented on Flores). In contrast, supporters of the new taxon not only have multiplied hypotheses, but the original one (the new species evolved in isolation on Flores over more than 800,000 years from a Homo erectus ancestor) was changed in 2007 (to hold that the new species evolved its small brain and short stature before reaching Flores, and is derived from an African taxon that lived more than a million years earlier, at the pre-erectus level, sharing a common ancestor with Homo habilis). These formulations appear to us as mutually exclusive, but the contradictions do not appear to yet have been either reconciled by the proponents of the new species or the difficulty commented on by science writers and other journalists.
Our hypothesis originally was formulated in response to the data known at the time of the discovery. Subsequently, Berger, et al. (2008) described a sample of relatively recent (about 940 to 2890 years bp) small-bodied human skeletons from Palau, combining relatively short stature with reduced or absent external bony chins, but with all known partial crania being around the low end of the distribution of small-bodied humans (very roughly, about 1200 ml). Thus, for example, absence of an external bony chin manifestly is not necessarily primitive or even unusual, while on the other hand a single endocranial volume of about 400 ml (LB1) falls outside the normal range for another relatively recent small-statured human population from the same geographic and cultural area that includes Flores. The response to the Palau find from supporters of the view that the Liang Bua Cave remains must represent a new species is not data analysis but denial: “There’s nothing new about these little guys; … this offers zero window into Homo floresiensis…” (W. Jungers, quoted in Culotta, 2008). Jungers’ response echoes uncannily the trope often used by police officers at crime scenes: “Move along, there’s nothing to see here.”
3. Preference for myth over method. “Unknown entities” in the sense advised against by Bertrand Russell abound in the widely but uncritically accepted new species hypothesis. In fact the supposedly inexplicable elements are emphasized, to the obvious delight of journalists, most of whom have no notable scientific background. Particular examples of this gambit can be seen in the PBS special titled “Alien from Earth.”

We close by noting that from the first publications in 2004 through the present time, the idea that the Liang Bua Cave remains represent a new species has – unlike Taung but like Piltdown and Ramapithecus – decidedly not been a minority viewpoint championed bravely by a few scientific pioneers against widespread opposition. Instead, from the first the new diminutive species was a popular, widely accepted interpretation (which, like the hominid status of Ramapithecus, already has entered the textbooks). Its relatively few critics, in contrast, are held, as by Laden here, to be irrational. It is our position that this situation will change, but only if there is more general realization that the approach of “wrapping events into a good story that supports one’s case is far more persuasive than poking holes in somebody else’s story” is alien to the best traditions of science, however appealing to journalists. We hope that we will not be characterized as irrational for as long a period as was Raymond Dart (roughly three decades; we’re already up to year eight) but find that situation, however difficult, is preferable to joining a broad consensus that has coalesced prematurely and for the wrong reasons. To quote Sloman in closing as in opening, isn’t it time for “a fair and balanced argument”?

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