Answer:
The trait being described is the ability to fly in rainy season.
Explanation:
The trait being described is the ability to fly in rainy season. The people with bat wings and people with bird wings are present in the population. The event lead to the change in allele frequency because the population of people with bird wings die due to starvation. Yes, the bat wings were adapted to that environment so they are able to survive. The change make the population less similar to other populations because population of people with bat wings increases as compared to other population. Yes, the new population change for the better of the ecosystem because the population is able to controls the population of other species in the ecosystem.