00:01
In this question, we're presented with a phylogenetic tree.
00:04
And in the phylogenetic tree, we're basically comparing the evolutionary relationships between various organisms.
00:13
And the way that we read a phylogenetic tree is that if we were to look at it like so, right, we have these various branch points.
00:31
Okay.
00:32
And we'll just leave it like that.
00:34
So what does this mean? so basically, when you have a branch point, that means the intersection of two lines, like right here, is going to be the last common ancestor between two different organisms or two species.
01:00
So up here, we can call these species a and species b or organism a and organism b.
01:07
Their last common ancestor was right at this point.
01:13
So we would say that a and b are relatively closely related.
01:17
A and b are more closely related than a, b, and c would be.
01:24
Right? because the last common ancestor between a, b, and c would be at this branch point right here.
01:35
So using this knowledge, going back to our question, right? we have the human, chimp, gorilla, and orangutang.
01:43
And basically, we could just add, you know, this third line here.
01:48
And we would say that this is the human up here, right? we've got the chimp.
01:55
Obviously, we don't have a in this case.
01:59
Right.
02:01
We'd get rid of this.
02:08
And then we've got gorilla and orangutang.
02:16
So, kind of like we had a and b...