Exam 13: How Populations Evolve

Which of the following would prevent an organism from becoming part of the fossil record when it dies?

Tay-Sachs is inherited as an autosomal recessive allele. Homozygous individuals die within the first few years of life. However, there is some evidence that heterozygous individuals are more resistant to tuberculosis. Which of the following statements about Tay-Sachs is true?

Darwin found that many of the species on the Galápagos islands

Microevolution, or evolution at its smallest scale, occurs when

Brown-eye genes are dominant over blue-eye genes. What is the best explanation for the fact that all the blue-eye alleles have not disappeared in the human population?

After reading the paragraph below, answer the questions that follow. Desert pupfish live in springs of the American Southwest. Today there are about 30 species of pupfish, but they all evolved from a common Pleistocene ancestor. The southwestern United States was once much wetter than it is now, and the Pleistocene pupfish flourished over a wide geographic area. Over thousands of years, however, the Sierra Nevada mountain range was pushed upward by geological forces, blocking rainfall from the Pacific Ocean. As the large lakes dried up, small groups of pupfish remained in springs and pools fed by groundwater seepage. Now, although many of these small springs still have pupfish, each population, through evolution, has become very different from populations of pupfish in other springs. -Which of the following statements represents a probable explanation for differences among pupfish populations?

During the 1950s, a scientist named Lysenko tried to solve the food shortages in the Soviet Union by breeding wheat that could grow in Siberia. He theorized that if individual wheat plants were exposed to cold, they would develop additional cold tolerance and pass it to their offspring. Based on the ideas of artificial and natural selection, do you think this project worked as planned?

Which of the following will tend to produce adaptive changes in populations?

Which of the following statements would Darwin have disagreed with?

Darwin was the first person to draw an evolutionary tree, a diagram that represents

A population of butterflies has an allele B for big spots on the wings and b for small spots on the wings. The table below provides data about this population. Genotype BB Bb bb Number of butterflies 300 400 300 Genotype frequency 0.3 0.4 0.3 Regarding these data about the butterfly population, which of the following statements is correct?

The recessive allele of a gene causes cystic fibrosis. For this gene among Caucasians, p = 0.98. If a Caucasian population is in Hardy-Weinberg equilibrium with respect to this gene, what proportion of babies is born homozygous recessive and therefore suffers cystic fibrosis?

Which of the following statements regarding natural selection is false?

In populations of the greater prairie chicken in Illinois, genetic diversity was

Humans share several features with salamanders. Certain genes and proteins are nearly identical between the two species; both species have four limbs with a similar skeletal structure; the species' early embryos are very similar; and where the salamander has a functional tail, humans have a vestigial tailbone. In evolutionary terms, these are examples of

A population of 1,000 birds exists on a small Pacific island. Some of the birds are yellow, a characteristic determined by a recessive allele. The others are green, a characteristic determined by a dominant allele. A hurricane on the island kills most of the birds from this population. Only 10 remain, and those birds all have yellow feathers. Which of the following statements is true?

The sickle-cell allele produces a serious blood disease in homozygotes. Why doesn't natural selection eliminate this allele from all human populations?

A news article discussing the evolution of domestic dogs from wolves included this statement: "On its way from pack-hunting carnivore to fireside companion, dogs learned to love-or at least live on-wheat, rice, barley, corn, and potatoes." What is a more scientifically accurate way to state what happened with dogs?

Some butterflies can ingest toxic chemicals from the milkweed plants they feed on and then can store those chemicals in their body. Because toxins stored in the butterflies are toxic to birds, the birds avoid eating the butterflies. Which of the following is the best explanation for this situation?

Genetic differences between populations tend to be reduced by