Traits that are derived from a common ancestor, like the bones of human arms and bird wings, are said to be               .

Video transcript

Hi, everyone. Here's our next problem. The four limbs of frogs, birds, rabbits and lizards look very different, but they share a common ancestor and are made up of common bones. These traits are blank. Uh When we have structures that are different and form and, or function, but descent from a structure and a shared ancestor, that is a homologous trait. And when we look at our answer, choices, we see that choice B is homologous. So let's just look through our other answer choices to understand why they're not correct. Choice A is analogous. Well, that's the opposite of what we have here. An analogous traits. You have similar structures not do to common ancestry and it can be tricky to keep these two things straight, uh which is homologous, which is analogous. One way to remind yourself might be that when you think of an analogy like on sat an analogy is when you're taking two different things and trying to make a comparison between them. So maybe imagine I'm starting with two different species and they develop a similar structure. So that might be one thing that, that can help. So as we said, choice B homologous is the correct answer. Choice. C synonymous, well, synonymous mutation is when you have a change to a DNA sequence in a codon that doesn't change the amino acid being coated for. Um So as you might recall, uh amino acid, each amino acid can have multiple codons that code for it. So if you change a base pair in the codon, but you happen to change it to a codon that codes for the same amino acid, you can have a mutation to the DNA that doesn't change the amino acid, it codes for. And therefore you might not see any uh Benoy change since you might not see any change to the protein. So that's not our answer. Oh, let's cross out a here as well. And finally, choice d innate. Well, an innate trait is uh an inborn behavior that is inherited rather than learned. So this wouldn't refer to a structure at all, but a behavior. So not our answer choice. So again, uh traits that look different, but due to sharing a common ancestor made up of common bones, our choice. B homologous. See you in the next video.