Question

A population of short-finned fish and a population of long-finned fish live in a lake. Fish with long fins swim faster than fish with short fins, which means they escape predators more often. According to natural selection, which of the following will happen over time?

Answer 1

A) long-finned fish will increase

Answer 2

The trait small fins will disappear. This is, eventually, there will be no more fish with small fins

Step-by-step explanation:

Because long fins are being positively selected in nature (positive natural selection), the small fins will eventually (over time) disappear. That is, there will be no more fish with this characteristic, there will be no more fish with short fins.

The above is unavoidable unless there is a good trait (another) linked to the small fins. If there is a good characteristic linked to small fins, that good trait will keep the short fins in the population.