The correct answer is D. The theory of natural selection provided a better explanation of the processes that were being observed by the scientists.They observed that the related species birds found on one island were slightly different from that of the other, and certain portions earth, have the species, which were not found anywhere else.
It overwhelming supported by greater scientific community, and if no experiments have proven it wrong
They are among the first
colonizers of an environment. This way they break down rocks and make nutrients available for other plants. They help in retention
of water in a habitat and also shelter many microorganisms.
They also decompose organic matter hence play an
important role in the cycling of nutrient in the environment.