Chapter 22

A population of zooplankton is exposed to a small number of predatory fish that feed on the larger-sized (adult) zooplankton. Which of the following predictions would most likely occur based on the principles of natural selection? ANSWER Adult zooplankton will start to reach sexual maturity when they are still relatively small. The predatory fish will evolve smaller mouths so that they do not drive their prey to extinction. The zooplankton will become sexually mature at larger sizes. The predatory fish will evolve poor eyesight so as to preserve their food supply. The first and the third listed responses are both good predictions.

Adult zooplankton will start to reach sexual maturity when they are still relatively small.

During periods of rapid environmental change, what may happen to a species that was well-suited to the former environment? ANSWER All of the listed responses are correct. The species may go extinct. Individuals with particular traits that provide an advantage in the new environment will have higher reproductive success. The population may change so much in adapting to the new environment that it is considered a new species. Traits that were favorable in the original environment may be detrimental in the new environment.

All of the listed responses are correct.

Which of the following is correct regarding natural selection? ANSWER All of the listed responses are correct. Natural selection is a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than do individuals without those traits. Over time, natural selection can increase the correspondence between organisms and their environments. If an environment changes, or if individuals move to a new environment, natural selection may result in adaptation to these new conditions, sometimes giving rise to new species. Individuals do not evolve; populations do. None of the listed responses is correct.

All of the listed responses are correct.

Which of the following people developed the idea known as the scala naturae, or scale of nature? ANSWER Aristotle Darwin Wallace Hutton Lyell Linnaeus

Aristotle

The modern idea of extinction as a common occurrence in Earth's history was first proposed in the early 19th century writings of __________. ANSWER Cuvier Lamarck Aristotle Wallace Lyell

Cuvier

How did Hutton and Lyell's ideas influence Charles Darwin's thinking? ANSWER Darwin reasoned that the Earth must be very old and that slow, subtle processes could produce substantial biological changes. Darwin reasoned that the Earth must be very young and that sudden events could produce substantial biological changes. Darwin reasoned that organisms could pass acquired modifications to their offspring. Darwin used Hutton and Lyell's ideas to develop the scala naturae. Darwin speculated that extinctions are common events during the course of time. None of the listed responses is correct.

Darwin reasoned that the Earth must be very old and that slow, subtle processes could produce substantial biological changes.

An important challenge to traditional (pre-1860) ideas about species was the observation that seemingly dissimilar organisms such as hummingbirds, humans, and whales have similar skeletal structures. This most directly suggested to biologists that __________. dissimilar organisms might have evolved from a distant, common ancestor only the best-adapted organisms can survive advantageous changes can be passed along to offspring most evolution occurs rapidly following a mass extinction All of the listed responses are correct.

Dissimilar organisms might have evolved from a distant, common ancestor.

What does it mean to describe evolution as a scientific theory? ANSWER Evolution is a broad model that is supported by many observations and much experimental evidence. Evolution is narrow in scope and focuses only on very specific examples. Evolution does not explain how organisms have changed over time. Evolution is not testable. Evolution is not observable.

Evolution is a broad model that is supported by many observations and much experimental evidence

How does our understanding of genetics today refute Lamarck's principle of the inheritance of acquired characteristics? ANSWER Experiments in genetics show that traits acquired during an individual's lifetime are not inherited in the way proposed by Lamarck. Experiments in genetics show that traits acquired during an individual's lifetime are inherited in the way proposed by Lamarck. Parts of the body that are not used will deteriorate over time. Parts of the body that are used extensively will become stronger and be passed to offspring. All organisms are perfect and permanent. All of the listed responses are correct.

Experiments in genetics show that traits acquired during an individual's lifetime are not inherited in the way proposed by Lamarck.

Paleontology, the study of fossils, was developed by __________. ANSWER Georges Cuvier James Hutton Charles Lyell Charles Darwin Aristotle

Georges Cuvier

Which of the following is not an observation or inference that Darwin made while developing his theory of evolution? ANSWER Interactions between individuals and their environments cause individuals to evolve. Members of a population often vary in their inherited traits. Individuals whose inherited traits give them a higher probability of surviving and reproducing in a given environment tend to leave more offspring than do other individuals. All species can produce more offspring than their environments can support, and many of these offspring fail to survive and reproduce. The unequal abilities of individuals to survive and reproduce will lead to the accumulation of favorable traits in the population over generations.

Interactions between individuals and their environments cause individuals to evolve.

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? ANSWER Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy. Humans and bats evolved by natural selection, and whales evolved by Lamarckian mechanisms. Forelimb evolution was adaptive in people and bats, but not in whales. Genes mutate faster in whales than in humans or bats. Whales are not properly classified as mammals.

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

What insight did Darwin gain from reading Thomas Malthus's essay on human suffering? ANSWER Organisms have the capacity to overreproduce. Natural selection should be capable of considerable modifications over hundreds of thousands of generations. Population size usually remains relatively stable. Favorable characteristics of a population accumulate over time. All of the listed responses are correct.

Organisms have the capacity to overreproduce.

Which of the following is not an observation or inference on which natural selection is based? ANSWER Poorly adapted individuals never produce offspring. There is heritable variation among individuals. Species produce more offspring than the environment can support. Individuals whose characteristics are best suited to the environment generally leave more offspring than those whose characteristics are less well suited. Only a fraction of an individual's offspring may survive.

Poorly adapted individuals never produce offspring

The bacteria Staphylococcus aureus has developed resistance to some antibiotic drugs. How did this resistance come about? ANSWER Some members of the bacteria populations possessed some sort of genetic variation for antibiotic resistance that was selected for when the bacteria was exposed to the drugs. Some members of the bacteria populations mutated and developed resistance. Some members of the bacteria populations acquired resistance genes by being exposed to the antibiotic. Genetic recombination of alleles during sexual reproduction in the bacteria produced antibiotic resistant genes. Some members of the bacteria populations possessed some sort of genetic variation for antibiotic resistance that was selected against when the bacteria was exposed to the drugs.

Some members of the bacteria populations possessed some sort of genetic variation for antibiotic resistance that was selected for when the bacteria was exposed to the drugs.

What does each branch point on an evolutionary tree represent? ANSWER The common ancestor of the lineages beginning there and to the right of it A homologous characteristic shared by all groups to the right of the branch point An analogous characteristic shared by all groups to the right of the branch point A homologous characteristic shared by all groups to the left of the branch point Convergent evolution

The common ancestor of the lineages beginning there and to the right of it

All known organisms transcribe genetic information to protein molecules via the same genetic code. This finding strongly supports the hypothesis that __________. ANSWER all organisms are descended from a single common ancestor there's only one possible way to encode information in a macromolecule the earliest macromolecules probably arose when lightning struck an oxygen-free atmosphere the genetic code will never be broken None of the listed responses is correct.

all organisms are descended from a single common ancestor

The breeding of plants and animals for particular traits by humans is called __________. ANSWER artificial selection natural selection sexual recombination paleontology homology

artificial selection

Even though rodents known as sugar gliders and flying squirrels are members of distinctly different groups of organisms and live on different continents, they possess similar characteristics. This is an example of __________. ANSWER convergent evolution homology adaptation acquired characteristics use and disuse All of the listed responses are correct.

convergent evolution

Darwin originally defined evolution as __________. ANSWER descent with modification the passing of acquired characteristics to offspring an individual's ability to adapt to its environment a way to classify organisms based on morphological similarities None of the listed responses is correct.

descent with modification

Organisms found only in specific places in the world are referred to as __________. ANSWER endemic analogous homologous introduced species tetrapods convergent

endemic

Animals that possess homologous structures probably __________. ANSWER evolved from the same ancestor are headed for extinction have increased genetic diversity by chance had similar mutations independently in the past are not related

evolved from the same ancestor

At the time Darwin voyaged on the HMS Beagle, the popularly accepted theory in Western culture that explained the origin of Earth's plants and animals held that the various species __________. ANSWER had been created by divine intervention a few thousand years before arose continually from nonliving materials by spontaneous generation had evolved from now-extinct organisms arose from a single species that had survived the biblical flood are all related to one another

had been created by divine intervention a few thousand years before

On an evolutionary tree, __________. ANSWER homologous characteristics form a nested pattern organisms that are positioned close to each other are closely related scientists are sure of the correct placement and relationships of all organisms the concept of descent with modification is not well-represented None of the listed responses is correct.

homologous characteristics form a nested pattern

Adaptations are defined as __________. ANSWER inherited characteristics of organisms that enhance their survival and reproduction in specific environments inherited characteristics of organisms that reduce their survival and reproduction in specific environments characteristics that are acquired during the lifetime of an organism characteristics that become larger and stronger during the lifetime of an organism characteristics that are not passed to offspring characteristics that seem to have marginal, if any, importance to an organism

inherited characteristics of organisms that enhance their survival and reproduction in specific environments

Darwin's explanation of how adaptations arise centered on __________. ANSWER natural selection inheritance of acquired characteristics use and disuse artificial selection descent with modification

natural selection

In Darwin's view of descent with modification, __________. ANSWER natural selection can improve the match between an organism and its environment an organism's traits only affect its own survival individuals can evolve environmental changes have no effect on the organisms living in that environment natural selection only operates when an organism needs to evolve

natural selection can improve the match between an organism and its environment

A(n) __________ is the smallest unit that can evolve. ANSWER population individual species community adaptation

population

Carolus Linnaeus is considered to be the founder of __________, and he __________. the binomial classification system; thought that resemblances among different species reflected the pattern of their creation paleontology; believed in catastrophism uniformitarianism; believed the same geologic forces are operating today that occurred in the past genetics; described the mechanism for descent with modification evolution; first proposed that acquired characteristics are inherited

the binomial classification system; thought that resemblances among different species reflected the pattern of their creation

Homologies that appear to have marginal, if any, importance to an organism are called __________. ANSWER vestigial structures adaptations homologous structures acquired characteristics mutations None of the listed responses is correct.

vestigial structures