Population genetics

thumb|An example of the biodiversity of fungi in a forest in North Saskatchewan (in this photo, there are also leaf [[lichens and mosses).]]

The axolotl (; from ; Ambystoma mexicanum) is a species of paedomorphic mole salamander. They mature into their terrestrial adult form without undergoing metamorphosis; the adults remain fully aquatic with obvious external gills. This trait, although somewhat unusual among the majority of amphibians, is not unique. Axolotls may be difficult to distinguish from the larval stage of other neotenic adult mole salamanders, such as mudpuppies (Necturus spp.) or the occasionally paedomorphic tiger salamander (A. tigrinum).

offspring of cross-species reproduction

variation in the relative frequency of different genotypes in a small population

process by which humans use animal and plant breeding to selectively develop particular phenotypic traits

subfield of genetics that deals with genetic differences of populations, part of evolutionary biology

mode of natural selection

set of all genes in a population

transfer of genetic variation from one population to another

A haplotype is a group of alleles in an organism that are inherited together from a single parent, and a haplogroup (haploid from the , haploûs, "onefold, simple" and ) is a group of similar haplotypes that share a common ancestor with a single-nucleotide polymorphism mutation. More specifically, a haplotype is a combination of alleles at different chromosomal regions that are closely linked and tend to be inherited together. As a haplogroup consists of similar haplotypes, it is usually possible to predict a haplogroup from haplotypes. Haplogroups pertain to a single line of descent. Such as t

geographical area in which a taxon can be found

total number of genetic characteristics in the genetic makeup of a species

principle that allele and genotype frequencies in a population will remain constant over generations in the absence of other evolutionary influences

Exogamy is the social norm of mating or marrying outside one's social group. The group defines the scope and extent of exogamy, and the rules and enforcement mechanisms that ensure its continuity. One form of exogamy is dual exogamy, in which two groups continually intermarry with each other.

thumb|right|The passage of homozygous alleles through an inbred pedigree

quantitative representation of natural and sexual selection within evolutionary biology

tendency of DNA sequences that are close together on a chromosome to be inherited together

event that reduces size and genetic variation of a population, followed by a size recovery

Microevolution is the change in allele frequencies that occurs over time within a population. This change is due to four different processes: mutation, selection (natural and artificial), gene flow and genetic drift. This change happens over a relatively short (in evolutionary terms) amount of time compared to the changes termed macroevolution.

thumb|363px|DNA molecule 1 differs from DNA molecule 2 at a single base-pair location (a C/A polymorphism). A haplotype (haploid genotype) is a group of alleles in an organism that are inherited together from a single parent.

loss of genetic variation that occurs when a new population is established by a very small number of individuals

most recent individual from which all organisms in a group are directly descended

thumb|right|160px|Studies of heritability ask questions such as to what extent do genetic factors influence differences in height between people. This is not the same as asking to what extent do genetic factors influence height in any one person. Heritability is a statistic used in the fields of breeding and genetics that estimates the degree of variation in a phenotypic trait in a population that is due to genetic variation between individuals in that population. The concept of heritability can be expressed in the form of the following question: "What is the proportion of the variation in a g

relative frequency of a variant of a gene at a particular locus in a population

variation in the genome

proposed mechanism of evolution

thesis that most evolutionary changes occur at the molecular level, and that most of the variation within and between species are due to random genetic drift of mutant alleles that are selectively neutral

gradual variation of the characteristics of a species along its territory

reduced fitness as a result of inbreeding

ecological concept

Panmixia (or panmixis) means uniform random fertilization, which means individuals do not select a mate based on physical traits. A panmictic population is one where all potential parents may contribute equally to the gamete pool, and that these gametes are uniformly distributed within the gamete population (gamodeme). This assumes that there are no hybridising restrictions within the parental population: neither genetics, cytogenetics nor behavioural; and neither spatial nor temporal (see also Quantitative genetics for further discussion). True panmixia is rarely, if ever, observed in natural

Self-incompatibility (SI) is a general name for any genetic mechanism that prevents self-fertilization in fertile hermaphroditic organisms, and thus encourages outcrossing and allogamy. It is contrasted with separation of sexes among individuals (dioecy), and their various modes of spatial (herkogamy) and temporal (dichogamy) separation.

set of several similar genes

Biopiracy is the unauthorized appropriation of knowledge and genetic resources of farming and indigenous communities by individuals or institutions seeking exclusive monopoly control through patents or intellectual property. While bioprospecting is the act of exploring natural resources for undiscovered chemical compounds with medicinal or anti-microbial properties, commercial success from bioprospecting leads to the company's attempt at protecting their intellectual property rights on indigenous medicinal plants, seeds, genetic resources, and traditional medicines.

number of inhabitants of a given place

The non-random association of alleles at two or more genetic loci

explanation of human behaviour in terms of genetic and cultural evolution

similar DNA, RNA or protein sequences within genomes or among species

controversial term for uncontrolled dispersal of contaminated altered genes from genetically engineered organisms to natural organisms

Philopatry is the tendency of an organism to stay in or habitually return to a particular area. The causes of philopatry are numerous, but natal philopatry, where animals return to their birthplace to breed, may be the most common. The term derives from the Greek roots philo, "liking, loving" and patra, "fatherland", although in recent years the term has been applied to more than just the animal's birthplace. Recent usage refers to animals returning to the same area to breed despite not being born there, and migratory species that demonstrate site fidelity: reusing stopovers, staging points, a

concept in genealogy

irreversible accumulation of deleterious mutations in the absence of genetic recombination

process where the limited gene pool of an endangered species diminishes even more when reproductive individuals die off before reproducing with others in their endangered low population

evolutionary concept regarding the process between populations in the occupation of the same geographic range that leads to distinct species

generative statistical model that allows sets of observations to be explained by unobserved groups that explain why some parts of the data are similar

the degree to which a phenotype is expressed by individuals having a particular genotype

individuals of a particular species which are nearly identical to each other in genotype due to long inbreeding

theory that Ashkenazi Jews descended from Turkic Khazars

gene pool change in which one allele spreads to the whole population and all others die out

thumb|right|Klepton genetic inheritance in frogs In biology, a klepton (abbreviated kl.) and synklepton (abbreviated sk.) is a species that requires input from another biological taxon (normally from a species which is closely related to the kleptonic species) to complete its reproductive cycle. Specific types of kleptons are zygokleptons, which reproduce by zygogenesis; gynokleptons which reproduce by gynogenesis, and tychokleptons, which reproduce by a combination of both systems.

result of interbreeding between two or more previously isolated populations within a species

model of early human migration

selective removal of alleles that are deleterious

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mathematical estimate of inbreeding

model used to visualise relationship between genotypes and reproductive success

concept in genetics

measure of the degree of consanguinity (or biological relationship) between two individuals

model for tracing the history of genetic variation

subfield of population genetics that aims to understand the dynamics of genes in populations principally to avoid extinction