Re: Are We Still Evolving?
Alex Duncan (aduncan@mail.utexas.edu)
1 Nov 1995 16:34:09 GMT
In article <46qnil$l7p@cpip.kent.edu> Philip Reno, preno@Phoenix.kent.edu
writes:
>: >Are we still evolving?
>
>: Yes.
>
>Yes, but I'll submit to you that in currently 99.9% of human evolution
>is cultural while only small amounts of changes that effect human
>survivorship si due to natural selection and its effects on the human
>genome.
OK, first I want to know how a post I sent to another group (and then
cancelled) got here.
Let's look at something like presence or absence of 3rd molars. I submit
that in our current state, where we can eat most of our food through a
straw, the presence of 3rd molars is deletrious, and is selected against.
I know what you'll say -- "but most of us have our M3s removed by the
dentist." Removal of M3s is a pretty invasive procedure, that usually
involves anesthesia, and a lot of bleeding. I suspect (I don't know, and
would like to find out) that occasionally people die on the table during
the removal of M3. More likely, people might die from postoperative
infection. These events are probably extremely rare, but they probably
happen. In less developed countries, people probably don't have their
M3s removed, and so are more likely to have impacted M3s, and subsequent
infection and probable death. The point is that however small, there is
probably a selective gradient favoring those who simply don't have M3s in
the first place. In a few thousand years, the human dental formula may
be 2-1-2-2.
And I would agree that most evolution is cultural.
Alex Duncan (I only have 25 teeth and am therefore higher up the
evolutionary ladder than all you poor saps with 32 teeth, though the fact
that I am bilaterally asymmetical does bother me a bit.)
Dept. of Anthropology
University of Texas at Austin
Austin, TX 78712-1086
512-471-4206
aduncan@mail.utexas.edu
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