Phylogenetic Analysis

Clade

Shows all organisms of a group that share a common ancestor

Common Ancestor

Changes between species generations as time goes on and will continue changing

Tree of life diagram

Divides species by common ancestors (ex. Chordates and Cnideria have a very far back common ancestor)

How common ancestors are determined modernity

Can be determined by biological pathways and the fact that we use DNA similarly.

Eukaryotic life

More advanced life - have a nucleus (can be single celled)

Topology

Specific order/pattern of branching

What branch length represents

Represents the amount of inferred evolution (if there isn’t a lot of evolution over a long period of time then the branch is short) evolution

Why we do Phylogenetic analysis

Can learn about whether traits are shared by species because of a common ancestor or if they’re independently derive, see patterns o history, can see population mixing/splitting events, see speciation events,

how we do phylogenetic analysis

Read branches from root to tip, where branches split it the point of speciation event, collect data about whether organisms are similar or different, can reconstruct historical events on the tree of life, want to minimize amount of converging evolution that is being inferred

What do we learn from phylogenetic analysis

Where mass extinction events occurred (lots of evolution rapidly), where climate change occurred, can see which species are related and solve problems of why specific features are being selected

Monophyletic

One common ancestor and all its descendants - can interpret how diverse it is and how they adapt to things

Polyphyletic

A group of species that includes groups from more than one ancestral lineage

Paraphyletic

Most but not all descendants of a common ancestor