What will occur if a species is divided into two groups and allowed to reproduce in different environments for many generations?

The original species will diverge into two new species. It will occur speciation. It will occur some sort of allopatric speciation.

Explanation:  

When the original species is divided and placed under different environments, where they can reproduce for many generations, many changes or mutations will occur in each group. These changes will depend on each group´s environment and its ecological pressures and will lead to divergence. Pressures act on individuals and make them adapt to the new environmental conditions. Generation after generation, the genotype of individuals will increase the fitness to survive and reproduce. The fixation of mutations will increase the difference among both groups, up to the diverging point into two new species.

The biological concept of species states that individuals of the same species can reproduce because they have a genetic reservoir in common: many genetic variants.

Genetic variability is the measure of a species organism´s tendency to differentiate. In genetic variability, individuals of the same species are not identical. They are recognizable as members of the same species, but they differ in shape, function, and behavior. There exist variations among individuals of the same species.

Genetic variability originates from mutations, recombinations, and karyotype alterations. It allows or makes possible evolution.

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 flux, as the two new populations 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:

•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 answer is :

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