It is true that it is possible for a population to not evolve for a while.
There is something called the Hardy-Weinberg theorem, which characterizes the distributions of genotype frequencies in populations that are not evolving.
There are 5 Hardy-Weinberg assumptions:
- no mutation
- random mating
- no gene flow
- infinite population size
- and no selection (natural nor forced).
You can see that some of these are kinda extreme and really hard to get, but with approximations, we can work.
For example, instead of an "infinite population size" we have enough with a really large population, such that genetic drift is negligible.
Concluding, yes, it is possible (but really difficult) for a population to not evolve for a while (at least, in nature), as long as the 5 assumptions above are met.
If you want to learn more, you can read:
brainly.com/question/19431143
<u>Answer:</u>
Cyanobacteria start producing pure oxygen around 200 million years ago.
<u>Explanation:</u>
Many scientists believed that Earth did not have any oxygen. Cyanobacteria or the blue green algae are the microbes which produced oxygen for the first time with the help of photosynthesis. This was around 4.5 billion years ago: after Hadean eon.
They were very simple, but they produced oxygen in the early earth’s atmosphere. So, they brought evolution on earth. This “blue-green algae” exists in salt water, rocks and soils and play a major role in maintaining the ecosystem.
Explanation:
In all living system we can always find basic elements carbon, oxygen, nitrogen and hydrogen, carbon is the basic building unit contained in living matter. The percentage of carbon in the mass of living matter is 19.0% oxygen and hydrogen are present in almost all organic compound which creates living organisms.
