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37 terms

AP Bio Chapter 25 Phylogeny and Systematics

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Phylogeny
The evolutionary history of a species or group of related species.
Systematics
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.
Analogy
Similarity between two species that is due to convergent evolution rather than to descent from a common ancestor with the same trait.
Homoplasy
Similar (analogous) structure or molecular sequence that has evolved independently in two species.
Taxonomy
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.
Binomial
The two-part latinized name of a species, consisting of genus and specific epithet.
Genus
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.
Family
In classification, the taxonomic category above genus.
Order
In classification, the taxonomic category above family.
Class
In classification, the taxonomic category above order.
Phylum
In classification, the taxonomic category above class.
Kingdom
A taxonomic category, the second broadest after domain
Domain
A taxonomic category above the kingdom level. Archaea, Bacteria, and Eukarya.
Taxon
The named taxonomic unit at any given level of classification.
Phylogenetic Tree
A branching diagram that represents a hypothesis about evolutionary relationships.
Cladogram
A diagram depicting patterns of shared characteristics among species.
Clade
A group of species that includes an ancestral species and all its descendants.
Cladistics
The analysis of how species may be grouped into clades
Monophyletic
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.
Paraphyletic
Pertaining to a grouping of species that consists of an ancestral species and some, but not all, of its descendants.
Polyphyletic
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.
Outgroup
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
Ingroup
In a cladistic study of evolutionary relationships among taxa of organisms, the group of taxa that is actually being analyzed
Phylogram
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.