Biology Chapter 22 Review

Questions and Answers

Darwin and Wallace's theory of evolution by natural selection was revolutionary because it ______.

dismissed the idea that species are constant and emphasized the importance of variation and change in populations

The Linnaeus classification system grouped organisms by ______.

increasingly more complex categories

Fossils found in strata reveal that ______.

older strata carry fossils that differ greatly from living organisms

Prior to the work of Lyell and Darwin, the prevailing belief was that Earth is ______.

a few thousand years old, and populations are unchanging Signup and view all the answers

Which of the following statements best explains why modification or change in an organ or tissue during the lifetime of an individual is not inherited?

Characteristics acquired during an organism's life are generally not passed on through genes Signup and view all the answers

When Cuvier considered the fossils found in the vicinity of Paris, he concluded that the extinction of species ______.

occurs, but that there is no evolution Signup and view all the answers

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 Signup and view all the answers

If x indicates the location of fossils of two closely related species, then fossils of their most-recent common ancestor are most likely to occur in which stratum?

C Signup and view all the answers

If x indicates the fossils of two closely related species, neither of which is extinct, then their remains may be found in how many of these strata?

two strata Signup and view all the answers

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 Signup and view all the answers

Starting from the wild mustard Brassica oleracea, breeders have created the strains known as Brussels sprouts, broccoli, kale, and cabbage. Therefore, which of the following statements is correct?

In this wild mustard, there is enough heritable variation to permit these different varieties Signup and view all the answers

What are adaptations?

inherited characteristics of organisms that enhance their survival Signup and view all the answers

Which of these conditions are always true of populations evolving due to natural selection? Condition 1: The population must vary in traits that are heritable. Condition 2: Some heritable traits must increase reproductive success. Condition 3: Individuals pass on most traits that they acquire during their lifetime.

Conditions 1 and 2 Signup and view all the answers

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 Signup and view all the answers

Which one of the following statements best defines artificial selection?

Process of human directed breeding aimed to produce selective traits in selected species Signup and view all the answers

Which statement illustrates the connection between natural selection and overreproduction of a population?

Individuals with inherited traits that promote survival tend to have more surviving offspring Signup and view all the answers

Darwin used the phrase 'descent with modification' to explain ______.

evolution of the unity and diversity of life Signup and view all the answers

Which of the following statements describe evolution?

Natural selection chooses the most popular trait. Signup and view all the answers

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

increasingly better match between a population and its environment Signup and view all the answers

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

struggle for existence Signup and view all the answers

Currently, two extant elephant species (X and Y) are classified in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which statement should be true?

Species X and Y share a greater number of homologies with each other than either does with species Z Signup and view all the answers

Scientific theories ______.

are supported by, and make sense of, many observations Signup and view all the answers

DDT was once considered a 'silver bullet' that would permanently eradicate insect pests. Instead, DDT is largely useless against many insects. Which of these would have prevented this evolution of DDT resistance in insect pests?

None of the insect pests would have genetic variations that resulted in DDT resistance Signup and view all the answers

Of the following anatomical structures, which is homologous to the bones in the wing of a bird?

bones in the flipper of a whale Signup and view all the answers

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, which develop from similar embryonic tissues. These structural similarities are an example of ______.

homology Signup and view all the answers

What must be true of any organ described as vestigial?

It must be homologous to some feature in an ancestor Signup and view all the answers

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that ______.

island forms are descended from mainland forms Signup and view all the answers

Given what we know about evolutionary biology, we expect to find the largest number of endemic species in which of the following geological features, which have existed for at least a few million years?

an isolated ocean island in the tropics Signup and view all the answers

The greatest number of endemic species is expected in environments that are ______.

isolated and show little ecological diversity Signup and view all the answers

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

Poorly adapted individuals never produce offspring Signup and view all the answers

Which of the following observations helped Darwin shape his concept of descent with modification?

South American temperate plants are more similar to the tropical plants of South America than to the temperate plants of Europe Signup and view all the answers

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?

Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy Signup and view all the answers

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 ______.

humans and chimpanzees share a relatively recent common ancestor Signup and view all the answers

Study Notes

Theory of Evolution

Darwin and Wallace revolutionized evolution by natural selection, rejecting the notion of species constancy.
Emphasis on variation and change within populations is central to their theory.

Classification Systems

Linnaeus' classification system organizes organisms into increasingly complex categories.

Fossils and Strata

Fossils in older strata differ considerably from contemporary organisms.
Fossil records support the idea of extinction, though Cuvier argued against evolution.

Earth’s Age and Species Change

Prior to Lyell and Darwin, it was believed that Earth was thousands of years old with stable populations.
Characteristics acquired in a lifetime are not inherited through genes.

Evolutionary Change

Lamarck and Darwin both agreed on gradual evolutionary change enhancing organism-environment suitability.
Fossils of closely related species are found in specific strata, hinting at common ancestry.

Artificial and Natural Selection

Traits like a smaller brain in domesticated cows arise from artificial selection, guided by human preferences.
Breeding from wild mustard illustrates heritable variation resulting in diverse cultivated strains.

Adaptations

Adaptations enhance survival and are heritable traits.

Conditions for Natural Selection

For evolution via natural selection, populations must have heritable traits that influence reproductive success; acquired traits do not count.

Resistance and Survival

The resurgence of triazine-resistant pigweed exemplifies natural selection favoring survivors with advantageous traits.

Definitions

Artificial selection: Human-directed breeding for specific traits.
Natural selection links overpopulation to survival of offspring with inherited advantages.

Malthus and Darwin

Darwin’s concept of “struggle for existence” arose from reading Malthus on population dynamics.
Evolution improves organism-environment compatibility.

Species Classification

Elephants: Species in the same genus have more similarities than those in different genera.

Scientific Theories

Scientific theories are based on observations and provide comprehensive explanations.

DDT Resistance

DDT resistance evolved when genetic variation for resistance existed within insect populations.

Homologous Structures

Whale flipper bones are homologous to bird wing bones, illustrating common ancestry.
Structural similarities among different species highlight the concept of homology.

Vestigial Structures

Vestigial organs must correlate with features from ancestors, retaining a link to evolutionary history.

Island Organisms

Island species' differences from mainland forms indicate descent from ancestral populations.

Endemic Species

Isolated ocean islands, especially in tropical regions, are expected to host numerous endemic species.

Environmental Influences

Environments that are isolated with little ecological diversity promote high endemic species counts.

Observations of Natural Selection

Natural selection operates under the notion that poorly adapted individuals may still reproduce.

Descent with Modification

Similarity among South American temperate and tropical plants supports the idea of descent with modification.

Divergence from Common Ancestors

Unique skeletal structures among humans, bats, and whales suggest adaptation via natural selection in different environments.
Genetic similarities between humans and chimpanzees indicate a recent common ancestor.

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Prepare for your Biology Chapter 22 exam with this review of key concepts. Covering Darwin and Wallace's theory of evolution and the Linnaeus classification system, these flashcards will help solidify your understanding of evolutionary biology and fossil evidence. Test your knowledge and get ready to excel in your studies!