Taxonomy and Evolutionary Relationships in Biology

Taxonomy

International classification system for naming organisms.

Linnaean System

Taxonomic classification system developed by Carl Linnaeus.

Taxon

Each individual group within the taxonomic hierarchy.

Binomial nomenclature

Two-part naming system: Genus and species.

Genus

First part of binomial nomenclature, capitalized.

Species

Second part of binomial nomenclature, lowercase.

Eukarya

Domain including all eukaryotic organisms.

Animalia

Kingdom comprising all animals.

Chordata

Phylum including animals with a notochord.

Mammalia

Class of warm-blooded vertebrates with hair.

Carnivora

Order of carnivorous mammals.

Felidae

Family of cats, including big and domestic cats.

Speciation

Process where one lineage diverges into separate lineages.

Phylogenetic tree

Diagram showing evolutionary relationships among species.

Homologies

Similar traits due to shared ancestry.

Analogies

Similar traits due to environmental pressures.

Convergent evolution

Evolution of similar traits in unrelated lineages.

Divergent evolution

Differentiation of a lineage into distinct forms.

Apomorphy

Novel derived character unique to a group.

Synapomorphy

Shared derived character from a common ancestor.

Autapomorphy

Unique derived character not present in ancestors.

Plesiomorphy

Ancestral character shared by ancestor and descendants.