Gene flow is transfer of genes from one population to another. Gene flow is actually the movement of genes between various populations. Examples of this are a bacterium that only lives in a particular lake having bacteria that only lives in other lakes. A well known example of this is E coli. This bacterium will only grow in water containing certain conditions.
Factors affecting gene flow:
1. Mobility: gene flow is lower in species having low mobility or dispersal.
2. Distance: When there is long distances between populations then it results in low gene flow.
3. Population size: Small population size results in low gene flow.
4. Social structure: It is highly affected by social structure because of genetic variation.
5. Endogamous populations: Endogamous population results in low gene flow because they allow only individuals of their group and caste. Therefore, new genetic material is not introduced into the population and thus results in low gene flow.
6. Exogamous population: It allows more genetic diversity and thus more gene flow as they allow individuals outside their group and caste.
7. Reproductively isolated: Reproductively isolated is defined as the inability of species to breed within the related species. Therefore, it allows less gene flow as distant populations results in low genetic difference.
Differential gene flow
Gene flow is a complex process that involves multiple factors. One of these factors is called differential gene flow. Differential gene flow can occur when there is a form of natural selection. Examples of this are when animals interbreed to improve their genetic material.
Another example of gene flow can be caused by geographical isolation. This occurs when two species breed at the same time and do not interbreed for thousands of years. The resulting offspring are usually those of the older species. In order to determine how interbreeding is going to occur, you need to check the mating strategies of both species. This can be done by examining the characteristics of their genitalia.
Another factor that can cause migration is an antigenic shift. When existing species migrates, it will often cause a slight change in its appearance and its immune system. These changes are often compared to the effects of a wildfire.
Gene flow and Migration
Changes in the environment can affect migration. Examples of environmental changes include climate, soil type, and terrain. Other examples include parasites, pathogens, and negative experiences in the hosts’ history. As you can see, any change in the gene pool of a species can lead to rapid change and fluctuations in population sizes.
Natural selection is one of the forces that drive gene flow. It is most commonly associated with sexual reproduction, but it can also occur through other processes. The concept is simple. When a reproductive process is slow or artificially inhibited, it causes natural selection to favor or disadvantage those traits that are slower to reproduce.
Gene flow and genetic drift
Gene flow and drift can sometimes occur together. The concept behind this phenomenon is simple. If there is a major dieoff or bottleneck in a population, some individuals will have to endure high levels of diversity for a time period until the die-off event becomes over. Then these individuals may migrate to a new area, increasing the genetic diversity of the area. This creates the need for adaptation, sometimes leading to evolution of new traits.
Horizontal gene flow
Apart from the above described scenarios, gene flow can also occur through horizontal gene flow. This refers to neighboring loci being passed on between species. For example, humans and chimpanzees share a number of genes common to both these species. If a hominid is separated from its neighbors through evolution, it will be expected to experience some changes in its appearance, thanks to the parallel spread of its genes. Similarly, the migration of bacteria between various species can cause drastic changes, sometimes resulting in completely new species.
Monitor gene flow
The only way to monitor gene flow between two or more populations is to carry out a genetic analysis using polymerase chain reactions (PCRs). Polymerase chain reactions (PCRs) are a method of amplifying DNA without introducing any form of transcriptional restriction, making it possible to track the behavior of populations. In addition, PCR amplifies only those genes that have been changed by selection during the generation of the sample. These changes are then detected with the help of sequence alignment through sequence motifs. When combined with knowledge testing, an integrated whole genome context, such as that derived from an ancestry database, can also be used to assess the extent of gene flow between populations.
What is Gene Flow when it comes to speciation is a much more complicated question. Speciation refers to the process of identifying specific genetic differences among species. Some of the methods used to identify speciation include genetic markers such as sequences of pairs of chromosomes, hybridization between closely related strains, and the occurrence of new mutations (i.e., abnormalities in the genetic code that are not normal).
The primary cause of speciation is the movement of species between environments, but sometimes, biological mechanisms causing gene flow are a bit slower and less direct than that of changes in the environment. For instance, after a long period of evolution, an organism may undergo a metamorphosis that results in the development of a new physical form, which would be very similar to an ancestor of the current organism. During this process, a part of the DNA of the former ancestor is inserted into the genome of the recipient organism. However, although the origin of this insertional event is often difficult to pinpoint, the process of adding segments of DNA to an organism’s genome is known as speciation.
There are many examples of how the rate of speciation has evolved over the history of life on earth. Speciation is often referred to as the gradual accumulation or replacement of different sets of genes in a species over time. In all these cases, the rate of evolution is changing as each specie undergoes a metamorphosis. One example of a slowly evolving species is the split between the hippo and the lion lived only about 200 million years ago. The gap in their reproductive capacity caused the gap in their appearance, and speciation resulted in the two species being present on earth.