A combining of separate populations into one large population

A time interval of approximately 1000 years

An event that splits a single lineage into two lineages

A documented piece of fossil evidence

Organisms living now cannot be related to extinct organisms that died out thousands of years ago.

Because they are physically separated, two organisms living in completely different parts of the world cannot be related.

For organisms to be related to one another, they must share similar physical traits.

A relationship exists between any two organisms because they share a common ancestor.

A root represents all living species, whereas a node represents a single species.

A root represents living species that have undergone little or no evolutionary change, whereas a node represents living species that have undergone evolutionary change.

A root represents an extinct species, whereas a node represents a living species.

A root represents the earliest ancestor that all species have in common, whereas a node represents later ancestors that some species have in common.

Rotation of lineages around a node can change the meaning of a phylogenetic tree.

A node is another word for branching point on a phylogenetic tree.

Both large and small groups of organisms can be used to construct a phylogenetic tree.

A phylogenetic tree is a representation of evolutionary relationships among organisms.

population

lineage

clade

taxon

date a fossil

compare developmental stages within a species

classify a newly-discovered species

predict effects of environmental change on an organism's life span

Homologous

Convergent

Phylogenetic

Ancestral

provide information about when specific traits evolved.

help pinpoint when a particular genetic mutation occurred.

allow biologists to make predictions about the relationship between traits and selective pressures.

identify the sequence of evolutionary change in a particular lineage.

Cow; whale

Whale; lizard

Lizard; hawk

Horse; cow

Homologous traits

Homoplastic traits

Derived traits

Synapomorphies

homoplasies

synapomorphies

convergent traits

parsimonies

All similar traits are evidence of relatedness

All shared traits are synapomorphies

All synapomorphies can be classified as either ancestral or derived traits, depending on the point of reference.

Some traits can appear to have different origins but evolved from a common ancestor

through evolutionary reversal.

resulted from synapomorphy.

arose by convergent evolution.

evolved as homologous traits.

share the same ancestral genes.

The bones in birds and bats are similar in appearance, whereas the wing structures in these organisms are very different.

Bone traits are governed by fewer genetic elements than wing traits, which are more complex.

Bone traits are under much different selective pressures from the environment than wing traits.

Bone traits existed in a common ancestor from long ago, while wing traits evolved after the bird and bat lineages split.