Which of the following describes vicariance? a. Small populations coalesce into one large population. b. A population is fragmented into isolated subpopulations. c. Individuals colonize a novel habitat. d. Individuals disperse and found a new population.

Video transcript

Hi everyone. Let's look at our next question. It says the separation of a group of organisms by a geographical barrier, resulting in the differentiation of the original group into new varieties or species is referred to as our choices. Our catastrophe is um, or catastrophic ism genetic drift, Random selection and by carrion's when we're talking about separation of a group by a geographical barrier and then resulting in the development of different species as a result, the term we want is choice di Vicari ins. But let's look at our other choice is to understand what the difference is and why they're not correct. So choice A is catastrophic ISM. And that is the idea that changes in the earth's crust are a result, physical forces in the past that can't be observed today. And in biology specifically as explanation for disappearance of species, especially in mass extinctions. Oops! So for instance, the idea that, you know, we couldn't explain why did the dinosaurs disappear and we would say, oh, a giant meteor hit the earth and caused all these effects that resulted in that. Um it took us a long time before we could actually observe some physical evidence that might explain that. So it goes into explaining why would you suddenly see a species going extinct? So that but that is not referring to separation by geographical barrier. So that's why that is not the correct term. Then we have genetic drift. And with genetic drift, we're referring to the variation in the relative frequency of Jenna types in a small population due to random chance. So the idea is that if certain individuals with certain Jenna types do not survive, do not reproduce. You can lose those Jenna types in a small population. Just do not due to natural selection, but just due to random chance um that having a greater effect in a very small population. So again, not referring to that separation by a physical barrier, so not our answer. And finally, random selection. Well, that would be as opposed to natural selection. So certain Jenna types decreasing in frequency, oops, due to random chance. So it's not that certain traits were maladaptive or anything else. Just random chance occurring at certain individuals with certain Jenna types failing to reproduce. So again, we're not talking about that here, we're talking about the separation by a physical barrier. So that's why choice C is not a correct answer. So separation by a geographical barrier resulting in differentiation of the original group into new species. On either side of that barrier is choice. The Victorians see you in the next video