AP Bio Chapter 25 Phylogeny and Systematics

37 terms by ZehraAleena Plus

Create a new folder

Like this study set?

Create a free Quizlet account to save it and study later.

Sign up for an account

Already have a Quizlet account? .

Create an account

Advertisement Upgrade to remove ads


The evolutionary history of a species or group of related species.


The analytical study of the diversity and relationships of organisms, both present-day and extinct.

Molecular Systematics

The comparison of nucleic acids or other molecules in different species to infer relatedness.

Fossil Record

The chronicle of evolution over millions of years of geologic time engraved in the order in which fossils appear in rock strata.


Similarity between two species that is due to convergent evolution rather than to descent from a common ancestor with the same trait.


Similar (analogous) structure or molecular sequence that has evolved independently in two species.


Ordered division of organisms into categories based on a set of characteristics used to assess similarities and differences, leading to a classification scheme; the branch of biology concerned with naming and classifying the diverse forms of life.


The two-part latinized name of a species, consisting of genus and specific epithet.


A taxonomic category above the species level, designated by the first word of a species′ two-part scientific name.

Specific Epithet

The second part of a binomial, referring to one species within a genus.


In classification, the taxonomic category above genus.


In classification, the taxonomic category above family.


In classification, the taxonomic category above order.


In classification, the taxonomic category above class.


A taxonomic category, the second broadest after domain


A taxonomic category above the kingdom level. Archaea, Bacteria, and Eukarya.


The named taxonomic unit at any given level of classification.

Phylogenetic Tree

A branching diagram that represents a hypothesis about evolutionary relationships.


A diagram depicting patterns of shared characteristics among species.


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


The analysis of how species may be grouped into clades


Pertaining to a grouping of species consisting of an ancestral species and all its descendants; a clade. Made up of an ancestral species and all of its descendant species.


Pertaining to a grouping of species that consists of an ancestral species and some, but not all, of its descendants.


Pertaining to a grouping of species derived from two or more different ancestral forms.

Shared Primitive Character

A character displayed in species outside a particular taxon.

Shared Derived Character

A character that is unique to a particular taxon

Outgroup Comparison

Used to differentiate between shared derived characters and shared primitive characters.


A species or group of species that is closely related to the group of species being studied, but clearly not as closely related as any study-group members are to each other


In a cladistic study of evolutionary relationships among taxa of organisms, the group of taxa that is actually being analyzed


A phylogenetic tree in which the lengths of the branches reflect the number of genetic changes that have taken place in a particular DNA or RNA sequence in the various lineages

Ultrametric Tree

A phylogenetic tree in which the lengths of the branches reflect measurements of geologic time.

Maximum Parsimony

A principle that states that when considering multiple explanations for an observation, one should first investigate the simplest explanation that is consistent with the facts.

Maximum Likelihood

A principle that states that when considering multiple phylogenetic hypotheses, one should take into account the one that reflects the most likely sequence of evolutionary events, given certain rules about how DNA changes over time.

Orthologous Genes

Homologous genes that are passed in a straight line from one generation to the next, but have ended up in different gene pools because of speciation.

Paralogous Genes

Homologous genes that are found in the same genome due to gene duplication.

Molecular Clock

An evolutionary timing method based on the observation that at least some regions of genomes evolve at constant rates.

Neutral Theory

The hypothesis that much evolutionary change in genes and proteins has no effect on fitness and therefore is not influenced by Darwinian natural selection.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set