Use a highlighter to color any amino acid that varies among the species. (Color that amino acid in all sequences.) e. Primates and rodents diverged between 60 and 100 million years ago, and chimpanzees and humans about 6 million years ago. Compare the amino acid differences between the mouse and the C, G, R species with those between the human and the C, G, R species. What can you conclude?

Video transcript

Welcome back. Our next question asks based on the sequence alignment of the different species, which of the following statements about the human origin is true and were given um the single one letter amino acid coat of a short segment. These would be the amino acid codes for a protein found in all of these species lined up to compare them and all of our choices involve which of these species is most closely related to humans. Um Again, if I were on a test, I want to look at these over and I just know from common sense that chimpanzees are going to be more closely related to humans than mice, frogs or fish. My other choices, but let's go through and confirm that by looking at our sequences and comparing them. So the human sequences on top, And I'm just going to look down the line and highlight any time an amino acid differs from the human. So let's start right here in the first column. Let me see the human has G. And we'll just highlight mouse. Frog and fish have differences. Next column, they're all the same. Next column, frog and fish are different. Next all the same. So I'm just going to go through down each column and any time there is a amino acid that differs from the human sequence. Just highlight it here. Then I'll be able to quickly glance over the whole chart and see which has the least difference. So that was very quick. I look back over my chart and I see that the mouse has just a single amino acid difference from the human. The chimpanzee, though, is identical, and then, as I might expect, frog and fish have more differences, so that makes it easy to pick choice. A humans are closely related to chimpanzees. Got a nice easy one that's confirmed by kind of common sense knowledge here. Obviously we wouldn't expect mice, frogs or fish to be nearly as closely related to humans. I'll see you in the next video.