Question

Imagine that alien scientists are carrying out an experiment on Earth. They effectively construct a "shield" surrounding the planet that limits the amount of sunlight/UV radiation that reaches Earth's surface. If the alien scientists return after 60,000 years, what may they discover?
A. Natural selection would likely have selected for humans with little skin pigmentation.
B. Natural selection would have selected for individuals that are predisposed to rickets.
C. Natural selection will not have selected for any particular trait in humans, as natural selection is a process that requires millions of years to occur.
D. Natural selection will have selected for humans with two mutant G6PD alleles.

Answer 1

Answer:

A: Natural selection would likely have selected for humans with little skin pigmentation

Explanation:

Sunlight/UV radiation has been discovered to be an inducer of immediate pigment darkening or melanin production. Hence, if a sunlight/UV radiation shield is is constructed to limit the amount of radiation that reaches the earth, after a while, this might become a selection factor.

Natural selection would likely have selected for humans with little skin pigmentation, those that are able to successfully adapt to the effects of limited sunlight/uv radiation. Humans who are not able to adapt to limited sunlight/uv radiation eventually get replaced in the population by those that are well adapted.

According to theory of natural selection which was proposed by Darwin, organisms with heritable traits that enable them to adapt to changes in an environment will survive more and produce offspring which are also able to survive. This eventually leads to eventual dominance of well adapted organisms in the environment over those that are not able to or weakly adapted.

The correct option is A