Dr. Silver agrees that genes confer an advantage - nothing more.

When these genes confer a calm disposition or a perfectly turned tail, such prodigious dissemination is desirable.

Antibiotic-resistance plasmids frequently contain genes conferring resistance to several different antibiotics.

These genes do not confer antibiotic resistance.

C1 Bad genes may once have conferred survival advantages.

It remains to be determined if these inserted genes confer a selective advantage.

Dr. Emlen emphasized that "genes confer only a predisposition, not a destiny."

Replies: Genetic engineering directly modifies genes of a plant or animal to confer some desired trait, such as disease resistance.

It is likely that multiple genes confer vulnerability to trichotillomania.

The other genes, the researchers speculate, may confer resistance to former scourges like pellagra, tuberculosis and leprosy.