Consider two populations (population A and population B) of the same plant species and the gene Xx. Researchers discover that there is constant flow of the x allele from population B into population A. This allele happens to be detrimental to individuals in population A because of the local soil conditions. In this case gene flow:

Which of the following is one of the four conditions necessary for natural selection to occur in a population? fewer organisms are born than the habitat can support mutation does not occur organisms have identical characteristics variation is inherited

Next pretest: evolution select the correct answer in a laboratory population of flies, the female flies are gray and the males are yellowish gray. biologists observed that all the male flies had an equal chance for reproduction, but the male flies with the brightest colors were more likely to successfully reproduce. what phenomenon could explain such a change? a sexual selection b. disruptive selection c. stabilizing selection d. directional selection

Freckles are a dominant trait in humans. both of the girls have the genotype ff for freckles. if either one marries a man with no freckles, what are the chances that their children will have freckles?