What is "selected" during natural selection? Explain your answer.
a. Populations with a lot of individuals are selected, in the sense that they produce the most offspring.
b. Individuals with certain advantageous traits are selected, in the sense that they produce the most offspring.
c. Advantageous traits are selected, in the sense that they become more common in the population over time.
d. Species with the most variable genome are selected, in the sense that some of their individuals will definitely stay alive, if a dramatic change in their environment occurs.

Natural selection can cause a change in allele frequencies over time, making the best alleles, those better adapted, more common in the population over generations.

This is called Fitness, and it refers to how many offspring organisms of a particular genotype or phenotype leave in the next generation, relative to others in the group.

Natural selection can act on different alleles of a single gene, or on polygenic traits.

Natural selection can shift phenotype distributions in three ways:

-Stabilizing selection: Intermediate phenotypes are more fit than

extreme ones, e.g. camouflage.

-Directional selection: One extreme phenotype is more fit than all the

others, e.g. are more hidden in shadow and survive better than other

types.

-Disruptive selection: Both extreme phenotypes are more fit than those

in the middle, e.g. mimesis on octopuses.

I hope it helps!