Evolution, Speciation, and Taxonomy - Key Terms

A vocabulary set of key evolutionary concepts, taxonomic terms, and phylogenetic notions covered in the lecture.

Evolution

Gradual changes in the composition and diversity of a population over generations; the process that generates change and diversity.

Microevolution

Small-scale evolutionary changes within a population over a few generations (allele frequency shifts).

Macroevolution

Evolution over long time scales that leads to new species and higher taxa.

Population

A group of interbreeding individuals of the same species in a given area; unit of evolution for microevolution.

Mutation

Copying error in DNA replication introducing heritable variation; occurs continually.

Genetic drift

Random changes in allele frequencies due to chance, not selection.

Natural selection

Differential survival and reproduction based on heritable traits; drives adaptation.

Speciation

Process by which one population splits into two or more distinct species.

Isolation

Condition where gene flow is reduced or blocked between populations, enabling independent evolution.

Geographic isolation

Physical barriers (rivers, mountains, distances) split populations.

Behavioral isolation

Differences in mating signals or behaviors prevent interbreeding.

Temporal isolation

Differences in timing of reproduction prevent interbreeding.

Habitat isolation

Preference for different habitats within the same environment reduces mating opportunities.

Adaptive radiation

Rapid diversification into many species occupying different ecological roles after colonization of new habitats (often islands).

Mass extinction

Widespread, rapid extinction event that prunes branches of the tree of life.

Common ancestor

An ancestral species from which two or more lineages diverged.

Biological species concept

A species is a reproductively isolated group of organisms that interbreed within the group but not with others.

Phylogenetics

Study of evolutionary relationships using diagrams (phylogenetic trees) showing ancestry.

Systematics

Science of classifying organisms and organizing their relationships into a nested hierarchy.

Binomial nomenclature

Two-name naming system for species (genus + species).

Linnaeus

Carl Linnaeus, founder of binomial nomenclature and modern taxonomy.

Genus

First part of a binomial name; a group of closely related species.

Species

Second part of a binomial name; the basic unit of classification; unique within a genus.

Homo sapiens

Modern human species; genus Homo, species sapiens.

Hominidae

Family including humans and the great apes.

Mammalia

Class of mammals; characterized by features like mammary glands, hair, and three middle ear bones.

Chordata

Phylum including animals with a notochord; includes all vertebrates.

Animalia

Kingdom containing all animals.