Bacteria & Sex

How primitive Is sex? Most biologists have thought that bacteria, which are simple, one-celled organisms, multiply only by division. At Yale last week, Bacteriologist E. L. Tatum emerged from his lab waving proof that even bacteria sometimes act like male & female.

Bacteria act that way only in rare genetic emergencies. Dr. Tatum selected two groups of Escherichia coli (bacteria which Jive in the intestines) and watched them. They multiplied normally by splitting in two, a solitary process. Then Dr. Tatum bombarded some of them with X rays and ultraviolet light. This damaged their insides. The metabolic cripples could still multiply by division (when coddled), but Dr. Tatum hoped that offended nature would somehow force them to repair their deficiencies.

He mixed two strains: one which could not produce vitamins, and another which could not produce certain amino acids. Because of experimental difficulties, Dr. Tatum did not see what happened next; but presently he had a crop of normal Escherichia coli. Their genetic completeness could come only from a combination of both strains. He concluded that the contrasting strains had mated and fused, the good qualities of each repairing the deficiencies of the other.

This file is automatically generated by a robot program, so reader's discretion is required.