Physical features shared between species because of a common ancestor, like particular skeletal structures
Vestigial structures
Reduced or non functional versions of features that serve little to no function to an organism
Analogous features
Physical features that evolved separately in different organisms in response to the same environmental pressures, like how most species have eyes
Convergent evolution
When two separate species evolve to have common traits independantly
Homologous genes
Related genes found in different species used to determine if and when those species were evolutionarily related to each other
Fossils
Preserved remains of previously living organisms or their traces, dating from the distant past
Strata
Layers of rock that build up which provide a sort of timeline for roughly dating fossils
Phylogenetic tree
Diagram that represents evolutionary relationships among organisms (hypotheses not definite facts)
Taxa
blanket term for groups used for categorizing organisms like domain, family, species, subspecies, group
Branch
Line on a phylogenic tree
Branch point (internal node)
Where two branches diverge on a phylogenic tree
Divergence event
When one population species gets far enough away from the rest of it that it becomes its own distinct species, branch point on a phylogenic tree
Most recent common ancestor
At every branch point, the last animal that both species at the end of two different branches both descend from
Root
First line on a phylogenic tree, where all the species on it share their last most recent common ancestor
Relatedness
Measure of how recent two species' last common ancestor was
Polytomy
A branch point that has three or more different species coming off of it, showing that we don't have enough information to determine a more specific branching order