Which of the following possible isolating mechanisms prevents individuals from wasting time and energy hybridizing with an individual of another species?  

Which of the following provides an example of a mechanical isolation as a prezygotic barrier?  

Two populations of birds with somewhat different coloration live on opposite sides of a peninsula. The habitat between the populations is not suitable for these birds. When birds from the two populations are brought together in captivity, they interbreed and produce fertile young whose appearance is intermediate between the two parents. In the wild, the two populations remain separate as a result of which of the following factors?  

Studies of Neanderthal DNA revealed that there are more similarities to non-African DNA than reference sequences from West Africans. Additionally, scientists found that Neanderthal DNA is as closely related to East Asians as to Europeans. These patterns indicate that interbreeding occurred before human migration further east. Which evolutionary force most likely generated these results?  

Which following term best describes the following phrase: Species that breed at different times of the day, in different seasons, or different years cannot mix their gametes  

Which of the following statements is accurate with regard to a population in Hardy-Weinberg equilibrium?  

Most Swiss starlings (birds) produce four to five eggs in each clutch. Starlings producing more or less eggs have reduced fitness. Which of the following terms best describes this situation?  

Which of the following statements best describes macroevolution?  

Which of the following conditions is most likely to reinforce isolating mechanisms between two species that occasionally hybridize?  

In a Hardy-Weinberg population with two alleles A1and A2 that are in equilibrium, the frequency of the allele A2 is 0.3. What is the frequency of individuals that are homozygous for this allele?