Phylogeny and the Tree of Life

These flashcards cover key vocabulary related to phylogeny, classification, and evolutionary relationships based on the provided lecture notes.

Phylogenetic Tree

A diagram that represents hypotheses about evolutionary relationships among species, showing how species are related through common ancestors.

Phylogeny

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

Systematics

The scientific discipline that classifies organisms and determines their evolutionary relationships.

Homology

Phenotypic and genetic similarities that are due to shared ancestry, indicating close evolutionary relationships.

Analogy

Similarity between characteristics of different species that is not due to shared ancestry but rather to convergent evolution.

Clade

A group of species that includes an ancestral species and all its descendants, indicating common evolutionary history.

Monophyletic Group

A taxonomic grouping that includes an ancestor and all of its descendants.

Paraphyletic Group

A taxonomic grouping that consists of an ancestor and some, but not all, of its descendants.

Polyphyletic Group

A taxonomic grouping that includes distantly related species but does not include their most recent common ancestor.

Binomial Nomenclature

A two-part scientific naming system for species, consisting of the genus name and specific epithet.

Fossil Record

Historical evidence preserved in rock layers that gives insight into the evolutionary history and characteristics of organisms.

Homoplasies

Similar traits that arise independently in different species, often due to similar environmental pressures.

Outgroup

A species or group of species that is closely related to the ingroup but diverged before the ingroup.

Molecular Clock

A method that uses molecular changes (like DNA mutations) to estimate the time of evolution between species.

Orthologous Genes

Genes in different species that evolved from a common ancestral gene by speciation.

Paralogous Genes

Genes that are related by duplication within a genome and can evolve new functions.