1. Every time we find a new "oldest thus and such" it is usually proceeded by
a large gap in time until the second occurrence of that "thus and such"
During this gap, there is absolutely no evidence of the "thus and such".
Prior to the finding of the new, oldest "thus and such" everyone thought
that the feature was "evolved" or "invented" much much later. This type of
phenomenon occurs no matter what the "thus and such" is. Weaving, farming,
pottery all man-made activities are governed by this phenomena. Thus prior
to the finding of the most recent, oldest "thus and such" any theory based
upon the now second oldest "thus and such" is wrong if it depended upon the
existence of that object at that time.
As an example lets take the manufacture of iron. Iron requires the
pre-invention of some type of bellows. Iron is found in objects from 2900
B.C. I looked but couldn't find the date of the earliest example of a
bellows. I would bet that since they are made of wood and leather that the
earliest bellows is from much later than 2900 B. C. Are we to conclude that
Iron was not made in 2900 B. C.? I think not. Evidence of iron is evidence
of some type of bellows.
The same type of sporadic preservation occurs in the fossil record. If you
were to find a whale in Permian strata, then you would certainly disprove the
concept that the Mesonychid gave rise to the whale. But for there to be a
seven million year difference between a particular mesonychid and the
earliest whale is not that big a deal. By the way, Mesonychids first
appeared in the Middle Paleocene which is earlier than the Eocene appearance
of the earliest whales. (See Frederick S. Szalay, "Origin and Evolution of
Function of the Mesonychid Condylarth feeding Mechanism" Evolution
23:703-720 Dec. 1969, p. 705) This would put the first Mesonychid at aprox 60
million years ago and the first whale Pakicetus at 52 million years ago.
Thus Mesonychids were on the earth first. But even if they weren't, it
doesn't matter if the gap is not too great.
glenn