 Let's look at the most recent eight organisms that we produced with some of these mutations. And we can see how well we might be able to reconstruct how they're related to each other. We would do that by seeing which of them have the same mutations in them. So if we start at the right end, all of them have the same sequence up to this spot here. And some have a C, some have a G. So we have this difference here. If we keep going down the genome, organism G has a mutation here that none of the others share. Organism C has one here that none of them share. And then they're no longer aligned because it looks like this one has a deletion. And this one may have...let's see how they line up. So we can see the AAC is the same in most of these, except this one. So it looks like maybe that AAC got deleted in organism C. And then we have CCA in a lot of them, followed by GAA. But then this organism has the AA has a genetic difference here that is not present in the others. The others all have the GAA. When we start looking near this TCC, there's a variation here and here, whereas all the others have a G in there. When we look a little farther along, there's quite a bit of genetic variation right in here. So let's try looking at the end of this TCT, which all of them have. So then we have after that TCT, we have a G here, a C here. So this is different. This is different. But the others are all the same. Only one has the AAA and the sequence. Only one has the GG or the T here. Only one has the end and one has this TGA. So I think that all of these differences seem to be unique to individuals. The next step would be to see if we can use these mutations to understand which organisms are related to each other. Half of the organisms have a G here and half have a C. And so I'm going to divide these out into two categories, one and two. There's only one with this mutation, but there are two with these. So they both happen to be in category two. So we'll say maybe those two are related. Two of the organisms have a mutation at the same site, but it's not the same mutation. So I don't know that that tells us anything about the relationships. And then these over here are all unique and variable. So if we were going to do some statistics on them, we would divide the organisms up by their shared mutations. We'd have two overarching groups, ones and the twos, with a subgroup within the twos that I've labeled A here. So for the ones, we have A, C, E, and G. And for the twos, we have B, D, F, and H. And then within the twos, we have D and H closely related to each other. So I'm going to move my D. So what I've done is I divided these up into groups that are more closely related to each other based on their genomes. And we can put this into what we call a phylogenetic tree. And the idea here is that we would be able to use the variations in mutations to reconstruct which organisms are closely related to each other. But we would show this as an idea of evolution through time. So B and F and H and D are more closely related to each other. And so each organism is at the tip of a tree branch. And then we show that B and F had a common ancestor and H and D had a common ancestor. Because I've coded where the mutations actually were, we can see that H and D had a common ancestor with the AA at the site, whereas B and F didn't. And B and F have the same ancestors as the other organisms. But then what we could do is we could say, okay, all of the ones in group two had an ancestor that had a G at this location. Whereas all of these, A, C, and E, we'll say that this is the branch that had the G and this is the branch that had the C. And these all branched off and got these different mutations like the ones over here did as well. So I will label this one as having the AA and this one would have the GA. And it turns out that all of these over here also have the GA. So if we were going to read this tree, there's some ancestor to all of these organisms. And at some point one of its descendants had a G at this location. The other had a C at that location. And with division through time, the organisms, the descendant from the one with G had another mutation that led to a GA being on one side and this other position and an AA on the other side. And then more mutations happened that differentiated the individuals that we have preserved. We can look and see what characteristics the organism, original organism had by looking at all the similarities of the genes. So components of the genes that are all the same are all of these. So the ancestor, because this is shared by all of the genes, we can say it probably had the C, A, T, G, A, C, G, T part of the code. And then if we look at this next section, we have the C and the G. If we look at this next section right in here, we can see that almost all of them have a G, C, G, G, A, C, AA. One of them is different and that's this organism right here. So there are two different interpretations since it's different. One is that there was a mutation along this branch that caused the difference right here. And that would mean that the ancestor had this whole sequence, but it was just changed in one of these organisms. So I'm going to put a star in. So this is either C or G. Half of each organism has each one. And then we can say that it probably was G, C, G, G, A, but there is one difference right here. So the general idea I want you to come away with is the thought that the variations in the genome preserve the evolutionary history. Phylogenies can also be constructed from the morphological characteristics of fossils. And the key is to look at the organisms, see what the similarities are, and try to reconstruct the evolutionary history. So thanks for watching.