Ch.23 - Evolution by Natural SelectionSee all chapters
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Ch.1 - Introduction to Biology
Ch.2 - Chemistry
Ch.3 - Water
Ch.4 - Carbon
Ch.5 - Biological Molecules
Ch.6 - Cells
Ch.7 - The Membrane
Ch.8 - Energy and Metabolism
Ch.9 - Respiration
Ch.10 - Photosynthesis
Ch.11 - Cell Signaling
Ch.12 - Cell Division
Ch.13 - Meiosis
Ch.14 - Mendelian Genetics
Ch.15 - Chromosomal Theory of Inheritance
Ch.16 - DNA Synthesis
Ch.17 - Gene Expression
Ch.18 - Regulation of Expression
Ch.19 - Viruses
Ch.20 - Biotechnology
Ch.21 - Genomics
Ch.22 - Development
Ch.23 - Evolution by Natural Selection
Ch.24 - Evolution of Populations
Ch.25 - Speciation
Ch.26 - History of Life on Earth
Ch.27 - Phylogeny
Ch.28 - Prokaryotes
Ch.29 - Protists
Ch.30 - Plants
Ch.31 - Fungi
Ch.32 - Overview of Animals
Ch.33 - Invertebrates
Ch.34 - Vertebrates
Ch.35 - Plant Anatomy
Ch.36 - Vascular Plant Transport
Ch.37 - Soil
Ch.38 - Plant Reproduction
Ch.39 - Plant Sensation and Response
Ch.40 - Animal Form and Function
Ch.41 - Digestive System
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Ch.43 - Immune System
Ch.44 - Osmoregulation and Excretion
Ch.45 - Endocrine System
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Ch.51 - Animal Behavior
Ch.52 - Population Ecology
Ch.53 - Community Ecology
Ch.54 - Ecosystems
Ch.55 - Conservation Biology

Descent with Modification

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Sections
Descent with Modification

Concept #1: Descent With Modification

Concept #2: Fitness, Adaptation, and Artificial Selection

Concept #3: Convergent and Divergent Evolution

Concept #4: Vestigial Traits and Evolutionary Misconceptions

Additional Problems
Darwin studied the different species of finches: a. on the Galapagos islands b. in southern South America c. in Great Britain d. in North America e. in the fossil beds
Both kangaroos and grasshoppers have enlarged hind limbs used for jumping. Both evolved independently from short-legged animals. The similarity in leg structure and function is an example of a. homology b. convergence c. intrasexual selection d. intersexual selection e. allopatric speciation
The French taxonomist, who in 1809 was the first scientist to suggest that organisms that use one part of their body repeatedly would increase their abilities, was:  a.  Charles Darwin b.  James Hutton c.  Jean Lamarck d.  Georges Buffon e.  Charles Lyell
The scientist who published "On the Origin of Species by Means of Natural Selection" in 1859 was:  a.  James Hutton b.  Jean Lamarck c.  Georges Buffon d.  Charles Darwin e.  Charles Lyell
Which question can evolution not explain?  a. The diversity of species on Earth b. The common ancestry of all species on Earth c. How life started on Earth d. The same types of molecules are found in all organisms e. The origin of new species
Darwin’s book in which he described his views on evolution is: a. Favoured Races b. Principles of Geology c. On the Principle of Population d. On the Origin of Species e. Survival of the Fittest
An elephant uses its trunk to bring food to its mouth; a human uses their hand to do this. An elephant’s trunk and a human’s hand are _____ structures.a. homologousb. analogousc. convergentd. choices A and Ce. choices B and C
About thirteen different species of finches inhabit the Galapagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the thirteen species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six ground finch species (genus Geospiza). If the six ground finch species have evolved most recently, then which of these is the most logical prediction?a. They should be limited to the six islands that most recently emerged from the sea.b. The chances of hybridization between two ground finch species should be less than the chances of hybridization between two tree finch species.c. Their genomes should be more similar to each other than are the genomes of the five tree finch species.d. They should share fewer anatomical homologies with each other than they share with the tree finches.
Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would shed the most light on whether these structures are homologous or whether they are, instead, the result of convergent evolution?a. The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical.b. Both species are well adapted to their particular environments.c. The sizes of the structures in adult members of both species are similar in size.d. Both species reproduce sexually.e. The two species live at great distance from each other.
A researcher discovered a species of moth that lays its eggs on oak trees. Eggs are laid at two distinct times of the year: early in spring when the oak trees are flowering and in midsummer when flowering is past. Caterpillars from eggs that hatch in spring feed on oak flowers and look like oak flowers. But caterpillars that hatch in summer feed on oak leaves and look like oak twigs.How does the same population of moths produce such different-looking caterpillars on the same trees? To answer this question, the biologist caught many female moths from the same population and collected their eggs. He put at least one egg from each female into eight identical cups. The eggs hatched, and at least two larvae from each female were maintained in one of the four temperature and light conditions listed below.Refer to the accompanying figure below. Recall that eggs from the same female were exposed to each of the eight treatments used. This aspect of the experimental design tested which of the following hypotheses?a. Differences in diet trigger the development of different types of caterpillars.b. The differences are genetic. A female will either produce all flowerlike caterpillars or all twig-like caterpillars.c. The longer day lengths of summer trigger the development of twig-like caterpillars. d. Differences in air pressure, due to elevation, trigger the development of different types of caterpillars.
Which of the five aspects of Darwin’s theory of evolution was one for which Darwin had little or no evidence but that molecular and cellular biology supports. a. Evolution has happened b. All life on earth has a common ancestor c. Gradual evolution d. Descent with modification e. Natural Selection
A researcher discovered a species of moth that lays its eggs on oak trees. Eggs are laid at two distinct times of the year: early in spring when the oak trees are flowering and in midsummer when flowering is past. Caterpillars from eggs that hatch in spring feed on oak flowers and look like oak flowers. But caterpillars that hatch in summer feed on oak leaves and look like oak twigs.How does the same population of moths produce such different-looking caterpillars on the same trees? To answer this question, the biologist caught many female moths from the same population and collected their eggs. He put at least one egg from each female into eight identical cups. The eggs hatched, and at least two larvae from each female were maintained in one of the four temperature and light conditions listed below.Refer to the accompanying figure below. In every case, caterpillars that feed on oak flowers look like oak flowers. In every case, caterpillars that were raised on oak leaves looked like twigs. These results support which of the following hypotheses?a. The differences are genetic. A female will either produce all flowerlike caterpillars or all twig-like caterpillars.b. The longer day lengths of summer trigger the development of twig-like caterpillars.c. Differences in air pressure, due to elevation, trigger the development of different types of caterpillars.d. Differences in diet trigger the development of different types of caterpillars.
Scientists identify genes in sequenced genomes by looking for genes with similar sequences in other genomes. What evolutionary concept allows them to do this?a. Sexual selectionb. Homologyc. Convergenced. Genetic Drifte. Migration
A researcher discovered a species of moth that lays its eggs on oak trees. Eggs are laid at two distinct times of the year: early in spring when the oak trees are flowering and in midsummer when flowering is past. Caterpillars from eggs that hatch in spring feed on oak flowers and look like oak flowers. But caterpillars that hatch in summer feed on oak leaves and look like oak twigs.How does the same population of moths produce such different-looking caterpillars on the same trees? To answer this question, the biologist caught many female moths from the same population and collected their eggs. He put at least one egg from each female into eight identical cups. The eggs hatched, and at least two larvae from each female were maintained in one of the four temperature and light conditions listed below.Refer to the accompanying figure below. Which one of the following is NOT a plausible hypothesis to explain the differences in caterpillar appearance observed in this population?a. The cooler temperatures of spring trigger the development of flower-like caterpillars.b. The longer day lengths of summer trigger the development of twig-like caterpillars.c. Differences in air pressure, due to differences in elevation, trigger the development of different types of caterpillars.d. Differences in diet trigger the development of different types of caterpillars.
Which was not a component of Darwin’s theory of evolution? a. common ancestry of all life b. descent with modification in a branching pattern c. genetic drift d. natural selection e. gradual change over long periods
In Spadefoot toads a change in the environment can change the developmental pathway so that the carnivore morph (form) develops rather than the omnivore morph. Which of the following best describes this process?a. The environment mutates genes leading to a genetically different formb. The environment directly alters developing cells without affecting genes in any wayc. The environment affects the expression of genes involved in development of the tadpoled. The environment results in the evolution of a new speciese. The environment creates new Hox genes
Currently, two extant elephant species (X and Y) are placed in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which statement should be true?a. Species X and Y are not related to species Z.b. Species X, Y and Z share a common ancestor, but nothing more can be claimed than this.c. Species X and Y are the result of artificial selection from an ancestral species Z.d. Species X and Y share a greater number of homologies with each other than either does with species Z. e. Species X and Y share a common ancestor that is still extant (in other words, not yet extinct).
Which of the following is an example of homology?a. The arm of a human and the pectoral fin of a dolphinb. The wing of a bird and the front leg of a lizardc. Hemoglobin as an oxygen carrier in humans and in chimpanzeesd. All of the above 
While examining a skeleton of a snake you notice that it has a pelvic girdle and tiny limb bones like other reptiles. The most likely explanation for the presence of a pelvic girdle and small bones in this snake is:a. This skeleton is a transitional formb. They are a developmental mutationc. They are vestigial structuresd. They are analogous to bird wings
Convergent evolution means:  a.  That organisms living in similar habitats may develop similar traits even though they are not closely related b.  Different organisms will never have similar traits c.  That evolution converges on a desired body form based on an external plan or design d.  That all species will eventually have the same traits e.  That some life forms are more evolved and therefore superior to other life forms
A gradual change from an ancestral type was referred to by Darwin as:  a.  Uniformitarianism b.  Descent with modification c.  Catastrophism d.  Convergent evolution e.  Principle of superposition
According to Darwin, natural selection usually:  a.  Neither preserves nor rejects harmful variations in a population b.  Preserves harmful variations and rejects favorable variations in a population c.  Preserves favorable and harmful variations in a population d.  Preserves favorable variations and rejects harmful variations in a population
The Canary Islands are seven islands just west of the African continent. The islands gradually became colonized with life: plants, lizards, birds, etc) Three different species of lizards found on the islands are similar to one species found on the African continent (Thorpe & Brown, 1989). Because of this, scientists assume that lizards traveled from Africa to the Canary Islands by floating on tree trunks washed out to sea. Lizards eat a variety of insects and plants. Which statement describes the availability of food for lizards on the Canary Islands?a. Finding food is not a problem since food is always in abundant supply.b. Since lizards can eat a variety of foods, there is likely to be enough food for all of the lizards at all times.c. Lizards can get by on very little food, so the food supply does not matter.d. It is likely that sometimes there is enough food, but at other times there is not enough food for all of the lizards.
The relatively short term changes in allele frequencies within a species or population is:  a.  Convergent evolution b.  Artificial selection c.  Microevolution d.  Natural selection e.  The principle of superposition
The Canary Islands are seven islands just west of the African continent. The islands gradually became colonized with life (plants, lizards, birds, etc). Three different species of lizards found on the islands are similar to one species found on the African continent (Thorpe & Brown, 1989). Because of this, scientists assume that lizards traveled from Africa to the Canary Islands by floating on tree trunks washed out to sea.A well-established population of lizards is made up of hundreds of individual lizards. On an island, all lizards in a lizard population are likely to:a. be indistinguishable, since there is a lot of interbreeding in isolated populations.b. be the same on the inside but display differences in their external features.c. be similar, yet have some significant differences in their internal and external features.d. be the same on the outside but display differences in their internal features.
The Canary Islands are seven islands just west of the African continent. The islands gradually became colonized with life (plants, lizards, birds, etc). Three different species of lizards found on the islands are similar to one species found on the African continent (Thorpe & Brown, 1989). Because of this, scientists assume that lizards traveled from Africa to the Canary Islands by floating on tree trunks washed out to sea.Which statement best describes how traits in lizards will be inherited by offspring?a. When parent lizards learn to catch particular insects, their offspring can inherit their specific insect-catching-skills.b. When parent lizards develop stronger claws through repeated use in catching prey, their offspring can inherit their stronger-claw trait.c. When parent lizards' claws are underdeveloped because easy food sources are available, their offspring can inherit their weakened claws.d. When a parent lizard is born with an extra finger on its claws, its offspring can inherit six-fingered claws.
The Canary Islands are seven islands just west of the African continent. The islands gradually became colonized with life (plants, lizards, birds, etc). Three different species of lizards found on the islands are similar to one species found on the African continent (Thorpe & Brown, 1989). Because of this, scientists assume that lizards traveled from Africa to the Canary Islands by floating on tree trunks washed out to sea. According to the theory of natural selection, where did the variations in body size in the three species of lizards most likely come from?a. The lizards needed to change in order to survive, so beneficial new traits developed.b. The lizards wanted to become different in size, so beneficial new traits gradually appeared in the population.c. Random genetic changes and sexual recombination both created new variations.d. The island environment caused genetic changes in the lizards.
After Darwin concluded his voyage on the Beagle, he proposed that the process of natural selection was the mechanism for: a. artificial selection b. evolution c. sexual selection d. speciation e. overpopulation of finches on the Galapagos Islands
Farmers and horticulturalists bred broccoli, cauliflower, kale, and cabbage from the wild mustard plant through _____.  a.  Artificial selection b.  Evolution c.  Genetic drift d.  Natural selection e.  Sexual selection
Which of the following is a term used in conjunction with how the traits of organisms that leave more offspring become more common in succeeding generations? a. natural selection b. artificial selection c. fitness d. reproduction e. creativity
Darwin concluded from his observations of nature and readings that:  a.  Individuals compete with one another for limited resources and only the fittest survive b.  Individuals compete with one another for limited resources and only the fittest reproduce c.  Population growth is unlimited, leading to the large numbers of organisms d.  An individual's chance of survival and reproduction are mostly due to chance and changes in the environment e.  Species do not change over time
Which of the following was NOT a factor that  Darwin considered in formulating his hypothesis of evolution?a. Mutations cause living things to change.b. Nature selects the most fit organisms to survive.c. Better adapted individuals contribute more surviving offspring to a population.d. Organisms increase in number faster then their food supply.e. Variations contributing to evolution must be heritable.
Explain how the hooked ends of the forelimb on the anteater might be an adaptation?
What are the differences between homologous traits and analogous traits?
Many mammals have tails. How is the monkey's tail an adaptation? 
List the four "forces" of evolution. Explain what each one means.
The evolution from water to land came with a major problem; dehydration. Define dehydration. What have vertebrate animals done to cope with this?
Define evolution be sure to include in your definition what actually evolves.Describe the principles of natural selection. 
What did Aristotle/Cuvier think about evolution?
Which of the following were important facts in Charles Darwin's development of theory of evolution by natural selection? Select ALL that apply.A. Much of the variation among individuals within a population is heritable.B. Organisms can inherit characters that were acquired during their parents lifetime.C. No two individuals are exactly the same, rather, every population displays enormous variability.
What is the significance of crossing over (which leads to genetic recombination) to the process of evolution?
The basis of natural selection depends on genetic variation. Please list and explain at least 6 mechanisms for generation if genetic variation within a population.
The amino acids which comprise an enzyme's active site do not change significantly from species to species. Explain why.
What does it mean that natural selection acts on the individual? Or acts on the phenotype?
Darwin was not the first one to propose that living organisms evolve. What Charles Darwin did was to propose a mechanism that explains how evolution occurs, which he called Natural Selection. In less than 200 words, summarize what Natural Selection is.
Describe phenotypic plasticity. How might this influence natural selection pressures on a genetic trait in a population?
In most species males are the most colourful sex, but in humans females are often more admired for their physical beauty than males. Explain using sexual selection theory (Please do not write more ten lines).
The fact that DNA sequences are more similar in more closely related organisms is evidence of ______.A. optimal design in organismsB. adaptationC. mutationD. descent with modification
Contrast neutral theory with selection theory.
Explain the statement "It is the population, not the individual, that evolves." Define the terms population, species, and gene pool.
How is the term Cambrian explosion misleading?Distinguish between convergent evolution and divergent evolution. Which type of selection would you expect to be the major factor in convergent evolution? In divergent evolution? Why are mutations important in evolution? Natural selection can lead to the evolution of prezygotic isolating mechanisms, but not post-zygotic isolating mechanisms? Explain.
What are the three basic factors required for evolution?