Question

The following table provides phenotypic data for a population of mammoths living in cold environments based on fossil and DNA evidence.



Based on this data and your knowledge of natural selection, which explanation best explains the trends seen in the data?

(1 point)
Responses

This population of mammoths appear to be in Hardy-Weinberg equilibrium since no allele frequencies are changing over time.
This population of mammoths appear to be in Hardy-Weinberg equilibrium since no allele frequencies are changing over time.

Individuals with thick fur migrated into the population of mammoths, increasing the proportion of these individuals.
Individuals with thick fur migrated into the population of mammoths, increasing the proportion of these individuals.

Individuals within this population of mammoths tend to only mate with individuals that have thick fur.
Individuals within this population of mammoths tend to only mate with individuals that have thick fur.

Individuals

Answer 1

Individuals with thick fur had higher survival and reproductive success (directional natural selection), so alleles for thick fur increased in frequency.

Reason: the cold environment favors thick fur, causing a consistent change in allele frequencies over time. This is not Hardy–Weinberg equilibrium (allele frequencies are changing), and the trend is better explained by selection than by migration or assortative mating alone.