Differential success in the reproduction of different phenotypes resulting from the interaction of organisms with their environment. Evolution occurs when natural selection causes changes in relative frequencies of alleles in the gene pool.
result of natural selection, a prevalence of inherited characteristics that enhance organism's survival and reproduction in specific environments
All the changes that have transformed life on Earth from its earliest beginnings to the diversity that characterizes it today.
A philosophy dedicated to discovering the Creator's plan by studying nature. Adaptations of organisms are viewed as evidence that the Creator had designed each and every species for a particular purpose.
The branch of biology concerned with naming and classifying the diverse forms of life. <Linnaeus>
A preserved remnant or impression of an organism that lived in the past.
Rock formed from sand and mud that once settled in layers on the bottom of seas, lakes, and marshes. Sedimentary rocks are often rich in fossils.
The scientific study of fossils.
The hypothesis by Georges Cuvier that each boundary between strata corresponded in time to a catastrophe, such as a flood or drought, that had destroyed many of the species living there at that time.
A view of Earth's history that attributes profound change to the cumulative product of slow but continuous processes. <Hutton>
Charles Lyell's idea that geologic processes have not changed throughout Earth's history.
descent with modification
Darwin's initial phrase for the general process of evolution.
The selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits.
Similarity in characteristics resulting from a shared ancestry.
Structures in different species that are similar because of common ancestry.
Structures of marginal, if any, importance to an organism. They are historical remnants of structures that had important functions in ancestors.
The study of the past and present distribution of species.
The study of genetic changes in populations; the science of microevolutionary changes in populations.
A comprehensive theory of evolution emphasizing natural selection, gradualism, and populations as the fundamental units of evolutionary change; also called neo-Darwinism.
A group of individuals of one species that live in a particular geographic area.
A group whose members possess similar anatomical characteristics and have the ability to interbreed.
The total aggregate of genes in a population at any one time.
hardy weinberg equilibrium
The condition describing a non-evolving population (one that is in genetic equilibrium).
hardy weinberg theorem
An axiom maintaining that the sexual shuffling of genes alone cannot alter the overall genetic makeup of a population.
hardy weinberg equation
A formula for calculating the frequencies of genotypes in a gene pool from the frequencies of alleles, and vice versa.
A change in the gene pool of a population from generation to generation.
Changes in the gene pool of a small population due to chance.
Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer genetically representative of the original population.
Genetic drift attributable to colonization by a limited number of individuals from a parent population.
The loss or gain of alleles in a population due to the migration of fertile individuals or gametes between populations.
Referring to a population in which two or more physical forms are present in readily noticeable frequencies.
measures the average percentage of gene loci that are heterozygous
Differences in genetic structure between populations.
Graded variation in some traits of individuals that parallels a gradient in the environment.
The ability of natural selection to maintain diversity in a population.
Greater reproductive success of heterozygous individuals compared to homozygotes; tends to preserve variation in gene pools.
frequency dependent scale
A decline in the reproductive success of a morph resulting from the morph's phenotype becoming too common in a population; a cause of balanced polymorphism in populations.
Genetic diversity that confers no apparent selective advantage.
The contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals.
The contribution of one genotype to the next generation compared to that of alternative genotypes for the same locus.
Natural selection that favors individuals at one end of the phenotypic range.
Natural selection that favors intermediate variants by acting against extreme phenotypes.
A special case of polymorphism based on the distinction between the secondary sex characteristics of males and females.
A direct competition among individuals of one sex (usually the males in vertebrates) for mates of the opposite sex.
Individuals of one sex (usually females) are choosy in selecting their mates from individuals of the other sex, also called mate choice.
Natural selection that favors opposite extreme over intermediate phenotypes.