How can harmful alleles persist in a population despite natural selection?
What will be an ideal response?
ANSWER: The diploid condition reduces the effectiveness of natural selection in eliminating harmful
recessive alleles from a population. Although such alleles are disadvantageous in the
homozygous state, they may have little or no effect on heterozygotes. Thus, recessive
alleles can be protected from natural selection by the phenotypic expression of the
dominant allele.
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A. Female preference for swords may have predated the origin of the feature itself. B. Evolution of swords later led to evolution of female preference for swords. C. The same gene that causes sword development also causes development of neural circuits for female preference. D. Adjacent genes on the same chromosome cause sword development and development of neural circuits for female preference. Clarify question: What is the key concept addressed by the question? What type of thinking is required? Gather Content: What do you already know about the evolutionary origins of a characteristic involved in sexual selection? What other information is related to the question? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?