Genetic Structure and Differentiation of Four Populations of Afghan Pika (Ochotonarufescens) based on mitochondrial cytochrome b gene in Iran

From the data we can conclude that different traits or parameters can effect a population in many different ways. It can decrease or increase a population depending on the trait. After a hurricane hits Lake Malawi the cichlid fish male population must adapt to the new factors that have been put upon them. Mutation within the population supports the fact that it can cause dominant and recessive allele frequency to decrease. Migration causes the allele frequency to lower as well due to movement of the population after the hurricane. The cichlid male fish with a higher fitness are more suitable for their environment, but when their fitness is lowered, their allele frequency decreases. This

A. Rus hoelze et al, studied the impact of intense hunting of Northern Elephant Seals in the late 19th century, whose genetic variation reduced due to this bottleneck. This reduced their population size to just about 20. They found that although it has since rebounded to over 30K now but compared to their southern counterparts i.e., Southern Elephant Seals they have much less genetic variation. The Southern Elephant Seals didn’t went through this bottleneck event. It is clear that the genes of Northern Elephant Seals still carrying the marks of this bottleneck.

Loss of genetic diversity in natural populations has often been attributed to a severe reduction in population size. Testing of nine loci in three heavily fished areas concluded that all loci that were strongly polymorphic in the 1982 study showed a reduction in heterozygosity with the exception of one

Gene flow: genetic additions and/or subtractions from a population resulting from the movement of gametes

In a large, randomly mating population where mutations, migration, and natural selection are no longer viable, the allele and genotypic frequencies will remain at equilibrium. If any of these conditions are changed, then the allele and genotype frequencies will be unable to maintain genetic equilibrium.

In the Peconic River, biodiversity is an vital aspect of the environment which eminently contributes to the net productivity of the ecosystem. The greater the total amount of genetic diversity within a specific population, the larger the complete range of genetic traits a population will possess. In unfortunate cases such as natural disasters, a more diverse ecosystem possesses a higher probability to recover and flourish, since more individuals will have the attributes required to survive the cataclysm. Overall, as the gene pool diversity steadily increases, the gamble of inbreeding and genetic defects decreases. This is an example of a prominent part in the journey to extinction and is often seen in endangered species who have difficulty

Variation in allele frequency through time will be the net result of colonizing and extinction processes in the population. In other words, while species abundance in the population may remain stable over time, genetic diversity may vary (Figure 1). For instance, we would expect populations at earlier stages of establishment to exhibit greater genetic turnover rate compared to populations that are well established (Figure 1). For the black-legged tick in southern Quebec, all populations regardless of establishment stage will likely be experiencing regular influxes of new genetic material from the introduction of new individuals. However, the relative amount of novel genetic material relative to that already present locally will differ depending on the establishment stage (Figure 1). For populations still undergoing recolonization-extinction cycles, the relative amounts of novel genetic material will likely be much greater compared to local genetic material due to high local mortality rates (Figure 1). In this case, we would expect to observe great amounts of genetic turnover over time, assuming that introduced individuals originated from multiple random source populations. Conversely, populations that are well established with a self-sustaining pool of local individuals would likely have enough local genetic material to mask the signal of any introduced material (Figure 1). Therefore,

Genetic drift is often found in populations living on the islands because of the habitat isolation, the process of natural selection, interspecific and intraspecific competitions. Therefore, the species on the island always face the the limitation of food source, living space and predation issues, that’s why their population size is forced to decrease and sometimes extinct.

Microsatellite and mitochondria DNA (mtDNA) genetic markers are often used in population genetic studies. Please detail the differences in their mode of inheritance, as well as what types of genetic information that these markers may provide.

In the case of ring species, natural selection and sexual selection each play a role in the divergence of ring species. Selective pressures allowed one phenotype to survive better than others in a certain area; sexual selection could cause divergence because organisms choose mates based on phenotypes. In the case of salamanders, natural selection affected divergence because organisms with certain coloration survived better in coastal or inland environments. In warblers, sexual selection and natural selection seem to play a part in the divergence of the ring species, as forest density and migration distance is variable and affects survival of the species. Molecular and morphological evidence can be used to support multiple species by showing

For isolated black bear populations, heterozygosity is below 0.50 (Boersen et Al. 2003). While in areas of large continuous habitat with ample genetic exchange heterozygosity is around 0.8 (Paetkau and Strobeck 1998). Specifically in their study, through monitoring of the bear locations there was a great deal of gene flow between the two areas due to observations of several male black bears using a forest habitat corridor (Drewry, Van Manen and Ruth 2013). A similar study conducted in Canada concludes in a grizzly bear population the populations were genetically connected via the migration of males from populations. The females did not use habitat corridors as frequently as males, but the movement of individuals was the main way to promote genetic connectivity (Proctor et

When a species gives rise to a new species the small group breaks away and becomes geographically/reproductively isolated from its ancestral group. As long as it remains small and detached, the founder group can experience fairly rapid genetic changes.

There is another side to the biodiversity of the evolutionary field, as the population weakens the species start the inbreeding of smaller populations, thus playing a role in the extinction of a species. Inbreeding is reproduction among members of a species that are genetically similar. The genetic inbreeding is designed to bolster populations of species whose numbers are in decline. However, when only a few species or varieties of a species are cultivated or survive, the genetic diversity of the organism declines, and population is more vulnerable to being wiped out by new diseases or climate changes because of the inbreeding (Alters, 2000).

Gene flow is the process by which individuals (full genotype), and/or the genetic material they carry (certain alleles of genes), move from one population to another and is an important source of genetic variation, because it brings new alleles in the population. Gene flow can be subdivided in three categories: (1) Migration: the movement of full genotypes (individuals) from one population to another within the same species, which may be further integrated later by breeding, (2) Introgression: the movement of genes from one species or strain to another through a process of successful mating (hybridization) and backcrossing, (3) Horizontal (or lateral) gene transfer: the movement of genes from one species or strain to another without successful

Moreover, the migration of individuals from one genetically distinct population to another is also an important way for alleles to be added to or subtracted from a local population. Whenever an organism leaves one population and enters another, it subtracts its genetic information from the population it left and adds it to the population it joins. If it contains rare alleles, it may significantly affect the allele frequency of both populations. The extent of migration need not be great. However, as long as alleles are entering