In this question, there are no options given to choose from. So i would answer this question based on my knowledge. The most likely cause of the observed variation is adaptation and evolution. The birds of that island adapted to the food source and then they evolved as per the requirement of the place and food source.
they're called heterotrophs.
I think it would be that anatomically gorillas are more like humans.<span />
Answer: Robert Hooke
Explanation:
In 1665, Robert Hooke, an English scientist, was the first person to see cells under the microscope and give them a name. This happened when he discovered honey-comb structures which he called "rooms" in the cork of an oak tree while using a magnified object - microscope.