Creationist Arguments: Response to Jon Scott

The Hominoid Homepage by Jon Scott appears to have been written partly in response to my own Fossil Hominids pages. Here is my response to Scott and some of the claims in his pages.

Ramapithecus

As Scott correctly states, Ramapithecus was considered a hominid for a while, before more complete fossils showed it to be very similar to orang-utans. But then he goes on to make some confusing and seemingly contradictory statements, sometimes seeming to agree with the current evolutionary consensus that Ramapithecus was related (and probably ancestral) to modern orang-utans, at other times stating (incorrectly) that it is considered to be ancestral to chimps, gorillas and humans.

Australopithecus

Lucy (AL 288-1): Scott claims that Lucy was not capable of bipedality and may have been a knuckle walker. This is totally unsupportable. I know of no scientist who has ever studied Lucy and concluded that she was not bipedal (which is not to deny that she may also have been arboreal). For example, McHenry (1986) points out that the feet, knees, legs and pelvises of australopithecines are strongly adapted to bipedality, while the hands and wrists show no adaptations to knuckle walking or any other form of quadrupedality. (More recently, Richmond and Strait (2000) did find evidence of a trait associated with knucklewalking in Lucy's wrist, but they still believe she was bipedal.)

Scott's only evidence for non-bipedality is that "They lacked the stabalizing tubercles in their heels necessary for long-term erect posture" (Howells 1993). However to claim this shows that Lucy was not bipedal badly misrepresents Howells, who is emphatic that Lucy was most definitely bipedal:

"The Afar hominids were unquestionably erect: their pelves, spines, and knees show it."

"In any case, the Laetoli-Afar creatures were clearly erect-walking australopithecines." (Howells 1993)

I would like to know why Scott (who I would bet does not even know what "stabilizing tubercles" are) thinks they are necessary for erect posture, when his source (who does know what they are) clearly disagrees.

Sts 14: Scott claims the bones of Sts 14 show it to have been a knuckle walker. How was this determined from a pelvis, femur, ribs and vertebrae, especially in light of the fact that scientists overwhelmingly find them to be convincing evidence of bipedality?

Scott claims that some australopithecines "appear to be 100% chimpanzee, others 100% orangutan, ...". These claims are based on quotes by Oxnard (1975) and Zihlman (Herbert 1983) which are commonly seen in creationist collections of out-of-context quotes. While these authors do claim some similarities with orang-utans and chimps respectively, their papers do not say that they were 100% orang-utan or chimpanzee, and in fact disprove any such assertion.

Finally, Richard Leakey has never claimed australopithecines were brachiators (Scott might want to look up the meaning of that word, since it does not mean what he seems to think it means), nor does he deny that they were bipeds. Leakey (1994) states that Lucy "undoubtedly was a biped".

Homo habilis

Scott claims that "The first 'homo habilis' specimen ever discovered was actually zinjanthropus ...". This claim is taken from an article by creationist David Menton. It is incorrect. Although H. habilis was discovered one year later and in the same place as Zinjanthropus (now Australopithecus boisei), the two species are quite different, and no A. boisei skull has ever been classified as H. habilis or vice versa.

Scott claims that most habilis specimens had a sagittal crest even larger than most australopithecines. This is clearly wrong, as the four habilis illustrations further down the page show no crests, large or small. A reference for this claim links to a (now disappeared) web page, but this page makes no mention of sagittal crests, and the photos of habilis skulls shown there are again totally lacking in crests.

According to Scott, the H. habilis brain was "generally only about 550 cc, like chimpanzees". 550 cc is actually above the maximum chimp brain size of about 500 cc, and it is by no means typical of habilis. One habilis specimen is less than 550 cc; about half a dozen others range from about 590 cc to 750+ cc.

Scott says that ER 1470's brain size of 750 cc is smaller than a gorilla, and "well within the limits of today's apes". Even if this was true, it is hardly valid to compare a small creature like habilis with male gorillas many times larger. However, it is false. The largest gorilla ever cited was 752 cc, but Holloway has questioned this figure after being unable to find the skull. If this individual is excluded, male gorillas seem to top out at about 700 cc. (Holloway, 1996)

Homo erectus

Here is one of Scott's most amazing claims, namely that some H. erectus specimens were actually a subspecies of modern humans, called Homo sapiens giganticus by Scott, which grew up to 12 feet tall.

Scott says that the size of the female H. erectus skull ER 3733 indicates that she was about six feet tall. I find it hard to believe that skull size correlates well enough with body size to provide any useful information, and I am not aware of any fossil, including ER 3733, having its height estimated from skull size. What is the reference for this?

The text for Scott's description of the Turkana Boy fossil was taken from my web page with only minimal changes. But where my page states that the skull had a size of 880 cc and an estimated adult size of 910 cc, Scott has modified that to an estimated adult size of 1000 cc. On what evidence? My figure was taken from the definitive work on the Turkana Boy skeleton (Walker and Leakey 1993). Similarly, he claims that the boy was only 8 or 9, even though my material gave his age as 11 or 12 (based on comparison with modern boys, but possibly only 9 chronologically if H. erectus matured faster than modern humans). And Scott originally stated that the fossil's height was "OVER six feet tall", even though my page had said that the fossil was 5'3" tall, and would have been about 6'1" as an adult (again, based on Walker and Leakey). Scott has since modified this to say that the skeleton was "nearly 6 feet tall", which while not as blatantly false, is still misleading (I doubt many people consider 5'3" to be "nearly 6 feet tall").

Scott estimates that the Turkana Boy would have been 10 or 12 ft tall as an adult. This figure is absurd, and unsupported by any direct fossil evidence. It is obtained by exaggerating the height upwards, exaggerating the age downwards, comparing the Turkana Boy to a modern boy of 8 or 9 when he was physically equivalent to an 11 or 12 year old, and assuming unreasonable growth rates (modern human boys do not double in height between 9 and adulthood),

This page used to claim that Tasmanian aborigines were not interfertile with Europeans, which would imply that they belonged to a different species. Scott has since removed this claim, probably in response to people who pointed out that there are thousands of living humans who are descended from both Tasmanians and Europeans. However it speaks very poorly for his competence or reliability that he ever made such a ludicrous claim in the first place. Where on earth did it come from?

Nebraska Man

As my web page points out, most scientists of the time were rightly skeptical of Nebraska Man, and it was debunked before it had any real effect on ideas about human evolution. Scott was familiar with my page (since he copied my illustrations), but he reverses this to say, on no apparent evidence, that Nebraska Man had "wide-spread acceptance".

According to him, "Entire paintings, life-sized models, and museum exhibits were created in honor of this 'discovery'". I know of precisely one illustration of Nebraska Man: the Amedee Forestier drawing in the Illustrated London News, which is shown on his web page. I would like to know which other paintings, models and exhibits he is referring to. I suspect they do not exist.

He refers to paintings of Nebraska Man with "a wife and children", possibly copying from other creationists who have said the same thing. Again, I would like to know which paintings he is referring to, since the illustration on his web page clearly has no children in it.

Conclusion

In short, many of Scott's claims are so bizarre that they do not appear to be derived even from other creationist literature, and they certainly did not come from the mainstream scientific literature. Frankly, it is hard to escape the conclusion that many of his "facts" were plucked out of thin air.

References

Herbert W. (1983): Lucy's uncommon forebear. Science News, 123:92.

Holloway R.L. (1996): The handbook of human symbolic evolution. Eds. Lock A., Peters C.R. Clarendon Press, Oxford.

Howells W.W. (1993): Getting here: the story of human evolution. Whalesback Books.

Leakey R.E. (1994): The origin of humankind. New York: BasicBooks.

McHenry H.M. (1986): The first bipeds: a comparison of the A. afarensis and A. africanus postcranium and implications for the evolution of bipedalism. Journal of Human Evolution, 15:177-91.

Oxnard C. (1975): The place of the australopithecines in human evolution: grounds for doubt? Nature, 258:389-95.

Richmond B.G. and Strait D.S. (2000): Evidence that humans evolved from a knuckle-walking ancestor. Nature, 404:382-5.

Walker A.C. and Leakey R.E. (1993): The Nariokotome Homo erectus skeleton. Cambridge,MA: Harvard University Press. (a volume of papers about the Turkana Boy skeleton WT 15000)

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