 In this video, I'd like to talk about mutations and phylogeny. Phylogeny is a reconstruction of the evolutionary process of organisms through time. And so we're going to start by taking a genetic sequence that with the CATG representing the different nucleotides and each group of three code for specific amino acid that gets converted into a protein that can act as an enzyme. So we're going to work forward in time. This particular organism divided, but maybe one of the characters mutated when the DNA was copied. So I marked that one in red. So this what going from a C to a G is a point mutation. So one nucleotide changes and it may or may not change the amino acid that's coded for. And this is a substitution mutation. So we could maybe take both of these and say both organisms divide. And maybe this time this organism doesn't actually have any mutations. But maybe this one has what we would call a deletion where that particular nucleotide gets missed because of an error in the molecular machinery. So to sort of keep track of the mutations I'm going to color the two on either side red ones. So we have four organisms now and each one divides here. And then maybe this time there is an insertion, which means that there's an extra nucleotide. Maybe this one actually gets a whole segment of DNA that gets duplicated, that duplication can end up in different places. I'm just going to put it at the end in this case. So let's make that red. So let's say this one ends up with what we call an insertion, which is extra code. So I will make something up. Okay. So now we have I think at 16 sequences with the original one at the top. So basically I've shown a number of different mutations, including a point mutation with its change in one nucleotide, a deletion of one nucleotide, a duplication, which is basically copying a sequence into another place in the genome. There's an insertion. And then one I didn't show was just a rearrangement. So maybe I will make a rearrangement down here. So the rearrangement will be taking the sequence and putting it into a new place. So we'll just highlight those two locations in red. And we have these different styles of mutation. And in the next video, we'll talk about how we can go from the genetic code with mutations into reconstructing the evolutionary history. Thanks for watching.