Phylogeny: The Tree of Life

These flashcards cover key vocabulary and concepts related to phylogeny and the classification of species, as discussed in the lecture videos.

Phylogeny

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

Systematics

The discipline focused on classifying organisms and determining their relationships.

Taxonomy

The study of the classification of life.

Binomial Nomenclature

A system of naming species with two-part names, the genus and the species.

Carolus Linnaeus

The scientist who developed the binomial nomenclature system in the 18th century.

Taxon

Each category in the hierarchical classification of species.

Hierarchical Classification

A system where species are grouped by increasingly smaller categories based on similarity.

Domain

The highest taxonomic rank, which groups all living organisms.

Kingdom

A taxonomic category below domain but above phylum.

Phylum

A taxonomic category that classes organisms based on major body plans.

Class

A taxonomic category that is a subdivision of phylum.

Order

A taxonomic rank used in the classification of organisms.

Family

A group of related genera.

Genus

The taxonomic category that is one level above species.

Species

The basic unit of classification, a group of organisms that can interbreed.

Phylogenetic Tree

A diagram representing the evolutionary history and relationships among various species.

Sister taxa

Groups that share a unique common ancestor in a phylogenetic tree.

Branching point

The point in a phylogenetic tree where a lineage diverges into two lineages.

Ancestral traits

Traits that are inherited from a common ancestor.

Derived traits

Evolutionary novelties unique to a particular clade.

Homologous structures

Anatomical features that are similar due to shared ancestry.

Analogous structures

Anatomical features that are similar due to convergent evolution, not ancestry.

Cladistics

A method of classifying organisms based on common ancestry.

Clade

An ancestral species and all its descendants.

Monophyletic

A group that includes an ancestor and all its descendants.

Paraphyletic

A group that includes an ancestor but not all of its descendants.

Polyphyletic

A group that includes species with different ancestors.

Maximum parsimony

A method for analyzing phylogenies that assumes the simplest explanation or fewest changes is the best.

Maximum likelihood

A method that uses statistical models to determine the most probable phylogenetic tree.

Molecular clock

A method that estimates the timing of evolutionary divergences based on mutation rates.

Homologous Genes

Genes that are similar due to shared ancestry.

Orthologous genes

Homologous genes that are found in different species due to speciation.

Paralogous genes

Homologous genes that result from gene duplication within a species.

Gene duplication

The process by which a gene is copied, leading to more opportunities for evolutionary change.

Morphological data

Features such as shape and structure used to infer phylogenetic relationships.

DNA analysis

The study of genetic material in organisms used to determine relationships.

Gene families

Groups of related genes that have diverged from a common ancestor.

Homology

Similarity in characteristics due to shared ancestry.

Analogy

Similarity in traits due to convergent evolution rather than shared ancestry.

Introgressive hybridization

Gene flow through reproduction between different species or populations.

Horizontal Gene Transfer

The transfer of genes between organisms other than through traditional reproduction.

Extinct species

Species that no longer exist.

Fossil record

The history of life documented by fossils.

Common ancestor

An ancestral species from which multiple species descend.

Phylogenetic bracketing

The prediction of traits shared by species based on their common ancestry.

Phylogenetic tree structure

The arrangement of branches and taxa in a phylogenetic tree.

Mitochondrial DNA

Genetic material found in mitochondria, which evolves rapidly and helps study recent evolutionary events.

Nucleotide substitutions

Changes in the DNA sequence that can be used to estimate evolutionary divergence.