No. 112: Jul-Aug 1997
When we scarf down a hamburger, we ingest bovine DNA. The textbooks say that this alien DNA is destroyed during digestion. Otherwise, it might "somehow" be incorporated into our own DNA, leading in time to our acquisition of some bovine characteristics! You'll recall that cannibals thought to acquire the virtues of their slain enemies by grabbing a bite or two! But this all sounds pretty farfetched, doesn't it?
Maybe not. When W. Doerfler and R. Schubbert, at the University of Cologne, fed the bacterial virus M13 to a mouse, snippets of the M13's genes turned up in cells taken from the mouse's intestines, spleen, liver, and white blood cells. Most of the alien DNA was eventually rejected, but some was probably retained. In any event, alien DNA in food seems to make its way to and survive for a time in the cells of the eater.
(Cohen, Philip; "Can DNA in Food Find Its Way into Cells?" New Scientist, p. 14, January 4, 1997.)
Comment. We are only half-kidding when we ask if food consumption could affect the evolution of a species. After all, our cells already harbor mitochondria, which are generally admitted to have originally been free bacteria that were "consumed" by animal cells. The process even has a name: "endosymbiosis." See: SF#47/189.