Evidence for Evolution and Biogeography

Flashcards covering key definitions and vocabulary on biogeography, continental drift, biological evolution, comparative anatomy, and Darwin's evolutionary theory.

Biogeography

The study of the distribution of existing (extant) and extinct plant and animal species in specific geographical regions.

Alfred Russel Wallace

A 19th-century British naturalist regarded as the founder of the modern science of biogeography.

Dispersal

The movement of populations away from their point of origin.

Mesosaurus

A freshwater reptile whose fossil remains were found in both South America and Africa, serving as fossil evidence of continental drift.

Cynognathus

A Triassic land reptile approximately $3\,\text{m}$ long whose fossil remains have been discovered in South America and Africa.

Glossopteris

A genus of fossil fern found in all southern continents, showing that they were once joined.

Biological Evolution

Genetic changes in a population over time that are inherited over generations due to natural selection, forming a new species.

Hypothesis

A statement that provides a proposed answer to a question of a specific scientific phenomenon based on evidence and observation, which can be tested in observations or experiments and accepted or rejected.

Theory

An explanation supported by facts, laws, and tested hypotheses, based on evidence, confirmed by different scientists, and capable of developing and changing as new evidence is found.

Population

A group of individuals of the same species that occupy the same habitat at the same time and can interbreed.

Species

One or more populations that have numerous physical features in common and can breed with one another to produce fertile offspring.

Speciation

The formation of new and distinct species in the course of evolution.

Cladogram

A branching diagram illustrating the evolutionary history of life forms and relationships between organisms, where distant ancestors appear at the base and recent ones make up branches or ends.

The Origin of Species

The landmark work published by Charles Darwin in 1859 presenting the first convincing case for evolution through natural selection.

HMS Beagle

The ship on which Charles Darwin embarked on a 5-year voyage around the world collecting plant and animal specimens and recording geographic notes.

Homology

Similarity of internal anatomical structure (such as the vertebrate limb skeleton) across different organisms, indicative of common ancestry.

Pentadactyl Limb

A 5-digit limb found in most vertebrates possessing the same general bone structure, modified across different taxa for specialized functions.

Homologous Structures

Body structures sharing the same basic skeletal or anatomical plan but modified to serve different functions in different environments.

Adaptive Radiation (Divergent Evolution)

The evolutionary adaptation of a common basic body or limb plan into different functional forms to exploit various ecological niches.

Analogous Structures

Structures that perform the same function in different organisms but do not share a common evolutionary origin.

Convergent Evolution

The evolutionary process where anatomically distinct structures independently develop similar functions as an adaptation to similar environments.

Vestigial Organs

Structures that serve no apparent purpose in an organism but provide clues to its evolutionary history, such as the pelvic bone in whales and the human coccyx or appendix.

Darwin's Tubercle

A vestigial feature on the human ear associated with muscles that fail to develop the mobility found in monkeys.