You are maintaining a small population of fruit flies in the laboratory by transferring a small number of the flies to a new culture bottle after each generation. after several generations, you notice that the viability of the flies has decreased greatly. what is the best way to reverse this trend?

Cross the flies with the flies from another population

Explanation:

Inbreeding is the mating between the closely related individuals of a population. Inbreeding reduces the viability of the progeny over a generation since it increases homozygosity. When the flies of a small population interbred over generations, the increased homozygosity reduces the viability of the flies. To counteract it, one should mate these flies with the flies from another population. This would increase heterozygosity and thereby would increase the survival and fitness of the progeny.

when it is at an intermediate population density

answer >   yes we do, women; have three holes, urethral opening(pee hole, vagina, and the women pee/girls pee out of the urethra like the men do; only they have a single opening to pee/ejaculate.   (sorry if i'm too forward with this, but this is for a biology class, isn't it? )

hope that !         : )