21. Evolution

Which of the following is an observation or inference on which natural selection is based? (A) Individuals do not vary in their heritable characteristics. (B) Only well-adapted individuals produce offspring. (C) Species produce more offspring than the environment can support. (D) Nearly all of each individual's offspring will survive and reproduce.

Which of the following is not an observation or inference on which natural selection is based? a. There is heritable variation among individuals. b. Poorly adapted individuals never produce offspring. c. Species produce more offspring than the environment can support. d. Only a fraction of an individual's offspring may survive.

True or false? Some traits are considered vestigial because they existed long ago.

What types of drugs have helped reduce the death rate due to tuberculosis infection, and why have they become less effective more recently?

What are three ways monosaccharides differ from one another?

Which of the following observations helped Darwin shape his concept of descent with modification? a. Species diversity declines farther from the equator. b. Fewer species live on islands than on the nearest continents. c. Birds live on islands located farther from the mainland than the birds' maximum nonstop flight distance. d. South American temperate plants are more similar to the tropical plants of South America than to the temperate plants of Europe.

What type of bond is formed between two sugars in a disaccharide? a. glycosidic linkage b. phosphodiester bond c. peptide bond d. hydrogen bond

Which of the following observations is not part of the theory of natural selection? a. Populations of organisms have more offspring than will survive; b. There is variation among individuals in a population; c. Modern organisms are unrelated; d. Traits can be passed on from parent to offspring; e. Some variants in a population have a higher proba­bility of survival and reproduction than other variants do.

Within six months of effectively using methicillin to treat S. aureus infections in a community, all new S. aureus infections were caused by MRSA. How can this best be explained? a. A patient must have become infected with MRSA from another community. b. In response to the drug, S. aureus began making drug- resistant versions of the protein targeted by the drug. c. Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency. d. S. aureus evolved to resist vaccines.

Traits that are derived from a common ancestor, like the bones of human arms and bird wings, are said to be               .

What holds cellulose molecules together in bundles large enough to form fibers? a. the cell wall b. peptide bonds c. hydrogen bonds d. hydrophobic interactions

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? a. Forelimb evolution was adaptive in people and bats, but not in whales. b. Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy. c. Genes mutate faster in whales than in humans or bats. d. Whales are not properly classified as mammals.

How can evolutionary fitness be measured? Select True or False for each statement. T/F Document how long individuals survive. T/F Count the number of healthy, fertile offspring produced. T/F Determine which individuals are strongest. T/F Determine which phenotype is the most common.

What are the primary functions of carbohydrates in cells? a. cell identity, energy storage, raw material source for synthesis, and structure b. catalysis, energy storage, metabolism, and structure c. catalysis, digestion, energy storage, and information storage d. energy storage, information storage, polymerization, and raw material source for synthesis

Which of the differences listed here could be found among molecules of the same monosaccharide? Select True or False for each statement. T/F There is a difference in the orientation of a hydroxyl group in the ring form. T/F There is a difference in the number of carbons. T/F There is a difference in the position of the carbonyl group in the linear form. T/F There is a difference in the overall shape of the molecule—one is a ring and the other is linear.

The best definition of evolutionary fitness is                  . a. physical health; b. the ability to attract members of the opposite sex; c. the ability to adapt to the environment; d. survival and reproduction relative to other members of the population e. overall strength

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 a. humans and chimpanzees share a relatively recent common ancestor. b. humans evolved from chimpanzees. c. chimpanzees evolved from humans. d. convergent evolution led to the DNA similarities.

According to data presented in this chapter, which of the following are correct? Select True or False for each statement. T/F When individuals change in response to challenges from the environment, their altered traits are passed on to offspring. T/F Species are created independently of each other and do not change over time. T/F Populations—not individuals—change when natural selection occurs. T/F The traits of populations become more perfect over time.

Explain the logic behind the claim that the nuclear envelope is a synapomorphy that defines eukaryotes as a monophyletic group.

An adaptation is a trait of an organism that increases                  . a. its fitness; b. its ability to survive and replicate; c. in frequency in a population over many generations; d. A and B are correct; e. A, B, and C are correct

Some biologists summarize evolution by natural selection with the phrase 'mutation proposes, selection disposes.' Mutation is a process that creates heritable variation. Explain what the phrase means.

Although cellulose and starch are identical in terms of stored chemical energy, our ability to harvest the energy from these two polysaccharides differs considerably. What is responsible for this difference?

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from the air-breathing organ (a simple lung) of an ancestral fish is an example of a. exaptation. b. changes in Hox gene expression. c. paedomorphosis. d. adaptive radiation.

Why don't the biggest and strongest individuals in a population always produce the most offspring? a. The biggest and strongest individuals always have higher fitness. b. In some environments, being big and strong lowers fitness. c. Sometimes the biggest and strongest individuals may choose to have fewer offspring. d. Sometimes the number of offspring is not related to fitness.

If you were given a solution that has a pH of 8.5, what would be its concentration of protons? What is the difference in proton concentration between this solution and one that has a pH of 7?

Contrast the structure of glycogen and chitin in terms of their monosaccharides, glycosidic linkages, and interactions between polysaccharide chains.

Consider the reaction between carbon dioxide and water to form carbonic acid: CO2(g)+H2O(l)⇌CH2O3(aq) In the ocean, carbonic acid immediately dissociates to form a proton and bicarbonate ion, as follows: CH2O3(aq)+H+(aq)⇌CHO3−(aq) If an underwater volcano bubbled additional CO2 into the ocean, would this sequence of reactions be driven to the left or the right? How would this affect the pH of the ocean?

Since the modern synthesis, the technical definition of evolution is a change in                  in a                  over the course of generations. a. traits, species; b, allele frequency, population; c. natural selection, natural environment; d. adaptations, single organism; e. fitness, population

Lysozyme, an enzyme found in human saliva, tears, and other secretions, catalyzes the hydrolysis of the ββ-1,4-glycosidic linkages in peptidoglycan. Predict the effect of this enzyme on bacteria and how it may be involved in human health.

Evaluate this statement: Evolution is said to occur when new traits accumulate over time, increasing complexity.

Galactosemia is a potentially fatal disease that occurs in humans who lack the enzyme that converts galactose to glucose. If you were a physician treating a person with this disease, which of the following would you have them exclude from their diet? a. maltose b. starch c. mannose d. lactose

Similarity in skin color among different human populations appears to be primarily the result of                  . a. natural selection; b. convergent evolution; c. which biological race they belong to; d. A and B are correct; e. A, B, and C are correct

When H2 and CO2 react, acetic acid can be formed spontaneously while the production of formaldehyde requires an input of energy. Which of these conclusions can be drawn from this observation? a. More heat is released when formaldehyde is produced compared to the production of acetic acid. b.Compared to the reactants that it is formed from, formaldehyde has more potential energy than does acetic acid. c. Entropy decreases when acetic acid is produced and increases when formaldehyde is produced. d. Only acetic acid could be produced under conditions that existed in early Earth.

Which of the following taxonomic levels contains organisms that share the most recent common ancestor? a. family; b. order; c. phylum; d. genus; e. class

The geneticist James Crow wrote that successful scientific theories have the following characteristics: (1) They explain otherwise puzzling observations; (2) they provide connections between otherwise disparate observations; (3) they make predictions that can be tested; and (4) they are heuristic, meaning that they open up new avenues of theory and experimentation. Crow added two other elements of scientific theories that he considered important on a personal, emotional level: (5) They should be elegant, in the sense of being simple and powerful; and (6) they should have an element of surprise. How well does the theory of evolution by natural selection fulfill these six criteria?

From what you have learned about water, why do coastal regions tend to have milder climates with cooler summers and warmer winters than do inland areas at the same latitude?

Most mice living on the mainland of Florida are brown, but the mice that live on the sand dunes of the barrier islands have white fur. The differences in color are heritable, determined by genes such as MC1R. It is intuitive that the light color of beach-dwelling mice is an adaptation for blending into their environment—and thus evading predators. What is an evolutionary adaptation? a. a trait that improves the fitness of its bearer, compared with individuals without the trait b. a trait that changes in response to environmental influences within the individual's lifetime c. the ability of an individual to adjust to its environment d. a trait that an individual wants so that it can survive

Over half of the world’s human population lives in cities. Are species adapting to life in these novel urban environments? A global team of researchers (including Tiffany Longo, Jesse Bragger, and Summer Shaheed, shown in in the photo) used white clover as a study system to find out. They measured the production of a compound called hydrogen cyanide (HCN) in rural and urban clover plants. Production of HCN deters herbivores and increases tolerance to drought but has a cost: Clover must expend energy to produce HCN.

Compare how evolution by inheritance of acquired characters and the theory of evolution by natural selection would explain the observation that HCN production is often high in rural environments with many herbivores and low in urban environments with few herbivores.

Over half of the world’s human population lives in cities. Are species adapting to life in these novel urban environments? A global team of researchers (including Tiffany Longo, Jesse Bragger, and Summer Shaheed, shown in in the photo) used white clover as a study system to find out. They measured the production of a compound called hydrogen cyanide (HCN) in rural and urban clover plants. Production of HCN deters herbivores and increases tolerance to drought but has a cost: Clover must expend energy to produce HCN.

The production of HCN is a heritable Mendelian trait controlled by just two unlinked genes (Ch. 14, Section 14.2; clover plants with at least one dominant allele produce HCN, but plants that are homozygous recessive for both genes produce no HCN). Apply Darwin’s four postulates to explain natural selection for low HCN production in a population of clover living in a city with few herbivores and ample water.

Over half of the world’s human population lives in cities. Are species adapting to life in these novel urban environments? A global team of researchers (including Tiffany Longo, Jesse Bragger, and Summer Shaheed, shown in in the photo) used white clover as a study system to find out. They measured the production of a compound called hydrogen cyanide (HCN) in rural and urban clover plants. Production of HCN deters herbivores and increases tolerance to drought but has a cost: Clover must expend energy to produce HCN.

This study was conducted by a network of 287 scientists who sampled 110,019 white clover plants (Trifolium repens) in 160 cities globally. Why do you think they chose to study white clover instead of other plants like red maples, coconut palms, or redwoods? What’s one advantage and one disadvantage of conducting such a large collaboration?

Over half of the world’s human population lives in cities. Are species adapting to life in these novel urban environments? A global team of researchers (including Tiffany Longo, Jesse Bragger, and Summer Shaheed, shown in in the photo) used white clover as a study system to find out. They measured the production of a compound called hydrogen cyanide (HCN) in rural and urban clover plants. Production of HCN deters herbivores and increases tolerance to drought but has a cost: Clover must expend energy to produce HCN.

The researchers measured the frequency of clover plants producing HCN along a transect from each city center out to its rural environment. The graph shows one example of results from Münster, Germany: Anna Bucharova and Christian Lampei sampled 765 plants in 40 populations along a 9.87 km transect. What does the data reveal? What was the prediction of the null hypothesis?

Over half of the world’s human population lives in cities. Are species adapting to life in these novel urban environments? A global team of researchers (including Tiffany Longo, Jesse Bragger, and Summer Shaheed, shown in in the photo) used white clover as a study system to find out. They measured the production of a compound called hydrogen cyanide (HCN) in rural and urban clover plants. Production of HCN deters herbivores and increases tolerance to drought but has a cost: Clover must expend energy to produce HCN.

When a statistical test was used to compare the trend in the data to the prediction of the null hypothesis, the 𝑃 value (see BioSkills 3) was <0.001 for Münster, Germany. Does this result increase or decrease your confidence in the result? Explain.

The global “One Health” movement fosters collaborations at the intersection of human health, veterinary health, and environmental health. Explain why “One Health” seeks to reduce the use of antibiotics in farm animals to improve human health.

Which organism will have the highest fitness?

Which statement would be supported by the concept of common descent?

What is one reason population thinking is so important in biology?

Dog breeds are defined by denoting breed standards, a list of agreed-upon traits that individuals of that breed should possess (such as size, coat, coloring, temperament, etc.). Dog shows rank dogs based on their adherence to these breed standards. Based on this information, which statement about dog breeds below is correct?

True or False: if false, choose the answer that best corrects the statement.

In tree thinking, species are organized from low complexity to high complexity.

The Latin term Scala Naturae reflects which argument?

Based on the following simplified tree, which of the following is more closely related to the pear?

Based on the simplified tree below, identify which node represents the most recent common ancestor between pears and cucumbers.

Which of the following statements is FALSE based on the simplified phylogenetic tree shown?

Explain the relationship between natural selection and evolution.