Answer:
Allele frequencies change randomly each generation is the example of genetic drift.
Answer:
Species separated by a physical barrier for a long time, suffer allopatric speciation, so they can not interbreed anymore.
Explanation:
Allopatric speciation consists of the geographic separation of a continuous genetic background giving 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 flow, as the two new populations that are separated can not get together and mate anymore. These barriers might be geographical or ecological.
Vicariance is the geographical separation of an original population into two or more new groups. Discontinuities in the physical environment like rivers, mountains, water, etc., are physical barriers that impede genetic flow between the separated groups.
The process of allopatric speciation involves different steps:
- 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 favored by selection once occurs a secondary contact between the new species in formation.
The mutated proteins are random changes in the sequence while the normal sequence was meant to be how it is
Three
different ways the relatedness of species could be assessed is through:
<span>1.
</span>Their genotype. Similarity in DNA between the species is a good
indication of their relatedness.
<span>2.
</span>Their phenotype. If the two species have similar body form and function,
then there is a good possibility that they are related.
<span>The presence of intermediates, either living
or in the fossil record, can show relatedness between two species.</span>
