00:02
Hi there.
00:03
Phylogenetic trees are constructed to show possible relationships between organisms.
00:11
And by relationships, the phylogenetic trees are set up to look at common ancestors of organisms.
00:25
And this information is determined mostly today based upon dna at the molecular basis.
00:36
So they used to look at what organisms look at.
00:40
Like structural features, but now that we have the tools of dna and molecular biology, that's what's used to construct phylogenetic trees.
00:49
So a phylogenetic tree, there's just going to be one trunk because all living things can be traced back to a single common living ancestor, but then different organisms branch off the tree in different locations, and then those branches, of course, branch off.
01:08
And what we notice is that where they branch off, they had a common ancestor.
01:17
And then that common ancestor may branch off into more current species and so forth and so on.
01:24
So that's a phylogenetic tree...