AP®︎ Biology: Topic 7.9 Flashcards

A branching diagram showing relative relatedness based on shared derived characters, not time scale.

A branch point representing the most recent common ancestor and a speciation event.

The end of a branch representing an observed species or taxonomic group.

The lineage least closely related to the others, used to root the tree.

Shared characters occur in multiple groups; shared derived characters evolved later and indicate common ancestry.

Body parts with similar underlying anatomy due to common ancestry, despite possible different functions.

Comparisons of physical traits in living or fossil organisms used to infer evolutionary relationships.

Molecular data are usually more accurate; morphology can be misleading from convergent evolution.

Independent evolution of similar traits in unrelated lineages due to similar selective pressures.

A method estimating divergence time from the rate of accumulated molecular changes.

Using dated fossils to estimate when lineages diverged on a phylogenetic tree.

On phylogenetic trees, longer branches indicate more evolutionary change; cladograms are not scaled.

An ancestor and all of its descendants considered as one evolutionary group.

Paraphyletic groups exclude some descendants; polyphyletic groups combine members from different ancestors.

Establishing the ancestral base of a phylogeny, usually by comparing the ingroup with an outgroup.

Branches can rotate around a node without changing the evolutionary relationships shown.

Lineages sharing a more recent common ancestor are more closely related than those diverging earlier.

Branching diagrams show relationships, but only phylogenetic trees indicate evolutionary change and often time.

DNA or protein sequence comparisons infer relatedness, with greater similarity indicating closer ancestry.

Testable models of evolutionary relationships that are revised when new evidence appears.