Evidence for Evolution

Vocabulary flashcards covering the four lines of evidence for evolution: direct observations, homologies, the fossil record, and biogeography.

Direct observations of evolutionary change

One of four main categories of data documenting evolution, directly observed in species with short generation times such as Galápagos finches, peppered moths, soapberry bugs, and drug-resistant bacteria.

Homology

Similarity among different organisms resulting from common ancestry.

Homologous structures

Anatomical resemblances that represent variations on a structural theme inherited from a common ancestor, such as mammalian forelimbs.

Homologous embryonic structures

Anatomical similarities revealed through comparative embryology that are not visible in adult organisms, such as pharyngeal arches and a post-anal tail present in all vertebrate embryos.

Vestigial structures

Remnants of features that served important functions in an organism's ancestors, such as pelvic and leg bone vestiges in snakes or eye remnants in blind cave fishes.

Molecular homologies

Shared molecular traits inherited from a common ancestor, such as shared genes and a universal genetic code used to translate RNA into proteins.

Soapberry bug beak evolution

An example of rapid natural selection where soapberry bug beak lengths evolved in central Florida in less than 35 years in response to feeding on the smaller fruits of the introduced golden rain tree compared to the native balloon vine.

Methicillin-resistant Staphylococcus aureus (MRSA)

A dangerous pathogenic bacterial strain that evolved resistance to penicillin in 1945 (two years after wide use) and to methicillin in 1961 (two years after wide use).

Fossil record

A dataset that provides historical evidence of evolution by documenting the extinction of species, the origin of new groups, and structural changes within groups over time.

Transitional fossils

Fossils that serve as 'missing links' by documenting intermediate stages in the evolutionary histories of living taxa, such as the land-to-sea transition in cetaceans.

Chronological sequence

The order of appearance of different taxa in the fossil record, which aligns with their branching order in phylogenetic trees.

Biogeography

The study of the geographic distribution of species, which shows how geographic isolation and environmental factors shape species diversity.

Pangaea

The single large landmass that formerly united all of Earth's continents before they broke apart due to continental drift.

Marsupial biogeography

The modern distribution pattern of marsupials, which diverged from eutherian mammals approximately 90 million years ago and are found almost exclusively in Australia due to continental drift and geographic isolation.