Yes well you could be correct. There may have been many cetacean species
that existed from 45 to 35 million years ago, with gradually increasing
EQ's, that were not in existence long enough for them to be seen in the
fossil record.
But, that is not the claim made by the authors of this article. They assert
that there was a relatively sudden change in EQ. It is not clear how fast
they think it ocurred or if or how many transitional species may have been
present in that transition. They have no evidence for any EQ between 0.5
and 2.0 at that time.
The part I find interesting is that they dont speculate about a catastrophic
climate change, or some other environmental change in selection pressure as
the cause for the rapid change. They propose that it is the appearance of a
novel ability that is associated with this rapid morphologic evolutionary
change. Since it seems unlikely that a single mutation could result in this
complex change in brain anatomy, or behavior, how does a series of
mutations ocurr over a geologically short period of time, that eventually
lead to a complex novel adaptation?
Received on Sat Nov 6 00:30:58 2004
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