Although most salamanders have four legs, the aquatic salamander shown below resembles an eel. It lacks hind limbs and has very tiny forelimbs. Propose a hypothesis to explain how limbless salamanders evolved according to Darwin's theory of natural selection.

Answer 1

From wiki:
Natural selection is the process by which certain heritable traits—those that make it more likely for an organism to survive and successfully reproduce —become more common in a population over successive generations. It is a key mechanism of evolution.

So, what are the reasons for having lack of hind limbs and has very tiny forelimbs?

Survival, most likely.

So, state a hypothesis which states the limbless salamander evolved because of (definition of natural selection).