Cladistics Lab

Cladistics lab for bio 2.2

Taxonomy

Classification and naming of organisms

What is the linnean Taxonomy

A hierarchal system to classify and name living organisms

What are the linnean classifications?

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

What is the scientific name?

Genus and species

How many animal Phyla are there?

about 36

Most animals are in…(how many phyla?)

9 phyla

How did Linneaus classify organisms?

He used physical similarities

What is Cladistics?

Using evolutionary relationships to define taxonomic groups

What is a clade

A clade is an ancestor and all of its descendants

Monophyletic

a common ancestor and ALL of its descendants

Polyphyletic

The descendants ONLY, no common ancestor

Paraphyletic

a common ancestor but NOT all of its descendants

What is the difference between Homology and Homoplasy?

Homology are traits passed down from a common ancestor whereas homoplasy refers to traits acquired from being in the same environment.

Taxa/ Taxon

refers to a group of any rank on a cladogram

What are branch tips?

refers to the ranks at the end of the phylogenetic tree

What are nodes?

They are the point in where a lineage splits and becomes a new species.

Out group

a reference for the group we are looking at

Sister group

in relation to the group we are looking at

Apomorphy

A characteristic or trait that is unique to a clade, found in all members of the clade.

Pleisiomorphy

ancestral trait or characteristic may or may not be present in all members of the clade

Which cladogram is incorrect?

Cladogram 4

Maximum Parsimony

evolutionary changes are rare therefore the best cladogram is the one with the fewest evolutionary changes

Maximum Likelihood

Cladograms are based on DNA evidence