Ape fossil record

Lloyd Jacobs (71640.2463@compuserve.com)
18 Aug 1995 15:52:33 GMT

ann.nunn@sstar.com writes:
>NE>>Why not? Why don't we have a fossil record for gorillas or chimps?
>NE>I may have spoken too soon about not having a fossil record for gorillas
>NE>and chimps. There are fragments and reasonably complete fossils that MAY
>NE>be gorilla or chimp precursors. However, no one really agrees about the
>NE>systematic position of these specimens, and so it seems safest not to
>NE>make any extravagant claims about them.
>So there are no books about chimp or gorilla evolution. How about
>journal articles?
>NE>Its not clear why we don't have a better fossil record for the African
>NE>apes. One suggestion is that the ancestors of these apes were probably
>NE>inhabitants of rain forest, which is an environment notably inhospitable
>NE>to preserving bone.
>That is certainly a reasonable possibility. Nevertheless, have not
>SOME fossils been discovered?
>NE>A more likely explanation is that the appropriate fossil bearing
>NE>sediments simply haven't been discovered yet. I expect this situation
>NE>will change.
>Not much money has been allocated to this research on fossil simians,
>has it? And whatever bones have been accidentally discovered have been
>mostly ignored once they were labeled non-humanoid, like that box of
>junk in which Clark recently found the ankle bone and apish foot.

You have to remember how fossils are found, as well. Almost all the african hominid fossiles were found
by somebody walking over vast stretches of eroded sediments.

To find an ape fossil, you not only have to be in a place where they once lived and were fossilized,
but you also have to have erosion to bring the fossils to the surface just at the time your survey is
being done. Forests are generally depositional environments, not erosion zones. If there are no fossils
visible, the odds of finding them are vanishingly small.

Also, they have to be there when you are. If Lucy had eroded out a year or two earlier, she might have been destroyed by
various mechanisms (such as trampling by goats) before a keen-eyed paleoanthropologist spotted her!