Phylogeny and Classification

These flashcards cover key concepts regarding phylogeny and classification from the lecture notes.

What does phylogeny describe?

The evolutionary history of relationships among organisms.

What is the purpose of phylogenetic trees?

To show evolutionary relationships among different groups of organisms.

What is used to construct a phylogenetic tree?

Shared derived characters.

What types of data are used to construct phylogenies?

Morphology, the fossil record, development, and molecular data such as amino acids, DNA, or RNA sequences.

What is a node in a phylogenetic tree?

The point where a branch splits, representing a common ancestor.

What are sister groups?

Two groups that are each other’s closest relatives on a phylogenetic tree.

What type of groups reflect evolutionary relationships according to phylogenetic trees?

Monophyletic groups, also called clades or lineages.

What do shared traits (synapomorphies) signify?

They are derived traits shared between groups of organisms that help define sister taxa.

What is the Principle of Parsimony in phylogenetics?

Trees with the fewest number of evolutionary changes are preferred as they provide the simplest explanation of the data.

What is the significance of the amniotic egg?

It is a shared characteristic of reptiles and mammals that evolved once in their common ancestor.