AP Biology phylogeny and cladograms

What is phylogeny?

The evolutionary history and relationships among species.

What is a cladogram?

A diagram showing the evolutionary relationships based on shared characteristics.

True or false: A clade includes all descendants of a common ancestor.

True, because a clade is defined by common descent.

Difference between homologous and analogous structures.

Homologous: similar due to common ancestry. Analogous: similar due to convergent evolution.

What does a node represent in a cladogram?

A common ancestor where species diverge.

Fill in the blank: Cladistics relies on ____ traits.

Shared derived traits.

What is an outgroup?

A species or group outside the clade being studied, used for comparison.

True or false: Cladograms depict time of evolution.

False, because they show relationships, not time.

What is a paraphyletic group?

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

Difference between monophyletic and polyphyletic groups.

Monophyletic: includes all descendants. Polyphyletic: excludes some descendants.

Which type of data is most reliable for constructing phylogenies?

Molecular data, such as DNA sequences.

What is convergent evolution?

The independent evolution of similar traits in different lineages.

True or false: Morphological traits are always reliable for phylogeny.

False, because they can be influenced by environmental factors.

What are synapomorphies?

Shared derived traits used to define clades.

Fill in the blank: A ____ tree shows evolutionary relationships with time.

Phylogenetic tree.

What is the principle of parsimony?

The simplest explanation with the least number of changes is preferred.

Difference between cladistics and traditional taxonomy.

Cladistics focuses on ancestry and traits; taxonomy may not reflect evolutionary relationships.

What is a phylogenetic tree?

A branching diagram representing evolutionary relationships over time.

True or false: All species on a cladogram are equally related.

False, because branching indicates differences in evolutionary pathways.

Which of the following is NOT a characteristic of a good phylogenetic hypothesis?

Empirical evidence from a single species.

What role do fossil records play in phylogeny?

They provide historical evidence of species and their traits over time.

What is a shared ancestral trait?

A trait inherited from a distant ancestor, not useful in defining clades.