>> When I was wondering how much of the fossil evidence for human
>> evolution was eliminated by the Y chromosome data, I was asking how
>> many of the fossils used to depict human evolution must now be
>> considered to be "aunts and uncles" as opposed to ancestors. You
>> cannot form a chain of creatures from primate to man consisting of
>> creatures known to have no direct ancestral relationship with modern
>> humans.
Not necessarily. Suppose species A (H. habilis) gives rise to B
(H. erectus), which gives rise to C (us). Species B is very widely
dispersed, but the B->C transition occurred in a part of its range
(Africa). Specimens of B in Asia are still anatomically intermediate
between A and C (because they're virtually identical to specimens of B
in Africa that were our ancestors) even though they're not *direct*
ancestors.
It's even quite possible that none of the African erectus fossils we
have is an ancestor of any modern human, because in any population the
genes of any single individual stand a good chance of going extinct.
But they are still representative of their population, some of whom
probably were our ancestors. These fossils would be closer uncles than
the Asian erectus fossils.
Thought experiment: accept, for the sake of argument, that evolution is
true, and we did evolve from habilis. Take my father, and his father,
and so, until we've got 100,000 generations going back 2 million years.
This would form a pretty impressive transitional series. Now, replace
each of those skeletons with that of one of his brothers. We now have a
series that looks just as gradual, with just as many transitional forms,
even if not one of those skeletons had any descendents.
-- Jim Foley Symbios Logic, Fort Collins, COJim.Foley@symbios.com (303) 223-5100 x9765