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Desert Diary


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A question that often comes up in biology classes is something along the line of, "Aren't we harming the human species by our medical sciences allowing people to live that otherwise would be eradicated by natural selection?" The questioners seem to think that our species is degenerating. The reasoning is that individuals that, in an earlier age, would have not survived to reproduce, now do fine, preserving weaknesses. After all, diabetics have insulin shots; poor-visioned people, glasses; and candidates for heart attacks, surgery.

The questioners forget what natural selection is: namely, the interplay between genetic makeup and the environment. We live today in an environment of medical services. This is the condition in which natural selection is now working, not that of a few hundred years ago when diabetes was a death sentence. If we manage to war ourselves back into being hunter-gatherers roaming the desert, then keen sight and low blood sugar once more will be critical. Until that time, however, natural selection will concentrate on the careless driver, the drug addict, and the spirit of war.
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Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.

Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.