In a certain population of finches, a single gene controls beak length. There are two possible alleles: S, which leads to a short beak, and L, which leads to a long beak. Individuals with the genotype SS will have a short beak, individuals with the genotype LL will have a long beak, and individuals with the genotype SL will have a medium-length beak. Scientists measure that in this population of 1,128 total birds, 321 birds have short beaks, 562 have medium-length beaks, and 245 have long beaks.

Question

In a certain population of finches, a single gene controls beak length. There are two possible alleles: S, which leads to a short beak, and L, which leads to a long beak. Individuals with the genotype SS will have a short beak, individuals with the genotype LL will have a long beak, and individuals with the genotype SL will have a medium-length beak. Scientists measure that in this population of 1,128 total birds, 321 birds have short beaks, 562 have medium-length beaks, and 245 have long beaks.

Ten years later, the measurements are repeated. This time, there were 1,346 birds in the population. 452 have short beaks, 699 have medium-length beaks, and 195 have long beaks.

Use the passage to answer the question.
Based on the data collected 10 years later, this population of finches currently evolving how do you know
A. Yes, because more individuals in the population exhibit the SS genotype than would be expected if the population was in hardy-weinberg equilibrium
B. No because the number of individual that exhibit the SL genotype matches what would be expected if the population was in hardy-weinberg equilibrium
C. No, because fewer individuals in the population exhibit the SS genotype than would be expected if the population was in hardy-weinberg equilibrium
D. Yes, because more individuals in the population exhibit the LL genotype than would be expected if the population was in hardy-weinberg equilibrium

Answer 1

The correct answer is C. No, because fewer individuals in the population exhibit the SS genotype than would be expected if the population was in Hardy-Weinberg equilibrium.

In Hardy-Weinberg equilibrium, the frequencies of different alleles in a population remain constant over time, assuming no evolutionary forces are acting on the population. According to the passage, there are 452 individuals with short beaks in the population, but based on the Hardy-Weinberg equilibrium, we would expect the number of individuals with the SS genotype (short beak) to be higher, given that the allele frequency for S allele can be determined using the formula: p = √(number of SS individuals + 1/2 * number of SL individuals) / total population. Therefore, the fact that there are fewer individuals with the SS genotype than expected indicates that the population is currently evolving.