Chapter 18 Quiz

What is the best definition of adaptation?

A heritable trait or behavior that aids an organism's survival and reproduction

Why is having a way of defining species and distinguishing between them important for the study of evolution?

A distinction between species allows scientists to understand the common origin of all species.

Which statement best describes what happens when an antibiotic is applied to a population of bacteria?

A gene for resistance, already present in the population, increases in frequency.

Which option is the best definition of species?

A group of individual organisms that interbreed and produce viable, fertile offspring

How does the scientific meaning of theory differ from the common vernacular meaning?

A scientific theory is a statement that has been proven correct, while people often use it to mean a statement that has not yet been verified.

Which type of speciation, allopatric or sympatric, is more common? Why?

Allopatric speciation is more common because it prevents gene flow betweenthe species.

What is an example of convergent evolution? How does it support the theory of evolution by natural selection?

An example of convergent evolution is the development of the same function, flying, in organisms that do not share a recent common ancestry, such as insects and birds. The fact that wings that allow flight have developed from very different original structures suggests that the process of natural selection can produce similar adaptations in two very different types of organisms who share a similar environment.

Prior to 1800 in England, the typical moth of the species Biston betularia (peppered moth) had a light pattern. Dark-colored moths were rare. By the late nineteenth century, the light-colored moths were rare, and the moths with dark patterns were abundant.The cause of this change was hypothesized to be selective predation by birds (Tutt, 1896). During the Industrial Revolution, soot and other wastes from industrial processes killed tree lichens and darkened tree trunks. Thus, prior to the pollution of the Industrial Revolution, dark moths stood out on light-colored trees and were vulnerable to predators. With the rise of pollution, however, the coloring of moths vulnerable to predators changed to light. In the late 1900s, England cleaned up its air, and pollution decreased. The bark of trees went from dark to light.Which outcome to the populations of peppered moth would you expect, given this environmental change?

An increase in the number of light moths and a decrease in the number of dark moths

Each of the following observations comes from a different scientific discipline. Which observation best supports Darwin's concept of descent with modification?

Botanists provide evidence that South American temperate plants have more in common with South American tropical plants than temperate plants from Europe.

The selective breeding of plants and animals that possess desired traits is a process called artificial selection. For example, broccoli, cabbage, and kale are all vegetables that have been selected from one species of wild mustard.How is artificial selection both similar to and different from Darwin's conception of natural selection? Does artificial selection provide evidence for evolution by natural selection? Explain.

Both artificial selection and natural selection are the differential reproduction of individual organisms with favored traits. In artificial selection, humans have actively modified plants and animals by selecting and breeding individuals with traits deemed desirable. In natural selection, the most successful individuals in a species are selected by the species to reproduce.

What do both rate of speciation models have in common?

Both models ignore the influence of gene flow for simplicity's sake.

Biogeography is the study of biological species as they relate to geographical spaceand geological time. The fossil record shows that dinosaurs originated about 200 to250 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)? Explain.

Broad because dinosaurs originated before the breakup of Pangaea

Genes important in the embryonic development of animals have been relatively well conserved during evolution. This means they are more similar among different species than many other genes. What explains this genetic conservation across animal species?

Changes in the genes that are important to embryonic development have been relatively minor because mutational tweaking in the embryo has magnified consequences in the adult.

What is least likely to be a factor that increases the probability of speciation by adaptive radiation?

Genetic drift in a population increases.

If a population stopped reproducing sexually, but still reproduced asexually, how would its genetic variation be affected over time? Could speciation occur in this situation?

Genetic variation would decrease, and speciation would be possible.

Which process is divergent evolution?

Groups of organisms evolve in different directions from a common point.

In which situation would hybrid reproduction would two species to continue divergence?

If two closely related species continue to produce hybrids, they will develop reproductive barriers to prevent production of hybrids, to ensure that they remain separate species.

In which situation would hybrid reproduction cause two species to fuse into one?

If two species occupy the same niche in the same area, they can either compete or they can collaborate and reproduce with each other, eventually fusing into a single species.

What is unique about speciation due to adaptive radiation?

It leads to multiple species forming from one parent species.

Paleontologists have recovered a fossil for an organism named Archaeopteryx. It has many features in common with reptiles, but, like birds, shows evidence of feathers.For what aspect of evolutionary theory does this piece of evidence suggest support?

Modern species share a common ancestor.

The term microevolution describes evolution on its smallest scale: the change in allele frequencies in a population over generations. DDT is a pesticide that was widely in use in the United States from the 1940s until 1972. The table summarizes a particular allele frequency in laboratory strains of the common fruit fly, Drosophila melanogaster. Using this information, in which model did natural selection improve the match between D. mealanogaster and its environment through microevolution?

Mutations from the application of DDT caused the allele conferring DDT resistance to appear in the population.

Which scientific concept did Charles Darwin and Alfred Wallace independently discover?

Natural selection

How does an adaptation, such as better running speed, relate to natural selection?

Natural selection produces adaptations, such as better running speed, to help individuals survive and reproduce.

Which component of speciation would be least likely to be a part of punctuated equilibrium?

Ongoing gene flow

What are homologous structures?

Parallel structures in diverse organisms

Which statement is false?

Punctuated equilibrium is most likely to occur in a large population in a stable environment.

In a hybrid zone, in addition to interacting, what else do two closely related species do?

Reproduce

What do scientists focus on to distinguish between species?

Reproductive barriers

Which situation means reinforcement is more likely to occur in the hybrid zone?

Reproductive barriers strengthen.

What is the main difference between an autopolyploid individual and an allopolyploid individual?

Source of extra chromosomes

Given your understanding of evolutionary theory and the relationship between evolution and the genetic makeup of populations, which statement is false?

The degree of relatedness between groups of organisms is only sometimes reflected in the similarity of their DNA sequences.

The process of mutation, which generates genetic variation, is random. Thus, life has evolved, and continues to evolve, randomly. Which statement is an appropriately evidence-based refinement of the above?

The process of mutation, which generates genetic variation, is random. However, the process of natural selection, which results in adaptations like the fit between a flower and its pollinator, favors variants which are better able to survive and reproduce. Natural selection is not random, so the overall process of evolution is not random, either.

Which statement best describes the relationship between the theory of evolution and the origin of life?

The theory does not try to explain the origin of life.

What is an example of an adaptation?

The webbed feet of a duck help it swim.

The upper forelimbs of humans and cats have fairly similar structures. In contrast, the upper forelimbs of whales (their flippers) have bones with a different shape and proportion from both cats and humans. Interestingly, genetic data suggest that all three organisms have a common ancestor from about the same point in time. What is a likely explanation for these data?

The whale flipper is an adaptive characteristic unique to its water environment.

Prior to 1800 in England, the typical moth of the species Biston betularia (peppered moth) had a light pattern. Dark-colored moths were rare. By the late nineteenth century, the light-colored moths were rare, and the moths with dark patterns were abundant.The cause of this change was hypothesized to be selective predation by birds (Tutt, 1896). During the Industrial Revolution, soot and other wastes from industrial processes killed tree lichens and darkened tree trunks. Thus, prior to the pollution of the Industrial Revolution, dark moths stood out on light-colored trees and were vulnerable to predators. With the rise of pollution, however, the coloring of moths vulnerable to predators changed to light.Which aspect of Darwin's theory of evolution does the story of the peppered moth most clearly illustrate?

There is differential reproduction of individuals with favorable traits.

Which situation is an example of a prezygotic barrier?

Two species of insects mate, but the zygote does not survive.

Why do scientists consider vestigial structures evidence for evolution?

Vestigial structures are the result of convergent evolution, so they are good evidence that natural selection act similarly in similar environmental conditions.

Which situation is most likely an example of convergent evolution?

Worms and snakes both move without legs.