Point 3:
Because of the rarity of
fossil hominids, even many of those who specialize in the evolution of
man have never actually seen an original hominid fossil, and far fewer
have ever had the opportunity to handle or study one. Most scientific
papers on human evolution are based on casts of original specimens (or
even on published photos, measurements, and descriptions of them).
So? Menton
seems to think that there is a problem with performing analyses based on
measurements that other people have taken. That is nonsense. A
few years back, I was at a conference where a paper was given in which
the author was attempting to show the differences between subtle details
on various fossil crania. The striking criticism of the study was
that it was based on casts, not on original fossils and, because of
this, the analysis was questionable. When I did my dissertation on the
origins of modern human crania, I had measurements of almost all of the
original crania that had been taken either by my advisor or by other
researchers in the field, who had then published them. Almost every
paper done on human evolution is based on measurements from the original
fossils. The only examples where this is not happening is where the
original skulls are missing, as with the
Homo erectus remains
from Zhoukoudian, which vanished during the run-up to the second world
war, or the European Mladec remains, which were destroyed when the
allies bombed the castle in which they were housed. Even in those
cases, copious measurements were taken of the originals and, in the case
of the Zhoukoudian remains, comprehensive photos were taken. There is absolutely nothing wrong
with doing analyses based on measurements from the original fossils,
especially where the photos are clear and detailed. Bill Howells took
detailed measurements of the Near Eastern Qafzeh 6 cranium and then
kindly sent me the measurements for it.
All of science is built on what came before and the observations of the those scientists are absolutely invaluable.
Point 4:
Since
there is much more prestige in finding an ancestor of man than an
ancestor of living apes (or worse yet, merely an extinct ape), there is
immense pressure on paleoanthropologists to declare almost any ape
fossil to be a “hominid.” As a result, the living apes have pretty much
been left to find their own ancestors.
More
nonsense. There are palaeoprimatologists that spend their entire lives
researching the prehistory of non-human primates. A check of Google
Scholar revealed over forty-nine thousand papers dealing with non-human
fossil primates. One of the most productive and exciting aspects of
fossil primate studies is the search for the last common ancestor
(LCA). This involves an in-depth study of Miocene apes. Another area
of important study is the origin of the large-bodied primates and the
split between the Old World and New World monkeys. When Menton states
that the living apes have been left to find their own ancestors, he
forgets the media circus that
surrounded the find of the fossil primate Ida, which shed light on the origin of primates as a group.
Point 5:
In
contrast to man, apes tend to have incisor and canine teeth that are
relatively larger than their molars. Ape teeth usually have thin enamel
(the hardest surface layer of the tooth), while humans generally have
thicker enamel. Finally, the jaws tend to be more U-shaped in apes and
more parabolic in man.
The
problem in declaring a fossil ape to be a human ancestor (i.e., a
hominid) on the basis of certain humanlike features of the teeth is that
some living apes have these same features and they are not considered
to be ancestors of man. Some species of modern baboons, for example,
have relatively small canines and incisors and relatively large molars.
While most apes do have thin enamel, some apes, such as the orangutans,
have relatively thick enamel. Clearly, teeth tell us more about an
animal’s diet and feeding habits than its supposed evolution.
Nonetheless, thick enamel is one of the most commonly cited criteria for
declaring an ape fossil to be a hominid.
Menton may be correct in his statements about enamel thickness. Enamel thickness
may be a better indicator of dietary adaptations than of morphology, but, where primates are concerned, that is only true of enamel thickness. It is not true of tooth morphology. Primatologists
have no trouble telling baboons from humans. They do not have the same
features. Fossil and modern baboons are quite different from humans,
even human ancestors.
In 1924, when the
well-trained anatomist Raymond
Dart was given the deposits that had the Taung child in them, he knew
immediately that the teeth did not belong to any fossil baboon. It wasn't the thickness of the enamel that tipped him off. The dimensions were similar to those of an infant human and the morphology of the canine and the premolars was like that of humans.
Remember, at this time, there were very few other prehuman ancestors
with which to compare it, and no australopithecines.
Teeth are, actually, one of the most conservative features on a skeleton
and change very little over time. For example, the Y-5 molar pattern
that we have in our mouths is first found in
Aegyptopithecus,
from the Oligocene epoch, some 30 million years ago. Furthermore, one of the ways we can tell the new world primates from the Old World primates is the number of teeth they have. New World monkeys have two incisors, one canine, three premolars and three molars in each quarter of the mouth. All Old World monkeys and apes are lacking the extra premolar (bicuspid, if you are a dentist).
We have this same pattern.
These differences are either glossed over or not mentioned by Menton, who simply declares, based on enamel thickness, that the teeth are similar and completely disregards information that doesn't fit his narrative.
Part III here.
