Population genetics

The genetic history of indigenous peoples of the Americas primarily focuses on Human Y-chromosome DNA haplogroups and Human mitochondrial DNA haplogroups.

Genetic drift (also known as allelic drift or the Sewall Wright effect after biologist Sewall Wright) is the change in the frequency of a gene variant (allele) in a population due to random sampling of organisms.

The archaeogenetics of the Near East is the study of the genetics of past human populations (archaeogenetics) in the Ancient Near East using DNA from ancient remains.

The study of the genetics and archaeogenetics of the ethnic groups of South Asia aims at uncovering these groups' genetic history.

Life timelineview • discuss • -4500 —–-4000 —–-3500 —–-3000 —–-2500 —–-2000 —–-1500 —–-1000 —–-500 —–0 —waterSingle-celledlifephotosynthesisEukaryotesMulticellularlifeLand lifeDinosaurs MammalsFlowers ←Earliest Earth (-4540)←Earliest water←Earliest life(-4100)←LHB meteorites←Earliest oxygen←Atmospheric oxygen←Oxygen Crisis←Earliest sexual reproduction←Cambrian explosion←Earliest humansPhanrzcProterozoicArcheanHadeanAxis scale: millions of years.

In population genetics and population ecology, population size (usually denoted N) is the number of individual organisms in a population.

The axolotl (/ˈæksəlɒtəl/, from Classical Nahuatl: āxōlōtl [aː.ˈʃóː.loːtɬ]) also known as a Mexican salamander (Ambystoma mexicanum) or a Mexican walking fish, is a neotenic salamander, closely related to the tiger salamander.

Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species.

Horizontal gene transfer (HGT) is the movement of genetic material between unicellular and/or multicellular organisms other than via vertical transmission (the transmission of DNA from parent to offspring.) HGT is synonymous with lateral gene transfer (LGT) and the terms are interchangeable.

Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically.

Microevolution is the change in allele frequencies that occurs over time within a population.

The neutral theory of molecular evolution holds that at the molecular level most evolutionary changes and most of the variation within and between species is not caused by natural selection but by genetic drift of mutant alleles that are neutral.

A population bottleneck (or genetic bottleneck) is a sharp reduction in the size of a population due to environmental events (such as earthquakes, floods, fires, disease, or droughts) or human activities (such as genocide).

Sexual dimorphism is the condition where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs.

In evolutionary ecology, an ecotype, sometimes called ecospecies, describes a genetically distinct geographic variety, population or race within a species, which is adapted to specific environmental conditions.

Heritability is a statistic used in breeding and genetics works that estimates how much variation in a phenotypic trait in a population is due to genetic variation among individuals in that population.

The genetic history of Europe is complicated because European populations have a complicated demographic history, including many successive periods of population growth.

A unit of selection is a biological entity within the hierarchy of biological organization (for example, an entity such as: a self-reproducing molecule, a gene, a cell, an organism, a group, or a species) that is subject to natural selection.

Genetic erosion is a process whereby an already limited gene pool of an endangered species of plant or animal diminishes even more when individuals from the surviving population die off without getting a chance to meet and breed with others in their endangered low population.

In population genetics, F-statistics (also known as fixation indices) describe the statistically expected level of heterozygosity in a population; more specifically the expected degree of (usually) a reduction in heterozygosity when compared to Hardy–Weinberg expectation.

Species distribution is the manner in which a biological taxon is spatially arranged.

The Khazar hypothesis of Ashkenazi ancestry, often called by its critics the "Khazar myth", is the hypothesis that Ashkenazi Jews are descended from the Khazars, a multi-ethnic conglomerate of Turkic peoples who formed a semi-nomadic Khanate in the area extending from Eastern Europe to Central Asia.