I think it's called a hypothesis
Evolution :).
Descent with modification helps to explain anatomical similarities among certain species. The bones of the forelimbs of humans, cats, and bats (you can add in penguins, alligators, and more) are used in different ways but have similar structures.
The best explanation is that these animals have a common ancestor. With new generations, new species emerged by natural selection from different populations, and with this, the bones become better for different tasks.
The forelimbs and other such structures with anatomical similarities due to a common ancestor are called homologous structures.
There’s a lot of stuff here
Answer:
Gills
Explanation:
Sharks are fishes and thus have gills through which they absorb oxygen from the water.
On the other hand, Whales being mammals use lungs to breathe. They can’t directly obtain oxygen from water.
