Question

A group of scientists wants to test the effects of decreased oxygen levels in the water on a population of albacore. What result from this experiment would show natural selection in progress?

Increased reproductive success of individuals who have the ability to survive a variation in oxygen levels
Migration of the albacore population to environments with more dissolved oxygen
Increased reproduction by the albacore population in order to match the increased death rate
Development in the next generation of new gills that are more efficient at extracting oxygen

Answer 1

I think its c im doing the exam rn

Answer 2

The decreased oxygen levels in the water will affect the respiration of the fishes. In order to cope up with the change, the fishes may migrate to a better place with higher levels of dissolved oxygen. This however does not relate to the process of natural selection as the fishes are still the same, genetically and phenotypically. Natural selection acts on those fishes that are able to survive the decreased oxygen levels. These fishes will breed and increase their numbers. The new generation of fishes will be tolerant to the lower oxygen levels. This new phenotype indicates a change in the genetic composition of the fishes.