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

Respuesta :

cross your flies with flies from another lab 
change the temperature at which you rear the flies
transfer only the largest flies
reduce the number of flies that you transfer at each generation
shock the flies with a brief treatment of heat or cold to make them more hardy