Descent with Modification: A Darwinian View of Life

How did Hutton's and Lyell's ideas influence Darwin's thinking about evolution?

Scientific hypotheses must be testable (see Concept 1.3). Applying this criterion, are Cuvier's explanation of the fossil record and Lamarck's hypothesis of evolution scientific? Explain your answer in each case.

How does the concept of descent with modification explain both the unity and diversity of life?

If you discovered a fossil of an extinct mammal that lived high in the Andes, would you predict that it would more closely resemble present-day mammals from South American jungles or present-day mammals that live high in Asian mountains? Explain.

Review the relationship between genotype and phenotype (see Figures 14.5 and 14.6). Suppose that in a particular pea population, flowers with the white phenotype are favoured by natural selection. Predict what would happen over time to the frequency of the p allele in the population, and explain your reasoning.

Identify the following elements of hypothesis-based science in this

example: (a) question, (b) hypothesis, (c) prediction, (d) control group, and (e) experimental group.

Explain how the types of data the researchers chose to collect enabled them to test their prediction.

What conclusion do you draw from the data presented above?

Predict what would happen if, after 22 months, guppies from the transplanted population were returned to the source pool. Describe an experiment to test your prediction.

How does evolution account for (a) the similar mammalian forelimbs with different functions shown in Figure 22.15 and (b) the similar forms of the two distantly related mammals shown in Figure 22.18?

Explain how the following statement is inaccurate: "Antibiotics have created drug resistance in MRSA."

WHAT IF? Fossils show that dinosaurs originated 200–250 million years ago. Would you expect the geographic distribution of early dinosaur fossils to be broad (on many continents) or narrow (on one or a few continents only)? Explain.

Which of the following is not an observation or inference on which natural selection is based? 

(A) There is heritable variation among individuals. 

(B) Poorly adapted individuals never produce offspring. 

(C) Species produce more offspring than the environment can support.  

(D) Only a fraction of an individual's offspring may survive.

Which of the following observations helped Darwin shape his concept of descent with modification? 

(A) Species diversity declines farther from the equator. 

(B) Fewer species live on islands than on the nearest continents. 

(C) Birds live on islands located farther from the mainland than the birds' maximum nonstop flight distance. 

(D) South American temperate plants are more similar to the tropical plants of South America than to the temperate plants of Europe.

Within six months of effectively using methicillin to treat S. aureus infections in a community, all new S. aureus infections were caused by MRSA. How can this best be explained? 

(A) A patient must have become infected with MRSA from another community. 

(B) In response to the drug, S. aureus began making drug-resistant versions of the protein targeted by the drug. 

(C) Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency. 

(D) S. aureus evolved to resist vaccines.

The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data? 

(A) Forelimb evolution was adaptive in people and bats, but not in whales.

(B) Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy. 

(C) Genes mutate faster in whales than in humans or bats. 

(D) Whales are not properly classified as mammals.

DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that 

(A) humans and chimpanzees share a relatively recent common ancestor. 

(B) humans evolved from chimpanzees.

(C) chimpanzees evolved from humans. 

(D) convergent evolution led to the DNA similarities.

Explain why anatomical and molecular features often fit a similar nested pattern. In addition, describe a process that can cause this not to be the case.

Mosquitoes resistant to the pesticide DDT first appeared in India in 1959, but now are found throughout the world.

(a) Graph the data in the table below. 

(b) Examine the graph, then hypothesize why the percentage of mosquitoes resistant to DDT rose rapidly. 

(c) Suggest an explanation for the global spread of DDT resistance.

Write a short essay (about 100–150 words) evaluating whether changes to an organism’s physical environment are likely to result in evolutionary change. Use an example to support your reasoning.

This honeypot ant (genus Myrmecocystus) can store liquid food inside its expandable abdomen. Consider other ants you are familiar with, and explain how a honeypot ant exemplifies three key features of life: adaptation, unity, and diversity.