Bio 2000 History of Evolution MasteringBiology

Which one of the following researchers developed a theory of evolution that was very similar to Charles Darwin's? See Concept 22.2

Wallace Wallace sent Darwin a manuscript outlining a theory of natural selection that was very similar to Darwin's.

A challenge to traditional (pre-1860) ideas about species came from embryology, when it was discovered that _____. See Concept 22.3

embryos of dissimilar organisms, such as sharks and humans, resemble each other Early in development, the similarities among all vertebrate embryos are more apparent than the differences.

The wing of a bat is homologous to the _____ of a whale.

flipper The bones of a bat wing and a whale flipper are homologous.

After his journey on the HMS Beagle, Darwin made this now-famous sketch in his notebook. Which ideas does it represent?

All species are connected to one another in a "family tree." All species are linked to one another by common ancestry. Species descend from other species just as naturally as children come from parents. Darwin's simple drawing shows his thinking: any species can give rise to new species with different features. This is what Darwin described as "descent with modification."

Darwin and Wallace made independent observations in different parts of the world. Which statements are true?

Both observed slightly different species on nearby islands and concluded that species could change over time. Both collected huge numbers of specimens and realized that individuals vary within species. Both witnessed nature up close and realized it was a battlefield with massive casualties. Darwin and Wallace observed similar fact patterns in nature and came to the same explanation about the origin of species.

Which term describes the ability of a trait to be passed on to offspring?

Heritability Heritability is the ability of a trait to be passed on to offspring.

Which of the following statements is an accurate combination of postulates 1 and 2 of natural selection?

Heritable variation exists for traits among individuals in a population.

Which pair of chickens should a farmer breed to produce larger chickens?

Large hen, large rooster Large parents should be bred to produce larger offspring.

What did Wallace conclude from observing that the bones in manatee flippers look similar to the bones in a human arm and hand?

Manatees' arm and finger bones are evidence that manatees share a common ancestor with land mammals For Wallace, the unnecessary arm and finger bones in manatee flippers show that they descended from an ancestor with arms. These vestigial structures are evidence that every species is a modified form of an older species.

When Charles Darwin set sail on the HMS Beagle, what did he and most of his contemporary scientists think about the origin of species?

Most scientists, including Darwin, thought each species was specially created by God in its present form and did not change over time. Special creation was the prevailing idea of the time. Darwin, like most other scientists, began his journey believing species were unchanging and specially created by God.

Which of the following statements about natural selection is true?

Natural selection favors individuals that reproduce more than others. Individuals who are better able to survive and reproduce are more likely to be selected for than individuals who don't survive or cannot reproduce.

Does the ability of a Mycobacterium tuberculosis cell to infect a new host depend on its drug-resistant phenotype?

No, drug-susceptible cells and drug-resistant cells are equally likely to infect a new host. A cell's drug susceptibility or resistance does not affect its ability to infect another host, although a cell's drug resistance would increase that cell's chances to spread in an environment containing antibiotics due to increased survival.

biogeography

Similarity of endemic island species to nearby mainland species The high concentration of marsupial species in Australia

Which observations led Darwin to establish a relationship between extinct and living animals?

The bony shells of armadillos resembled the shells of ancient Glyptodon fossils. The fossilized remains of giant sloths were found in places where smaller sloths now live. Darwin puzzled over why he found fossils of extinct animals in places where he found similar, living animals. Eventually, these observations supported his idea that today's species descend from older, extinct species.

In the United States today, about half of the corn crop is genetically engineered with a protein that is toxic to corn borers, an insect pest of corn. Which of the following conditions would be necessary for evolution of resistance to the toxic protein to occur in the corn borer?

The corn borer must have or generate (by mutation) heritable variation in resistance to the toxic protein. The resistant corn borers must survive better or reproduce more than nonresistant corn borers. If all these conditions are true, then the corn borer might evolve resistance to the toxic protein.

Which of the following statements describes the evolution by natural selection of Mycobacterium tuberculosis bacteria in their new environment?

The drug-resistance trait is an adaptation to the environment in which human hosts are medicated with the antibiotic rifampin. Bacterial cells have higher fitness when they are drug resistant in the new environment in which people have been medicated with antibiotics.

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 statements explains why the pigweed reappeared?

Triazine-resistant weeds were more likely to survive and reproduce.

True or false? It would be difficult to assess whether the drug-susceptible or drug-resistant phenotype in a population of Mycobacterium tuberculosis was more fit in an environment without antibiotics.

True In an environment without antibiotics, individual cells probably would not differ in their reproductive rates or their survival. Without the application of the drug (antibiotic), it would be very difficult to analyze any differences—one wouldn't even be able to sort the cells!

Which of the following is an example of the pattern of evolution? (Overview) See Concept 22.3

the fossil record of the evolution of modern cetaceans The fossil record contains observable data regarding both the morphological development and biogeographical distribution of early cetaceans.

A farmer wishes to develop a strain of high-yield corn that is also resistant to drought. He has the following individuals from the current year's crop: Individual A—Yield: 179 bushels/acre; drought resistance: high Individual B—Yield: 220 bushels/acre; drought resistance: low Individual C—Yield: 185 bushels/acre; drought resistance: medium Individual D—Yield: 140 bushels/acre; drought resistance: high Individual E—Yield: 200 bushels/acre; drought resistance: medium Which of the following crosses would produce the highest corn yield with the highest resistance to drought?

A and E This cross would result in an average corn yield of 189.5 bushels/acre and have a medium-high drought resistance, which is the best you can get for both traits.

Which of the following organisms could be produced by artificial selection?

A cow that produces a large quantity of milk. A cow's ability to produce milk is a heritable trait that can be manipulated by artificial selection.

Which term describes a trait that increases an individual's ability to survive in a particular environment?

Adaptation An adaptation is a trait that increases an individual's ability to survive in a particular environment.

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

Descent with modification refers to evolutionary change over time. Darwin used this term to describe change in organisms over time, or evolutionary change.

direct observation of evolutionary change

Development of drug resistance in bacteria

fossil record

Discovery of transitional forms of horses Discovery of shells of extinct species

For which one of the following observations were both Lamarck's hypothesis and Darwin's hypothesis in complete agreement?

Gradual evolutionary change explains why organisms are well-suited to their environments.

Some monkey flowers (Mimulus guttatus) living near the sites of copper mines can grow in soil containing high concentrations of copper, which is toxic to most plants. Copper tolerance is a heritable trait. The map below shows the area near an old copper mine, which contaminated the nearby soil with copper. A stream flows past the mine toward the lake at the bottom right of the map.

If you were to test monkey flowers growing on the shore of the lake, you would expect nearly 100% of them to be copper tolerant. The population that existed before mining must have included both copper-tolerant and copper-intolerant plants. Nearly 100% of monkey flowers growing in copper-contaminated soil are copper tolerant. Copper tolerance in monkey flowers is an example of a direct observation of evolution. Natural selection favors the survival and reproduction of copper-tolerant plants in copper-contaminated soils. Therefore, the allele for copper tolerance must have been present in some plants when the soil became contaminated. Because copper tolerance provides no benefit to plants in uncontaminated soils, the trait is not as common in plant populations growing outside the contaminated area.

Which of the following statements is an accurate combination of postulates 3 and 4 of natural selection?

Individuals experience differential success in their ability to survive or reproduce due to differences in certain traits. Variation in fitness is required for selection to change the characteristics of a population over time. Remember that selection also requires that the variation in fitness be related to a heritable trait.

The theory of evolution through natural selection is considered a scientific theory because _____. See Concept 22.3

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 All of these answers relate to the definition of a scientific theory.

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

Poorly adapted individuals never produce offspring.

homology

Same genetic code in fireflies and tobacco plants Vestigial pelvis in right whales Similarities in mammalian forelimbs

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. Evolutionary change comes about as the proportion of individuals in the population displaying a particular trait increases from generation to generation.

Identify the four postulates of natural selection.

Survival and reproductive success are variable among individuals in a population. Individuals with certain traits are more likely to survive and reproduce Some trait differences are heritable. Individuals in a population vary in the traits they possess. Darwin's four postulates can be summarized as follows: Individuals in a population vary in the traits they possess. Some trait differences are heritable. Survival and reproductive success are variable among individuals in a population. Individuals with certain traits are more likely to survive and reproduce.

Which of the following observations led to Darwin's major inferences? See Concept 22.2

The first and fourth answers are correct. Members of a population vary in their heritable traits. Although organisms can produce huge numbers of offspring, many of these offspring do not survive. Both are important observations that led to Darwin's major inferences.

Darwin and Wallace independently arrived at the same conclusion that species change over time. Which observations supported their conclusions?

The fossilized remains of giant sloths were similar to the smaller, living sloths Darwin encountered. Mockingbirds from different Galapagos islands had subtle, consistent differences. Tortoises from different Galapagos islands have distinct shells. Birdwing butterflies were found throughout the Malay archipelago, but species differed slightly from island to island. Bird families clustered geographically: cockatoos in the Malay Archipelago and Australia, macaws and hummingbirds in the Americas. The bony shells of armadillos resembled fossilized shells from the extinct Glyptodon. The resemblance between species and the variations among distant species led both Darwin and Wallace to conclude that species change over time.

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? See Concept 22.2

The proportion of mottled fish will increase over time. The mottled fish will tend to escape predation because they are camouflaged against the mottled lake bottom. The mottled fish will most likely produce more offspring.

Varieties of Staphylococcus aureus that are resistant to the drug methicillin _____. See Concept 22.3

The second and fourth answers are correct. already existed in the population before methicillin was developed were strongly selected for as methicillin became widely used to treat bacterial infections Resistant varieties existed in the population but did not confer any advantage until the environment changed with the introduction of the drug methicillin.

As Wallace traveled the Malay Archipelago, he noticed that western islands had placental mammals, like monkeys. Eastern islands had marsupial mammals, like kangaroos. How did Wallace explain this distribution?

The western islands were once connected to Asia and the eastern islands had been connected to Australia. The islands had never been connected to each other. Different kinds of animals were restricted to different regions because species come from pre-existing, nearby species. Because the western islands were once all connected, they would have the same species, which are also found in the mainland in Asia. The eastern islands were once also all connects and had the same species, which are also found in Australia.

From his observations of organisms in the Galapagos islands, Darwin reasoned that _____. See Concept 22.2

organisms had adapted to new environments, giving rise to new species Darwin reasoned that natural selection had increased the match between the organisms and their environment