Bio Exam 4 Module

adaptations can be thought of as features that increase an organisms' ability to survive and reproduce in a given environment .Which of the following factors can be considered adaptations?

- avoiding predators - attracting mates - metabolic efficiency

What process was responsible for the increase in the relative abundance of black peppered moths from 2% to 95% of the population in London during the industrial revolution?

natural selection

which of the following statements best defines artificial selection?

process of human directed breeding aimed to produce selective traits in selected species

Imagine two species that are thought to have a recent common ancestor. If this idea is correct, these two species most likely have ______.

several phenotypic similarities

Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer or more than this have reduced fitness. Which of the following terms best describes this situation?

stabilizing selection

Given a population that contains genetic variation, what is the correct sequence of the following events under the influence of natural selection?

1. A change occurs in the environment. 2. Poorly adapted individuals have decreased survivorship. 3. Well-adapted individuals leave more offspring than do poorly adapted individuals. 4. Genetic frequencies within the population change.

Artificial selection (breeding) was a very important factor in the development of Darwin's ideas on natural selection. In which of the following respects is artificial selection distinct from natural selection?

Artificial selection does not rely exclusively on the environment to determine relative survival and reproduction rates.

There are many categories of evidence that support evolution by natural selection. Which type of evidence would have been unfamiliar to Darwin during his life?

DNA and genetics

You discover fish living in a cave with no natural light. The fish have no eyes, but they do have eye sockets. Using a Darwinian thought process, which of the following would be the reason for this?

Originally, all fish in the population had eyes and could see. However, in the dark, there was no longer selection for sight, and eyes were eventually lost due to random mutations.

Using the Galápagos finches example, which of the following best explains the Darwinian reason why the insect-eating finch has such a long, narrow beak?

Variation existed in the finch population. Those that naturally had longer, narrower beaks could reach their food more easily, allowing finches with these features to survive and reproduce more often than those that did not.

The cow Bos primigenius (which is bred for meat and milk) has a smaller brain and larger eyes than closely related wild species of ungulates. These traits most likely arose by ________.

artificial selection, because changes in these traits co-occurred with human selection for high milk output and high muscle content

Currently the only predators of Galápagos marine iguanas are Galápagos hawks. Iguana body size is not correlated with risk of hawk predation, although small iguanas can sprint faster than large iguanas. If predators (for example, cats) that preferably catch and eat slower iguanas are introduced to the island, iguana body size is likely to ________ in the absence of other factors; the iguanas would then be under ________ selection.

decrease; directional

Cotton-topped tamarins are small primates with tufts of long white hair on their heads. While studying these creatures, you notice that males with longer hair get more opportunities to mate and father more offspring. To test the hypothesis that having longer hair is adaptive in these males, you should ________.

determine if hair length is heritable

Three-spined stickleback fish (Gasterosteus aculeatus) show substantial heritable variation in gill-raker length related to differences in their diets. Longer gill rakers appear to function better for capturing open-water prey, while shorter gill rakers function better for capturing shallow-water prey. Which of the following types of selection is most likely to be found in a large lake (open water in the middle and shallow water around the sides) with a high density of these fish?

disruptive selection

individual organisms evolve

false

which of the following statements describe the effect evolution on a population?

increasingly better match between a population and its environment

What are adaptations?

inherited characteristics of organisms that enhance their survival

under which of the following conditions could evolution by natural selection not occur?

no genetic variation in a population

Which of Darwin's ideas had the strongest connection to his reading of Malthus's essay on human population growth?

struggle for existence

A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these explanations best explains what happened?

triazine-resistant weeds were more likely to survive and reproduce