Post-Cranial Skeletons of Hypothyroid Cretins Show a Similar Anatomical Mosaic as Homo floresiensis

Abstract

Human remains, some as recent as 15 thousand years, from Liang Bua (LB) on the Indonesian island of Flores have been attributed to a new species, Homo floresiensis. The definition includes a mosaic of features, some like modern humans (hence derived: genus Homo), some like modern apes and australopithecines (hence primitive: not species sapiens), and some unique (hence new species: floresiensis). Conversely, because only modern humans (H. sapiens) are known in this region in the last 40 thousand years, these individuals have also been suggested to be genetic human dwarfs. Such dwarfs resemble small humans and do not show the mosaic combination of the most complete individuals, LB1 and LB6, so this idea has been largely dismissed. We have previously shown that some features of the cranium of hypothyroid cretins are like those of LB1. Here we examine cretin postcrania to see if they show anatomical mosaics like H. floresiensis. We find that hypothyroid cretins share at least 10 postcranial features with Homo floresiensis and unaffected humans not found in apes (or australopithecines when materials permit). They share with H. floresiensis, modern apes and australopithecines at least 11 postcranial features not found in unaffected humans. They share with H. floresiensis, at least 8 features not found in apes, australopithecines or unaffected humans. Sixteen features can be rendered metrically and multivariate analyses demonstrate that H. floresiensis co-locates with cretins, both being markedly separate from humans and chimpanzees (P<0.001: from analysis of similarity (ANOSIM) over all variables, ANOSIM, global R>0.999). We therefore conclude that LB1 and LB6, at least, are, most likely, endemic cretins from a population of unaffected Homo sapiens. This is consistent with recent hypothyroid endemic cretinism throughout Indonesia, including the nearby island of Bali.

More on the Liang Bua finds and modern human cretins

“…Brown and Maeda, 2009;Jungers et al, 2009a,b;Larson et al, 2009;Moore et al, 2009;Morwood and Jungers, 2009); and are therefore available to us. These data greatly strengthen our views (Oxnard et al, 2010). We are surprised, therefore, that Brown does not cite our recent work, especially as he does refer to other papers of the same and later dates that he uses to deny the cretinism hypothesis (e.g.…”

“…Brown's comments refer, among others, to (1) delayed growth and development indicated by unfused epiphyses, (2) postcranial limb proportions: limbs to trunk, between limbs, and within limbs, (3) postcranial bone torsions and angles, (4) postcranial robusticity, real and apparent, (5) skull features, and (6) cretinism on Flores. In each of these areas, much information about cretins is incorrect and much information (Oxnard et al, 2010) comparing the Liang Bua remains with cretins is ignored. …”

Craniometric ratios of microcephaly and LB1,Homo floresiensis, using MRI and endocasts

“…Indeed, the overall morphology of LB1 and her kin combine traits that extend from Australopithecus through to modern H. sapiens, a truly unique and somewhat confusing pattern not shared by any other extinct or living hominin population (but see ref. 24 for discussion of hypothyroid endemic cretinism in relation to LB1's postcranial bones).…”

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“…288-1 has long begged an explanation, given that it lies so far beyond the human range of variation (in the current study its index value [85.6] falls over 6 standard deviations above the recent human mean), while at the same time falling far short of African ape ranges of variation (here, for example, its value lies 5 standard deviations below the chimpanzee mean). The more recent discovery of the holotype of Homo floresiensis (LB1) with a nearly identical index value (87.8, which in this study falls 7 standard deviations above the modern human mean, and some 4 standard deviations below the chimpanzee mean) has been of even greater importance because while LB1's exact taxonomic assignation is uncertain (Argue et al, 2006;Conroy and Smith, 2007;Falk et al, 2007;Gordon et al, 2008;Hershkovitz et al, 2007;Jacob et al, 2006;Martin et al, 2006;Morwood et al, 2005;Obendorf et al, 2008;Oxnard et al, 2010;Tocheri et al, 2007;Vannucci et al, 2011), whatever the specimen's ultimate taxonomic "fate," it clearly belongs within the genus Homo. This indicates that not only do high humero-femoral indices have great antiquity among the Hominini in general, but were also very likely plesiomorphic for the genus Homo as well (Hartwig-Scherer and Martin, 1991;Holliday, n.d.).…”