Biology Chapter 22

An adaptation is _____.

a trait that gives an organism a reproductive advantage in the current environment

Charles Darwin _____.

proposed natural selection as the mechanism of evolution

From his observations of organisms in the Galapagos islands, Darwin reasoned that _____.

organisms had adapted to new environments, giving rise to new species

Which of the following observations led to Darwin’s major inferences?

Members of a population vary in their heritable traits. Although organisms can produce huge numbers of offspring, many of these offspring do not survive.

Which one of the following researchers developed a theory of evolution that was very similar to Charles Darwin’s?

Wallace

A group of small fish live in a lake with a uniformly light-brown sandy bottom. Most of the fish are light brown, but about 10% are mottled. This fish species is often prey for large birds that live on the shore. A construction company dumps a load of gravel in the bottom of the lake, giving it a mottled appearance. Which of these statements presents the most accurate prediction of what will happen to this fish population?

The proportion of mottled fish will increase over time.

Which of the following is an example of the pattern of evolution? (Overview)

the fossil record of the evolution of modern cetaceans

Varieties of Staphylococcus aureus that are resistant to the drug methicillin _____.

-already existed in the population before methicillin was developed -were strongly selected for as methicillin became widely used to treat bacterial infections

A challenge to traditional (pre-1860) ideas about species came from embryology, when it was discovered that _____.

embryos of dissimilar organisms, such as sharks and humans, resemble each other

The theory of evolution through natural selection is considered a scientific theory because _____.

-it is broad enough in scope to explain many observations -it is supported by a massive body of evidence from many disciplines -it is general enough to provide many testable hypotheses

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

Poorly adapted individuals never produce offspring.

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

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 infections were caused by MRSA. How can this result best be explained?

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

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?

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

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

humans and chimpanzees share a relatively recent common ancestor.

What is the meaning of Darwin’s expression "descent with modification"?

Descent with modification refers to evolutionary change over time.

In 1959, doctors began using the powerful antibiotic methicillin to treat infections of Staphylococcus aureus, but within two years, methicillin-resistant strains of S. aureus (MRSA) appeared. How did the resistant strains of S. aureus emerge?

Staphylococcus aureus bacteria that were able to synthesize cell walls using a protein that was not affected by methicillin survived the methicillin treatments and reproduced at higher rates than did other individuals. Over time, these resistant individuals became increasingly common.

What happened in the soapberry bug population in central Florida when the bugs began to feed on smaller goldenrain tree fruits?

Bugs with shorter beaks had more access to food, allowing them to produce more offspring.

Identify the pair of homologous structures.

Maple leaf and oak leaf