00:01
For this question, we are talking about phylogenetic trees.
00:05
So a phylogenetic tree, or known as a phylogeny, is just a diagram that depicts certain inferred evolutionary relationships among biological species.
00:16
So here we just have a sample of a phylogenetic tree.
00:19
We have lamprey, sunfish, noots, lizards, bears, and chimpanzees.
00:24
And each little dot here is going to represent the common ancestor.
00:29
So lampreys and all of these other species used to have a common vertebrate ancestor.
00:35
However, then jaws happened.
00:39
So we started having jaws.
00:42
And then the lampreys did not have jaws.
00:44
So that is an evolutionary event that occurred.
00:46
And then it continues all the way down to the common mammal ancestor between bears and chimpanzees.
00:53
So this is just an example.
00:55
But what can phylogenetic trees help scientists do? well, can they help to trace the evolutionary events in a lineage of organisms? absolutely.
01:07
So, for example, here we can see that there was an event where we used to have a common ancestor where there was vertebrates, but then there was an event where we had jaws evolve, and that is, for example, one evolutionary event, and that is in this lineage of organisms...