ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related institutions.
*****************************************************************************

Certainly selection is removing people from the population, but there
are two points: Firstly, is it affecting their reproductive rates?
Many illnesses do not, especially those which affect people later in
life. Evolution should not necessarily increase our lifespans; it's
only really concerned with reproductive success. Secondly, and more
importantly, is whether other people are surviving because of superior
genes, genes which make them immune or resilient to the symptoms, and
if those genes are therefore going to be fostered, spread, (further
modified?), and come to typify the population - or if certain people
are being "selected out" by chance or genes which are subpar to the
wildtype.

As I understand it, there are genetic traits which make some people
more resistant to AIDS, but I'm not sure those genes are going to
spread naturally and thereby adapt our species (similar to the lactose
case). I think it's more likely that we're going to address the
problem by continuing to develop medicines and using other means (e.g.
raising awareness, condoms, circumcision), for controlling the
problem. Of course, there probably is some evolution occurring in
areas with high rates of HIV, but I'm not sure it'd be enough or will
go on long enough to typify adaptive evolution (again, that would
likely require quite many generations or much stricter selection and
control of reproductive rates). (And I also, as may have been
noticeable, distinguish between "pruning" and "adaptive" evolution.
Pruning will likely continue for awhile, but I'm not certain that
adaptive evolution is alive and well. I'm not sure we'll find
adaptions like those for lactose digestion or altitude adjustment
continuing to develop in modern humans, at least in technologically
advanced areas.)

But, as I said before, I'm not saying that evolution (either the
"pruning" or "adaptive" kinds) has ceased, only that it has slowed
tremendously and may cease in the near future. Gene therapy, for
instance, will have a huge effect in this regard. Though I suppose we
may still be said to be evolving at that point - though the evolution
will be very different from typical mammalian evolution. It may be
somewhat like bacteria, sharing plasmids, though we may also be
inventing the plasmids, or we may come to integrate more and more
technology into our own biology. Who knows? But even if we continue to
evolve, our subjection to natural selection will be quite different
and may halt.

-Ari

***********************************************************************
For information about the Association of Science-Technology Centers and the Informal Science Education Network please visit www.astc.org.

Check out the latest case studies and reviews on ExhibitFiles at www.exhibitfiles.org.

The ISEN-ASTC-L email list is powered by LISTSERVR software from L-Soft. To learn more, visit
http://www.lsoft.com/LISTSERV-powered.html.

To remove your e-mail address from the ISEN-ASTC-L list, send the
message  SIGNOFF ISEN-ASTC-L in the BODY of a message to
[log in to unmask]