Evolution Unit Review

Flashcards about evolution

Genetic drift

Random changes in allele frequencies in a population

Convergent evolution

Similar traits evolving in unrelated species

Allopatric speciation needs…

Geographic isolation

Development of similar traits in species that do not share a recent common ancestor

Convergent evolution

Adaptation

Increasing reproductive success (fitness) in a given environment. Structural, behavioral, or physiological process that helps an organism survive and reproduce in a particular environment

Genetic drift mainly influences

Small populations

Rapid diversification of a common ancestor into a wide variety of forms

Adaptive radiation

Mutations in the context of evolution

Mutations provide variation for natural selection to act upon

Gene flow

Movements of alleles from one population of a species to another population as a result of the migration (groups from different areas breed and add new genes to the population) exchange of genetic material between populations.

Lyell

He revolutionized the ideas about the Earth; on how the Earth changed and continues to change

Linnaeus

One of the first to propose the idea that species can change and even may have come from a common ancestry

Charles Darwin

He collected and studied organisms from South America and the surrounding islands; came up with a theory of evolution

Lamarck

He proposed the inheritance of acquired traits: introduced the role of environment in evolutionary change

Analogous Structures

Structures similar in function but do not share a common ancestor

Homologous Structures

Structures that share common origin but may serve different functions in modern species

Vestigial Features

Non functioning structures that are present in reduced form → function in a past ancestor that provide evidence of evolution and common ancestry.

Selective advantage

A genetic advantage that improves organisms chance of survival

Fitness

the ability of an individual to survive and reproduce in its environment

Reproductive isolating mechanism

A barrier that prevents two populations from interbreeding

Ecological isolation

Species occupy different habitats so won’t breed

Mechanical isolation

Reproductive “parts” don’t fit

Divergent evolution

One ancestral species evolves into multiple different modern day species due to the exposure of different selective pressures

Convergent evolution

Unrelated ancestral species are exposed to the same selective pressures, which leads to similar structural adaptations

Allopatric speciation

A geographic barrier is introduced into a population

Sympatric speciation

Portions of a population will speciate within the same geographic area, without isolation

Fossil record support for evolution

Provides a timeline of the history of life on Earth and shows the gradual changes that have occurred over time.

Sexual selection

A mechanism that reduces variation, or selects for/against certain traits in a species based on it’s influence on mating success

Habitat fragmentation impact on evolution

Initially there will be more genetic drift (bottleneck e ect) due to the small population

Artificial selection impact on evolution

Traits that are desirable to human breeders will be the ones that increase in the population over time