Some biologists summarize evolution by natural selection with the...

Question

Some biologists summarize evolution by natural selection with the phrase 'mutation proposes, selection disposes.' Mutation is a process that creates heritable variation. Explain what the phrase means.

Accepted Answer

Welcome back. Let's move on to our next question. It says how does genetic variation among individuals of the same species? Help them avoid species extinction? Let's remember that species extinction equals complete die out. So we want to think about what does genetic variation do for a species that prevents all the members of that species from dying out. So with that in mind let's work through our answer choices. Choice A says it helps all of them survive amidst changing environments. Well this will not be correct. Um The genetic variation means that they have different traits that might allow some to survive. They are adapted to a certain environment. The environment changes. Perhaps one of the mutations gives them some sort of advantage in the new environment and they survive even while perhaps um individuals adapted to the old environment die off. But genetic variation doesn't help all of the animals survive. Natural selection will still cause some of them to die out. If the environment changes Choice B says it enables individuals with suitable traits for various environmental conditions to survive and reproduce. This is going to be correct. I won't select it just yet because sometimes questions like this are a little bit nebulous and we might want to make sure there's no better description or better answer. But again it says that if in the environment changes genetic variation means you have different genotype, different phenotype, different traits even among the same species. And it means even if for instance um things change and a number of the individuals die off, you might have certain traits that are advantageous in the new circumstances and those individuals with those suitable traits are able to survive and reproduce, preventing species extinction. So that's a specific way that genetic variation helps avoid extinction. Troisi says it facilitates ancestral traits being passed down from generation to generation. Well, this would not be the correct answer because genetic variation would cause changes in traits. So ancestral traits would be traits that are passed down and conserved for a long period of time despite evolution. But genetic variation causes changes in genotype changes and traits. And so this is not going to be a correct description of genetic variation. Choice. D says it aids them all in becoming resistant to natural selection. Well, no, this is not correct again, the issue is you're still going to have natural Jenna acting and genetic variation allows species to survive through natural selection because changing environments might favor new different traits. So it looks like our choice B is our correct answer. So how does genetic variation among individuals of the same species help them avoid species extinction? Choice be it enables individuals with suitable traits for various environmental conditions to survive and reproduce. See you in the next video

Some biologists summarize evolution by natural selection with the phrase 'mutation proposes, selection disposes.' Mutation is a process that creates heritable variation. Explain what the phrase means.

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