The answer would be fats and proteins.
Whales are related back to a hairy, 4-legged land mammal that eventually led to the formation of flippers without phalanges, a blow hole that became more dorsal, and other defining features. All of this has been backed by fossil evidence, especially that found within a certain desert region (can’t remember the name) that has a vast amount of whale fossils from many different time periods
A hypothesis is an educated guess. This is part of the scientific method developed in science to explain natural phenomena in the environment. Usually scientists use the hypothesis in their controlled experiments.
Whether it is a fact or not scientists use the hypothesis as a basis or a starting point for further explanations. This is known as the scientific hypothesis. When an educated guess yields the same results over time, the answer is called a theory. Something that is widely accepted but still needs to be proven and investigated further.
