Question

The factor most likely to result in a decrease in the size of a specific population is _____.

Answer 1

I believe the answer would be something like... there is a drought which causes a decrease in water availability which would then cause the population to decrease. The same thing also happens with food. Hope this helps. :)

Answer 2

The factor most likely to result in a decrease in the size of a specific population is Famine.

Famine can causes shortage of water and food that can vanish a huge population from the earth.  

A famine can be a result of inflation, extreme weather, conditions and imbalance, war, and crop failure or government policies. A famine at a certain area can cause starvation, deprivation, high mortality rate and disease wide spread.