Among a population of lizards inhabiting an arid habitat, the skin color is controlled by two alleles-B (brown skin color) that is dominant over b (green skin color). The green lizards comprise only 4 percent of the population whereas the brown lizards comprise the rest. Over a long period of time, increased rainfall in the area leads to transformation of the habitat, with growth of shrubs and small trees. The brown and green lizard numbers almost reverse with the green lizards approaching 81 percent of the total population. Calculate the allele frequency for the green skin color before and after the climate change occurred. Why did the brown lizard, which initially had greater relative fitness than the green lizard, reduce in number drastically?

Question

Among a population of lizards inhabiting an arid habitat, the skin color is controlled by two alleles-B (brown skin color) that is dominant over b (green skin color). The green lizards comprise only 4 percent of the population whereas the brown lizards comprise the rest. Over a long period of time, increased rainfall in the area leads to transformation of the habitat, with growth of shrubs and small trees. The brown and green lizard numbers almost reverse with the green lizards approaching 81 percent of the total population. Calculate the allele frequency for the green skin color before and after the climate change occurred. Why did the brown lizard, which initially had greater relative fitness than the green lizard, reduce in number drastically?

(1 point)

2, 9, because relative fitness is dependent on environmental conditions

0.2, 0.9; because relative fitness is dependent on environmental conditions

0.2, 0.9 because the green lizard population acquired new adaptations that caused them to increase in number

0.4, 0.81; because the green lizard population acquired new adaptations that caused them to increase in number

Answer 1

The correct answer is 0.2, 0.9; because relative fitness is dependent on environmental conditions.

Before the climate change occurred, the green lizard allele frequency can be calculated as follows:
- Total population = 100%
- Percentage of green lizards = 4%
- Frequency of green allele (b) = √(4/100) = 0.2

After the climate change occurred, the green lizard allele frequency can be calculated as follows:
- Percentage of green lizards = 81%
- Frequency of green allele (b) = √(81/100) = 0.9

The drastic reduction in brown lizard numbers is due to the fact that the green lizards had a higher relative fitness in the new environment with shrubs and small trees. The green skin color likely provided them with better camouflage, allowing them to avoid predators more effectively and increase their survival and reproductive success. Over time, this led to an increase in the frequency of the green allele and a decrease in the frequency of the brown allele in the population.