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.
Answer:
Because of using fossil fuels nowadays it is used to air pollute the earth causing global warming.
Explanation:
Answer:The anesthesia has blocked the Inter-neurons from carrying signals to the brain.
This is called 'controlled' or 'prescribed' burning. Usually fires in the environment are regarded as undesirable and dangerous, but fires actually fulfil an important ecological role, and animals and plants had adapted to a certain frequency and intensity of fires. The seeds of some trees or grasses germinate after forest or grass fires, as the more open conditions after a fire allows the seedlings to compete and avoid being shaded and smothered by more established trees. Unfortunately, farming and forestry practices have in many cases resulted in a reduction of fires. A reduction in the frequency of fires also allows the build up of dead wood, and when a wild fire does occur, the amount of available fuel results in very hot, large and damaging fires. Therefore, management of forests and other environments such as prairies often use controlled burns to avoid the buildup of dead organic mass and to replicate the natural fire cycle.
