Phylogeny and the Tree of Life

These flashcards cover key vocabulary terms and definitions related to phylogeny and the tree of life, aiming to help students understand and remember important concepts for their exam.

Phylogeny

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

Systematics

The discipline that classifies organisms and determines their evolutionary relationships.

Taxonomy

The ordered division and naming of organisms.

Binomial Nomenclature

A two-part scientific naming system introduced by Carolus Linnaeus.

Taxon

A taxonomic unit at any level of hierarchy.

Hierarchical Classification

A system for grouping species in increasingly broad categories.

Clade

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

Monophyletic Group

A valid clade consisting of an ancestor species and all its descendants.

Paraphyletic Group

A grouping that consists of an ancestral species and some of its descendants.

Polyphyletic Group

A grouping that consists of various species that lack a common ancestor.

Homology

Similarity due to shared ancestry.

Analogy

Similarity due to convergent evolution.

Convergent Evolution

When similar environmental pressures produce similar adaptations in unrelated organisms.

Morphological Data

Data related to the structure and form of organisms used to infer phylogenetic relationships.

Molecular Data

DNA and other molecular data used to determine evolutionary relationships.

Cladistics

A method of classification based on common descent.

Shared Ancestral Character

A characteristic that originated in an ancestor of the taxon.

Shared Derived Character

An evolutionary novelty unique to a particular clade.

Molecular Systematics

The use of DNA and molecular evidence to determine evolutionary relationships.

Maximum Parsimony

A principle that suggests the simplest tree explaining the data is the most likely.

Molecular Clock

A method that uses mutation rates to estimate the time of evolutionary change.

Horizontal Gene Transfer

The movement of genetic material between organisms that are not directly related.

Orthologous Genes

Genes found in a single copy in the genome, homologous between species.

Paralogous Genes

Genes that are found in multiple copies in the genome due to gene duplication.

Gene Duplication

The process by which a gene is copied in the genome, leading to multiple gene copies.

Phylogenetic Tree

A branching diagram that represents the evolutionary relationships among species.

Sister Taxa

Groups that share an immediate common ancestor.

Ancestral Lineage

The lineage from which a taxon is derived, including its ancestors.

Homoplasies

Analogous structures or sequences that evolved independently.

Morphological and Molecular Data

The combination of structure and genetic information used to infer phylogenies.

PhyloCode

A code that defines groups based on common ancestry and descendent species.

Phylogenetic Bracketing

Predicting features of an ancestor based on its descendents' features.

Phylogeny and Character Evolution

The study of how traits evolve within the context of evolutionary history.

Difficulties with Molecular Clocks

Irregularities arise from natural selection affecting mutation rates.