Getting Desperate

by
Colin Groves

Dr. Colin Groves is a paleoanthropologist and Professor of Biological Anthropology at the Australian National University.
This article is a response to an article by Answers in Genesis, which was itself a response to the article Up from the Apes published in Time on August 23, 1999.

Answers in Genesis must be getting desperate. They have been sniping away at evolution for over twenty years now, and the scientific community remains unmoved. Serious periodicals like Time and Newsweek likewise continue to give science preference over pseudoscience. The Time article, Up From The Apes shows why: scientific understanding progresses as new discoveries are made, whereas pseudoscience stands still, forever beating the same drum.

They begin by misunderstanding the difference between science and its popular reporting:

In reality, there is actually little new in this article. What is new is trivial, and does not establish human evolution, any more than similar claims (now mostly discredited) did so in the past.

Of course! Articles in Time are not written to "establish human evolution". They are written to disseminate news about progress in science. To find out what is the evidence for human evolution, you have to read whole books with sustained arguments: I don't mean popular books by Richard Leakey or Don Johanson, but full-on textbooks such as are used in second/third year university courses. As for finding out what is new in palaeoanthropology, you must read the original articles in Nature, Science, PNAS or elsewhere.

AiG continue:

The article papers over the profound disagreements amongst evolutionists themselves about the significance of the various claims. For example, Ardipithecus ramidus is proudly portrayed as our ancestor closest to the apes. When the evidence is examined, it is found most wanting, especially when it is remembered that it was claimed as THE missing link at the time it was announced to the eager media. The bits and pieces were found scattered over about a mile and put together to get 'the missing link'.

Yes and no, though mostly no. Most of the material (teeth, many of them associated, a skull fragment, a hemimandible and a humerus) was found at a single locality, and of the rest the associated arm bones and the associated skull fragments were found at two others (WoldeGabriel et al., 1994, Fig.1).

Next, we have an example of the lack of understanding of biological taxonomy and of the rules of nomenclature:

Homo habilis is now widely recognized as a mixture of different types, technically called an "invalid taxon".

The term "invalid" carries the implication that the taxon concerned is a junior synonym of some other taxon. Every species has, or should have, a type specimen, so only if the type specimen of Homo habilis (which is Olduvai Hominid 7, or OH7 for short) is found to belong to some other species does the name Homo habilis lapse into synonymy. In the present case, it has been proposed (Groves, 1989) and widely accepted (Wood, 1992 and elsewhere; Kramer et al., 1995; Strait et al., 1997), though not universally (Miller, 1991; Tobias, 1991), that the fossils that had been ascribed to the species Homo habilis should actually be partitioned among (at least?) two separate species. The one to which OH7 belongs is automatically to be called Homo habilis; the other, typified by the famous Lake Turkana skull, ER 1470, is called Homo rudolfensis.

AiG go on to reveal how unfamiliar with the naming and morphology of fossil hominin specimens they are:

Skulls 9,11,12,13,14 and 15 are all just variations of the true human kind.

One never simply refers to "skulls 9,11, ..." etc. Fossils (which are not necessarily skulls, of course) are numbered by their site of discovery. It is clear from the context that these are Olduvai specimens, not from Koobi Fora, Omo Shungura, Hadar, Sangiran, Skhul, or some other site, so they should have been referred to as "OH9, 11, ..." etc. I will take these specimens in turn:

OH9 is a calvaria, that is, the major portion of a braincase. It is low and angular, and the brow ridges are enormous, the largest known on any fossil hominin. When discovered, it was commonly regarded as an African specimen of Homo erectus, but it falls way outside the range of variation of that species. So far, it is one of a kind. It most certainly is not a variation of "the true human kind", if by that is meant Homo sapiens; all one can say is that it does belong to the genus Homo. Incidentally, I can't see why it is in the list ("Skulls 9 ..." etc.) above, as at no time has it ever been considered a member of Homo habilis.

OH11 is just a palate and maxillary arch. It has not been fully described in the literature. Tobias (1991) classes it as Homo erectus without discussion.

OH12 is a partial calvaria with associated maxillary fragment. It has a very small cranial capacity (727cc) but thick cranial walls. Again, Tobias (1991) refers it to Homo erectus.

OH13 is a partial skull, with braincase, palate and both upper and lower teeth. It is a specimen of Homo habilis, with a cranial capacity of 673cc. (Tobias, 1991).

OH14 is a very fragmentary cranial vault of a juvenile Homo habilis.

OH15 is a small collection of Homo habilis teeth.

The list therefore contains some substantial specimens (OH9, 12 and 13), which are all way, way outside the morphological range of variation of modern humans, as well as some pretty insubstantial ones (OH11, 14 and 15) which I have not seen, and I bet no-one in AiG has seen -- at any rate, if AiG have any evidence to dispute Tobias's assessments of them, then they are not letting on.

Then they trot out the same old assertions they always do about australopithecine locomotion:

Various respected evolutionists have provided evidence that Australopithecus spp. (pictures 2-8) did not walk upright, certainly not in anything like the human manner (e.g. Oxnard on anatomy,1 Spoor on inner ear balance organ structure2), and are not transitional between apes and people. This is totally left aside by the article. There is no reason to connect the australopithecines to humans, except in the belief system of evolutionists.

Reference 1 is to Oxnard (1975, 1984), and ref. 2 is to Spoor et al. [sic; not just "Spoor"] (1994). Poor Charles Oxnard finds himself quoted, much to his dismay, in every single creationist piece on human evolution, without exception. At least the present AiG writers have not stooped to quoting Zuckerman, who has hitherto been the other anatomist that creationists have deigned to acknowledge as an expert on human evolution; but they have not come to terms with Oxnard's own evolving views, and continue to cite him as if he still thought the same as he did 15 years ago or more. In a small teaching resource booklet, which to my knowledge is his latest written opinion on the matter (Oxnard, 1991:30-31), he first gives the basic data on australopithecine postcranial anatomy, then discusses possible functional interpretations, and finally comes to what it means for human evolution. He puts forward four scenarios: it could be (1) mosaic evolution (not all parts evolved at the same rate), or (2) parallel evolution (bipedality evolved more than once from closely related ancestors), or (3) convergent evolution (bipedality evolved quite independently, from quadrupedal ancestors), or (4) the australopithecines could be unrelated to human evolution at all. His preferred option is a combination of mosaicism and parallelism. Creationists should notice that Oxnard rejects option 4 out of hand, and they should stop quoting him as if he supports it.

The reference to Spoor et al. (1994) is ingenuous. What AiG missed in that paper is -- well, they obviously missed the entire message of it, but the implication which Spoor et al. draw for australopithecine locomotion is encapsulated in a statement on p.648,

These observations support studies of the postcranial fossil record which have concluded that H. erectus was an obligatory biped, whereas A. africanus showed a locomotor repertoire comprising facultative bipedalism as well as arboreal climbing.

The background to this is that there are two schools of thought about australopithecine locomotion. One school holds that as well as being bipedal they retained considerable climbing ability (McHenry, 1986, 1992, 1994; Stern & Susman, 1991; Duncan et al., 1994; Berger & Tobias, 1996; Berge, 1998; Macchiarelli et al., 1999); the other sees the powerful arms and funnel-shaped thorax as primitive retentions, and argue that australopithecines were obligate terrestrial bipeds (White & Suwa, 1987; Lovejoy, 1988; Latimer, 1991; Tuttle et al., 1991; Gebo, 1996; Ohman et al., 1997). Some French authorities see the australopithecine sample as falling into two groups (facultative arboreal and obligate terrestrial), with intermediates between them (Senut & Tardieu, 1985; Senut, 1991; Bacon & Baylac, 1995). I am nowadays more convinced than I formerly was by the arguments of the "obligate terrestrial school"; for example Latimer (1991) lists quite a number of features of the lower limb that resemble the human condition and no other, such as that the hallux (big toe) of A. afarensis is not abductable as would be required for grasping.

This list of authors on australopithecine locomotion is very far from exhaustive. None of them expresses any opinion remotely resembling those attributed to Oxnard and to Spoor et al. by AiG: not even Oxnard or Spoor et al. themselves. There is no reason not to connect the australopithecines to humans, except in the belief system of creationists.

The final sentence in the AiG article is pure fantasy:

When complete fossils are found, they are easy to assign clearly as either 'ape' or human⁽¹⁾, there are only 'ape-men' where imagination colored by belief in evolution is applied to fragmented bits and pieces.

What do they mean by "complete"? There are of course many fragments for which one would wish to propose an identification only after the most painstaking study, and even then perhaps only tentatively; these would include OH11, 14 and 15, which the AiG article so glibly claims as "the true human kind". There are also very many which, though in different states of completeness, none the less all possess perfectly diagnostic traits of some described species or other. "Ape-men" disappear only where imagination colored by belief in special creation is applied, whether to well-preserved skulls or postcranial bones, or to what AiG are pleased to dub "fragmented bits and pieces".

1. View the table on the skull comparison page, which demonstrates that creationists actually find it not 'easy', but horribly difficult to classify fossils as ape or human. If we compare five of the most important creationist writers on humans origins (Gish, Lubenow, Bowden, Cuozzo and Mehlert), no two of them agree on how to classify some of the most well-known fossils. In fact, AIG's favored expert on human evolution, Marvin Lubenow, assigns OH 13 (one of the fossils AIG says is just a variation of the true human kind) to the australopithecines! So much for 'easy to assign'. - JF

References

Bacon, A-M. & M. Baylac. 1995. C.R.Acad.Sci.Paris (series IIA), 321:553-560.

Berge, C. 1998. AJPA, 105:441-459.

Berger, L. R. & Tobias, P. V. 1996. JHE, 30:343-348.

Duncan, A. S., J. Kappelman & L. J. Shapiro. 1994. AJPA, 93:67-81.

Gebo, D. L. 1996. AJPA, 101:55-92.

Groves, C.P. 1989. A Theory of Human and Primate Evolution. Oxford University Press.

Kramer, A., S. M. Donnelly, J. H. Kidder, S. D. Ousley & S. M. Olah. 1995. JHE, 29:443-462.

Latimer, B. M. 1991. In (Y. Coppens & B. Senut, eds.) Origine(s) de la Bipоie chez les Hominidэ, 169-176. CNRS, Paris.

Lovejoy, C.O. 1988. Sci. Amer. 259:118-125.

McHenry, H. M. 1986. JHE, 15:177-191. 1992. AJPA, 87:407-431. 1994. In (R. S. Corruccini & R. L. Ciochon, eds.) Integrative Paths to the Past, 251-268. Prentice-Hall.

Macchiarelli, R., L. Bondioli, V. Galichon & P. V. Tobias. 1999. JHE, 36:211-232.

Miller, J.M.A. 1991. AJPA, 84:385-398.

Ohman, J. C., T. J. Krochta, C. O. Lovejoy, R. P. Mensforth & B. Latimer. 1997. AJPA, 104:117-131.

Oxnard, C.E. 1975. Nature 258:389-395. 1984. The Order of Man. Yale University Press.

Oxnard, C.E. 1991. Human Fossils: Thinking about the Evidence. University of Western Australia: Centre for Human Biology Resource Paper no.1.

Senut, B. 1991. In (Y. Coppens & B. Senut, eds.) Origine(s) de la Bipоie chez les Hominidэ, 245-257. CNRS, Paris.

Senut, B. & C. Tardieu. 1985. In (E. Delson, ed.) Ancestors: the Hard Evidence, 193-201. Alan R. Liss, New York.

Spoor, F., B. Wood and F. Zonneveld. 1994. Nature 369:645-648.

Stern, J. T. & R. L. Susman. 1991. In (Y. Coppens & B. Senut, eds.) Origine(s) de la Bipоie chez les Hominidэ, 99-111. CNRS, Paris.

Strait, D.S., F.E.Grine & M.A.Moniz. 1997. JHE, 32:17-82.

Tobias, P.V. 1991. Olduvai Gorge, Vol.4: The Skulls, Endocasts and Teeth of Homo habilis. Cambridge University Press.

Tuttle, R. H., D. M. Webb & N. I. Tuttle. 1991. In (Y. Coppens & B. Senut, eds.) Origine(s) de la Bipоie chez les Hominidэ, 187-198. CNRS, Paris.

White, T. D. & G. Suwa. 1987. AJPA, 72:485-514.

WoldeGabriel, G., T.D.White, G.Suwa, P.Renne, J.de Heinzelin, W.K.Hart & G.Heiken. 1994. Nature, 371:330-333.

PNAS -- Proceedings of the National Academy of Sciences of the USA
AJPA -- American Journal of Physical Anthropology
C.R.Acad.Sci.Paris -- Comptes Rendus de l'Acadчie des Sciences, Paris
JHE -- Journal of Human Evolution
Sci. Amer. -- Scientific American

This page is part of the Fossil Hominids FAQ at the talk.origins Archive.

Getting Desperate

byColin Groves

References

by
Colin Groves