Phylogeny quiz Flashcards

An ancestral trait is a character that existed in an ancestor and is found in its descendants.

A derived trait is a modified form of an ancestral trait that is not found in the common ancestor.

Homology refers to similarities between organisms due to a shared ancestral trait.

Analogy refers to similarities between organisms that arise due to convergent evolution, not shared ancestry.

Convergent evolution is when unrelated organisms independently evolve similar traits due to similar environmental pressures.

Homoplasy refers to analogous structures that arose independently in different organisms.

An example of homoplasy is the wings of pterosaurs, bats, and birds, which evolved independently.

A clade is a group of organisms that includes a common ancestor and all its descendants.

A monophyletic group includes an ancestral species and all of its descendants.

A paraphyletic group includes an ancestral species and some, but not all, of its descendants.

A polyphyletic group includes various distantly related species but not their common ancestor.

An outgroup is a monophyletic group used as a reference point for the groups being studied.

A synapomorphy is a trait shared by taxa and their most recent common ancestor, but not found in earlier ancestors.

A symplesiomorphy is an ancestral trait shared by two or more descendant taxa.

Horizontal gene transfer is the transmission of DNA from one genome to another, often seen in prokaryotes.

The branch point that represents the most recent common ancestor of all bears is the node where all bear species converge on the phylogenetic tree.

The most parsimonious phylogenetic tree is the one that requires the fewest evolutionary changes or steps to explain the observed genetic data.

The pair of organisms that shares the most recent common ancestor is the one that converges at the closest node on the phylogenetic tree.

The two organisms that are most closely related are those that share the most recent common ancestor, indicated by the closest branch point on the phylogenetic tree.