Question

the events that lead to genetic drift are ______.
a. always natural disasters
b. random
c. predictable
d. related to human activities

please select the best answer from the choices provided

a
b
c
d

Explanation:

⚡ Using what you learned: mechanisms of evolution and natural selection

Step 1: Define Genetic Drift

Genetic drift is a mechanism of evolution characterized by random fluctuations in the frequency of gene variants (alleles) in a population. Unlike natural selection, which favors traits that provide an advantage, genetic drift changes allele frequencies purely by chance.

Step 2: Analyze the Options

• a. always natural disasters: While natural disasters can cause genetic drift (known as the bottleneck effect), they are not the only cause. Other non-disaster events, like a small group migrating to a new area (founder effect), also cause genetic drift.
• b. random: Genetic drift is defined by random, chance events that affect which individuals survive, reproduce, or pass on their genes.
• c. predictable: Because genetic drift is driven by chance, the specific changes in allele frequencies are unpredictable.
• d. related to human activities: While human activities can cause population declines that lead to genetic drift, many natural, non-human events also cause it. It is not inherently tied to human activity.

Therefore, the defining characteristic of the events leading to genetic drift is that they are random.

Answer:

B