Search results
Results From The WOW.Com Content Network
The study of human genetic variation has evolutionary significance and medical applications. It can help scientists reconstruct and understand patterns of past human migration. In medicine, study of human genetic variation may be important because some disease-causing alleles occur more often in certain population groups.
Genetic variation can be identified at many levels. Identifying genetic variation is possible from observations of phenotypic variation in either quantitative traits (traits that vary continuously and are coded for by many genes, e.g., leg length in dogs) or discrete traits (traits that fall into discrete categories and are coded for by one or a few genes, e.g., white, pink, or red petal color ...
Island Population: The marine iguana is an endemic species of the Galapagos Islands, but it evolved from a mainland ancestor of land iguana. Due to geographic isolation gene flow between the two species was limited and differing environments caused the marine iguana to evolve in order to adapt to the island environment.
This is due to a need for an increased exposure and absorbance of sunlight to make sure the body can produce enough vitamin D for survival. [2] Blackfoot disease is a disease caused by environmental pollution and causes people to have black, charcoal-like skin in the lower limbs. This is caused by arsenic pollution in water and food source. [3]
Population structure commonly arises from physical separation by distance or barriers, like mountains and rivers, followed by genetic drift. Other causes include gene flow from migrations, population bottlenecks and expansions, founder effects, evolutionary pressure, random chance, and (in humans) cultural factors. Even in lieu of these factors ...
Genetic drift is a change in allele frequencies caused by random sampling. [40] That is, the alleles in the offspring are a random sample of those in the parents. [41] Genetic drift may cause gene variants to disappear completely, and thereby reduce genetic variability.
This is an accepted version of this page This is the latest accepted revision, reviewed on 15 February 2025. Science of genes, heredity, and variation in living organisms This article is about the general scientific term. For the scientific journal, see Genetics (journal). For a more accessible and less technical introduction to this topic, see Introduction to genetics. For the Meghan Trainor ...
Genetic variance is a concept outlined by the English biologist and statistician Ronald Fisher in his fundamental theorem of natural selection. In his 1930 book The Genetical Theory of Natural Selection, Fisher postulates that the rate of change of biological fitness can be calculated by the genetic variance of the fitness itself. [1]