Phylogeny and Evolutionary Relationships

These flashcards cover key vocabulary terms and concepts related to phylogeny and evolutionary relationships as discussed in the lecture.

Phylogenetic tree

A diagram that represents evolutionary relationships among species, showing how they diverged from common ancestors.

Speciation

The process by which new species arise from a common ancestor through the divergence of populations.

Basal taxon

A lineage that diverges from all members of its group early in the group's history.

Sister taxa

Groups of organisms that share an immediate common ancestor not shared by any other group.

Monophyletic group

A group that contains an ancestor and all its descendants; also known as a clade.

Paraphyletic group

A group that includes an ancestor and some, but not all, of its descendants.

Polyphyletic group

A group that does not include the most recent common ancestor of its members.

Homologous traits

Traits that are similar due to inheritance from a common ancestor.

Analogous traits

Traits that are similar due to convergent evolution, not inheritance.

Synapomorphies

Shared derived characteristics that are present in a group of taxa but absent in other groups.

Divergence

The process by which two or more related species become more dissimilar over time.

Evolutionary relationships

Connections between species that show how closely or distantly they are related through common ancestry.

Branch point / Node

The point on a phylogenetic tree where a lineage splits into two or more descendant lineages.

Taxa

Groups of one or more populations of organisms that are treated as a unit in biological classification.

Common ancestor

An ancestral species from which two or more species have evolved.

Phylogeny

The study of the evolutionary history and relationships among individuals or groups of organisms.

Lineage

Direct descent from an ancestor; all the descendants of a particular ancestor.