Evolution Flashcards

Flashcards about Evolution

Evolution

A process through which allele and genotype frequencies change over time in a population.

Inheritance of acquired characteristics

An individual could change or be modified based on the environment in which it lives, and these changes would be inherited by its offspring.

Natural Selection

Species change over time, and a mechanism to explain how and why such changes occur.

Outcome of Natural Selection

Offspring with inherited characteristics that allow them to best compete for limited resources would be able to survive and have more offspring than individuals with other variations.

Variation

Differences among individuals in a population.

Mutation

A change in DNA, it is the ultimate source of new genetic variation in any population.

Adaptation

A heritable trait that aids the survival and reproduction of an organism in its present environment becomes more frequent in a population.

Divergent evolution

When two species evolve in different directions from a common point.

Convergent evolution

Similar structures arise through evolution independently in different species.

The modern synthesis

Describes how evolutionary pressures affect a population’s genetic makeup, integrates the theory of evolution with genetics, and allows for small genetic changes in a population over time.

Microevolution

Small genetic changes in a population over time.

Macroevolution

Major evolutionary events that cause significant changes in a population over time.

Speciation

The formation of two species from one original species.

Allopatric speciation

Geographically separated populations evolve independently until they can no longer interbreed.

Sympatric speciation

Speciation occurs within a single population of a parent species, in one location.

Population genetics

The study of what happens to the alleles in a population over time.

Gene pool

All of the alleles in a population.

Hardy-Weinberg equilibrium

A population’s allele and genotype frequencies will remain the same unless some kind of evolutionary force acts upon the population.

Natural selection

Selects for beneficial alleles that allow for environmental adaptation.

Artificial selection

Humans determine the fitness of individuals in a population based on their traits.

Sexual selection

Fitness of certain traits is determined by different levels of reproductive success due to mate choice.

Genetic drift

A change in a population’s allele or genotype frequencies due to random chance.

Bottleneck effect

A disaster randomly kills a large portion of a population.

Founder effect

A portion of a population leaves to start a new population in a new location, or if a population gets divided by a physical barrier of some kind.

Gene flow

The movement of alleles into and/or out of a population.

Fossils

Mineralized, or preserved, remains of organisms from the past.

Homologous structures

While being superficially different, have a similar pattern or layout due to being inherited from a common ancestor.

Vestigial structures

Have no apparent function in current species, yet are evidence of descent from an ancestor species with that structure.

Embryology

The study of an organism’s development from a zygote to its adult form.

Evolution is just a theory

Critics of evolution say there is little evidence supporting it and that it is still in the process of being rigorously tested.

Individuals Evolve

Individuals are born with a specific set of genes and these genes do not change as the individual ages, so individuals cannot evolve, populations evolve.

Evolution explains the origin of life

Explains how populations change over time and how life diversifies, not how life came to exist.

Organisms evolve on purpose

Disregarding mutations, the mechanisms of evolution act on variation that already exists in a population, variation does not arise in response to organism’s needs or wants.

Evolution is thought to be controversial among scientists

Evolution is nearly universally accepted among biologists today due to the overwhelming body of evidence supporting it.