1. The principle that is not part of Darwin's theory of evolution by natural selection is: Mutations are the ultimate source of genetic variation. To get to this answer, you should be familiar with the key principles of Darwin's theory of evolution by natural selection. One way to study Darwin's theory is by reading his book "On the Origin of Species." In this case, you would notice that Darwin did not propose that mutations are the ultimate source of genetic variation. Rather, he emphasized the role of variation already present in a population, which is acted upon by natural selection.
2. The factor that most consistently requires a small population as a precondition for its occurrence is genetic drift. To arrive at this answer, you should understand the different evolutionary factors (genetic drift, gene flow, mutation, and natural selection) and the conditions under which they are most likely to occur. Genetic drift refers to random changes in gene frequencies that can have a larger impact in small populations due to chance events. This makes genetic drift more influential in small populations compared to larger populations.
3. The best explanation for the fact that a population of penguins in Antarctica cannot fly, even though there is evidence that millions of years ago their ancestors were able to fly, is that ancestral penguins with shorter wings were better swimmers for catching food and evading predators, so they passed the genes for smaller wings on to their descendants. To arrive at this answer, you should be familiar with the concept of natural selection and how it acts on the traits of organisms over time. In this case, the ancestors of penguins with shorter wings had a selective advantage in swimming, which led to the selection of smaller wings and the loss of flight ability in modern-day penguins.
5. The most probable explanation for the change in frequency of phenotypes in the insect population over five years is that the adaptive value of allele b decreased. To determine the explanation, you should carefully analyze the data table and compare the frequencies of the different phenotypes over time. In this case, you would notice that the frequency of the Dark Brown phenotype (genotype BB and Bb) decreased over five years, while the frequency of the Light Brown phenotype (genotype bb) increased. This suggests a decrease in the adaptive value of allele b, leading to a shift in phenotype frequencies.
6. The approximate percentage of heterozygous genotypes in the mouse population is 26%. To calculate this percentage, you should understand the concept of Hardy-Weinberg equilibrium and the equations associated with it. In this case, you can use the equation for calculating the frequency of heterozygotes (2pq), where p is the frequency of the dominant allele and q is the frequency of the recessive allele. Given that the frequency of the recessive allele is 0.15, you can calculate p as 1 - q and then substitute the values into the equation to find the answer.
7. The frequency of the dominant allele (H) in the population of monkeys is 0.57. To find this frequency, you can use the information provided regarding the percentage of monkeys with long hair at the tip of their tails. If 67% of the monkeys have long hair (HH or Hh), then the frequency of the dominant allele (H) can be calculated as the square root of the proportion of long-haired monkeys. Simply take the square root of 0.67 to find the frequency of the dominant allele.