Using the following amino acid sequences obtained from d...

Question

Using the following amino acid sequences obtained from different species of apes, construct a phylogenetic tree of the apes. <>

Accepted Answer

Hi, everybody. Let's look at our next problem. It says A common ancestor of two or more species on a Philo genetic tree is represented by. And we have our answer. Choices are different terms describing structures on a hill, a genetic tree, choice, a, a node on a philo genetic tree. Choice be a base choice. C A tip choice D A twig, all those on a philo genetic tree. So let's kind of put up a sample for a genetic tree. I'm gonna put that image up here, shrink it a little. So as we can see, we start on the left side with just a single line and that's the base or root of the tree. And it represents the common ancestor of all the organisms on the tree. So everything on the tree is a descendant of the species at the base or root. But we're looking for just a common ancestor of two or more species on the tree. So not the original common ancestor but something a little further down. That's a common ancestor as you go down. So we're going to eliminate the base, which is choice B. So eliminate choice B, well, as we go to the right, we have our single line and then it branches off going one branch, going up or goes up to one branch, going down to another branch. And some of those continue on the bottom branch here, continues straight to organism X, organism X just as descended almost directly from this common ancestor on the top R branch, then branches off several more times into different species. Well, this point where the single common ancestor divides into two different descendant ancestors is called a node. So I've labeled two nodes already a little further on on the top. But this very first one is also a node. So anywhere that the common ancestor splits into multiple descendants is a note on the pillow genetic tree. And because we're splitting and then from there, it's branching off into two or more species. So on the bottom, we see there's one species on the top, another species that then begins has another node splits into two more descendants. Each of those have nodes where they split into more descendants. The note is what we're looking for. That's would describe that point is the common ancestor of two or more species. So we're gonna pick choice a there and just to be thorough to look at choice, see a tip on a philo genetic tree. Well, the tip is our organism at the very end. So that's just a single organism that's represented. And we look at the phyllo genetic tree to trace back its ancestry to a single root or common ancestor. So the tip is the end, it represents an organism that we're not looking at any of its descendants, an organism alive today. So that is not our answer since we're looking for a common ancestor. And then choice C says, oops, I'm sorry, that was choice. C A tip made that choice D says a twig on a pillow genetic tree. Well, a twig would probably be a branch that doesn't branch any further. There's no more nodes coming from that branch. So the branch I've drawn in the bottom of this tree, just a single branch coming from the original root, common ancestor and going straight to organism X at the tip. So that's a twig branches no further. It has no other descendants. It's not a common ancestor of any more than, it's not a common ancestor of two or more species. So choice D is not correct. So again, a common ancestor of two more species on a philo genetic tree is represented by choice. A, a node on a philo genetic tree. See you in the next video.

Using the following amino acid sequences obtained from different species of apes, construct a phylogenetic tree of the apes. <>

Key Concepts

Amino Acid Sequences

Phylogenetic Trees

Molecular Phylogenetics

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