Which of the following mechanisms of evolution can act on a single population at the same time?a. only natural selection and genetic drift can happen at the same timeb. genetic drift, migration, and mutation can happen at the same time, but not with natural selectionc. Natural selection, genetic drift, migration and muration can all happen at the same timed. none of the above. only 2 mech. can act on a population at a time

a. only natural selection and genetic drift can happen at the same time

Explanation:

Genetic drift and natural selection are the only evolutionary mechanisms that can occur at the same time in the same population, but this rarely happens.

Natural selection occurs when the organisms least adapted to the characteristics of the environment have disadvantages to survive and end up dying over time, allowing the most adapted organisms to survive and generate descendants who will inherit the same adapted characteristics.

Genetic drift, in turn, refers to a situation where a large number of members of a population have been wiped out due to an environmental catastrophe such as tsunami, earthquake, among others. In this case, a small part of the population survives and must adapt, often generating a new species.

The correct answer is B) genetic drift, migration, and mutation can happen at the same time, but not with natural selection.

Explanation:

Genetic drift, migration, mutation and natural selection are all agents of evolution. They are not mutually exclusive. More importantly, they all depend on natural selection.

Genetic Drift is a phenomenon that is common to biological populations alone. It occurs as an aftereffect of a random selection of alleles which determine the characteristics of the next generation of offspring.

A Genetic deviation can be effected by the surroundings. For example, Brown fur rabbits migrating to the north or south pole may become genetic drift that causes their offspring's fur to have white as a primary colour and eventually become white all around.

Sticking with the above example, we can also introduce natural selection.

Natural selection happens when members of a population with certain genetic markers are more likely to survive and reproduce, and thus transfer on their alleles to the next generation of organisms with other genotypes.

When there is a high probability that an organism with a particular trait/genotypes will survive, reproduce and replicate it's alleles to the next generation, Natural selection is said to be in force.

In the Southpole where it is predominantly white during winter, a white rabbit is more likely to survive than one which is white but has some spots.

The chances are, therefore, that the all-white rabbit will dominate the population in that geographical location with time.

Mutagens are the chief causes of mutation in a species. A Mutation takes place when there is a change or damage to the DNA of a living thing thus resulting in a change in its nature (outwardly or internally).

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