The gene frequency for a particular trait in a population was determined to be 80% A (dominant allele) and 20% a (recessive allele). Fifty years later, the gene frequency was determined to be 60% A and 40% a. What does this change most likely indicate about the gene pool?

Explanation:

Microevolution is a change in the frequency of gene variants, alleles, in a population, typically occurring over a relatively short time period.

Population genetics is the field of biology that studies allele frequencies in populations and how they change over time.

Allele frequency refers to how common an allele is in a population. It is determined by counting how many times the allele appears in the population then dividing by the total number of copies of the gene.

\text{Frequency of allele }AFrequency of allele Astart text, F, r, e, q, u, e, n, c, y, space, o, f, space, a, l, l, e, l, e, space, end text, A ==equals \dfrac{{\text{Number of copies of allele }A \:{\text {in population{\text{Total number of }{\text{copies of gene in population}}}  

Total number of copies of gene in population

Number of copies of allele Ain population

start fraction, start text, N, u, m, b, e, r, space, o, f, space, c, o, p, i, e, s, space, o, f, space, a, l, l, e, l, e, space, end text, A, start text, i, n, space, p, o, p, u, l, a, t, i, o, n, end text, divided by, start text, T, o, t, a, l, space, n, u, m, b, e, r, space, o, f, space, end text, start text, c, o, p, i, e, s, space, o, f, space, g, e, n, e, space, i, n, space, p, o, p, u, l, a, t, i, o, n, end text, end fraction

The gene pool of a population consists of all the copies of all the genes in that population.

It has remained stable.

It is evolving through natural selection.

It has become predominantly recessive.

It is affected by climate change.

Explanation:

it has to be A

more words for this could be abiotic and biotic

abiotic: living organisms within an ecosystem

biotic: non-living organisms within an ecosystem