History of Evolutionary Thought

allele frequency

rate at which a specific allele appears within a population

Georges Cuvier

paleontologist that was first to formally recognize extinction

evolution

change in allele frequencies of a population across generations

fitness

individual’s ability to survive and reproduce (see also relative fitness)

fossil

the preserved remains (body fossils) or traces (trace fossils) of organisms from prehistoric time

homology

similarity between species due to inheritance from a common ancestor

James Hutton

geologist that proposed that geological change occurs gradually by accumulating small changes from processes like erosion and uplift

Jean Baptiste de Lamarck

proposed inheritance of acquired characteristics as the mechanism for evolution. Although the theory was flawed, it was an important step toward describing how evolution could occur

Law of Superposition

layers of rock are arranged in time sequence with younger layers near top

Charles Lyell

geologist that shared the gradualism view of Hutton, played role in joint publication theory of natural selection

Macroevolution

broader scale evolutionary changes that scientists see over paleontological time

malthusian catastrophe

occurs when population size exceeds resource availability, leading to intense competition and crash of population size

Gregor Mendel

geneticist that first described many characteristics of heredity

microevolution

changes in a population’s genetic structure over short time scales (as little as one generation to next)

modern synthesis

overarching evolutionary paradigm that took shape by the 1940s and scientists generally accept today

Nicholas Steno

first to formally recognize that fossils are the remains of organisms

transitional feature

trait i a fossil that is intermediate between ancestral (older) and derived (newer) species

vestigal structure

physical structure present in an organism but has no (or little) apparent function and appears to be from a functional structure in a distant ancestor

Alfred Russel Wallace

conceived and described (independently with Charles Darwin) natural selection as a mechanism for evolution

permineralization

fossilization process in which minerals enter dead organic material and forms an internal cast