Chapter 3: Trait Evolution

These flashcards cover key terms and concepts related to evolution and biological diversity as discussed in the lecture notes.

Trait Evolution

The phenomenon that happens along population lineages where changes accumulate and are retained by descendants.

Monophyletic Classification

Classifications that recognize only clades as worthy of names in formal biological taxonomy.

Nested Hierarchy

A structure in taxonomy where classifications are arranged in a nested pattern based on traits that evolved along a tree.

Parsimonious Trait Evolution

The determination of the most parsimonious history of character state changes for a binary trait on a given tree.

Homology

A condition where traits in different taxa are considered homologous if they trace back to a common ancestor.

Common Ancestry

The hypothesis proposing that living taxa share a common origin, leading to the distribution of traits in a nested pattern.

Convergent Evolution

The phenomenon where the same trait evolves independently in different lineages, resulting in non-homologous traits.

Principle of Parsimony

The idea that the hypothesis which makes the fewest assumptions, or requires the least number of changes is preferred when explaining evolutionary history.

Reversal

A phenomenon where an ancestral trait is lost and then re-evolved along a lineage.

Separate Ancestry

The hypothesis that each living taxon has an independent origin and does not share a common ancestor.