Question

. Which statement best explains how early life forms that were harmed by oxygen evolved into today's life forms that require it?

Answer 1

You think that harmed ones evolved?

Explanation:

Let's assume that a population of anaerobic individuals live in a area that lacks much oxygen. With the passage of time, oxygen level increases. And individuals that are mutant and have ability to make oxidative respiration become advantegous position. While oxygen level increasing individuals that are aerobic increases in size in the population.

I mean that harmed ones do not evolve, generally, new ones competible to environment become dominant in population by the change in the environmental conditions.

But somewhere else low oxygen level is maintained or newly appeared, anaerobic one continue to live, without dominant appearance of oxygenic ones in the population.

To understand it better, more carefully study about natural selection. Try to gain main point of natural selection.

For any question do not hessitate to ask. :)