Answer:
- Interruption in the genetic flow between separated groups
- The emergence of new mutations in each of the groups, and their accumulation in time. Slow and gradual differentiation between populations.
- Genetic divergence by natural selection and reproductive isolation
- Prezigotic isolation mechanisms
Explanation:
Allopatric speciation consists of the geographic separation of a continuous genetic background that can give place to two or more new geographically isolated populations. These separations might be due to migration, extinction of geographically intermediate populations, or geological events. In this speciation, some barriers impede genetic interchange, or genetic flux, as the two new groups that are separated can not get together and mate anymore. These barriers might be geographical or ecological.
The process of allopatric speciation involves different steps that affect organisms:
- The emergence of the barrier.
- Interruption in the genetic interchange
- The occurrence of new mutations and their accumulation in time in each population. Slow and gradual differentiation.
- Genetic divergence by natural selection and reproductive isolation makes it impossible for the two groups to mate even if the barrier disappears.
- Prezigotic isolation mechanisms will be favored by selection if occurs a secondary contact between the new species in formation.
The body needs to maintain the amount of oxygen that reaches our cells. If we exercise a lot, our breathing rate increases. More oxygen enables our cells to <span>more quickly respire aerobically, so that our muscles can contract more rapidly.
</span>
Answer:
The answer to the given question is C.
Explanation:
Natural selection:
The population contains both superior as well as inferior organisms where natural resources are limiting so it will cause competition between organisms. As a result of competition, it will select superiors, and inferiors are deleted and they are given reproductive advantages. Due to this reproductive advantage new population emerges. It is more suitable for the environment.
Natural selection divides into three parts that are directional, disruptive, and stabilizing selection.
This is an example of natural selection. Environmental conditions create pressure on the individuals and if they can survive and become fittest, their number increases in the population. This is according to Darwin's theory in the struggle for existence. These organisms survived as the fittest organisms to match climatic conditions.
Stabilizing selection: This operates when features coincide with the optimal environmental conditions and the organisms survive in a population. Stabilizing selection pressures do not promote evolutionary change but tend to maintain stability within the population from generation to generation.
In the beginning, directional selection - the organism develops characters to survive in response to gradual changes in the environmental conditions. It works on a range of phenotypes existing within a population and exerts selection pressure which moves the mean phenotype to one phenotypic extreme. When the mean phenotype overlaps with the new optimum environmental conditions, stabilizing selection will take over.
During mitosis, the chromosome copies separate the nucleus divides and the cell divides. This produces identical two cells called daughter cells. The main purpose of mitosis is for growth and to replace worn out cells.
