2Chapter 15 Evolution Section 1: Darwin’s Theory of Natural Selection Section 2: Evidence of EvolutionSection 3: Shaping Evolutionary Theory
3Darwin on the HMS Beagle Chapter 15Evolution15.1 Darwin’s Theory of Natural SelectionDarwin on the HMS BeagleDarwin’s role on the ship was as naturalist and companion to the captain.His job was to collect biological and geological specimens during the ship’s travel.
4Chapter 15Evolution15.1 Darwin’s Theory of Natural SelectionThe Galápagos IslandsDarwin began to collect mockingbirds, finches, and other animals on the four islands.He noticed that the different islands seemed to have their own, slightly different varieties of animals.
5Populations from the mainland changed after reaching the Galápagos. Chapter 15Evolution15.1 Darwin’s Theory of Natural SelectionAlmost every specimen that Darwin had collected on the islands was new to European scientists.Populations from the mainland changed after reaching the Galápagos.
6Darwin Continued His Studies Chapter 15Evolution15.1 Darwin’s Theory of Natural SelectionDarwin Continued His StudiesDarwin hypothesized that new species could appear gradually through small changes in ancestral species.Darwin inferred that if humans could change species by artificial selection, then perhaps the same process could work in nature.
7Individuals in a population show variations. Chapter 15Evolution15.1 Darwin’s Theory of Natural SelectionNatural SelectionIndividuals in a population show variations.Variations can be inherited.Organisms have more offspring than can survive on available resources.Variations that increase reproductive success will have a greater chance of being passed on.Visualizing Natural Selection
9Darwin’s theory of natural selection is not synonymous with evolution. Chapter 15Evolution15.1 Darwin’s Theory of Natural SelectionThe Origin of SpeciesDarwin published On the Origin of Species by Means of Natural Selection in 1859.Darwin’s theory of natural selection is not synonymous with evolution.It is a means of explaining how evolution works.
1015.2 Evidence of Evolution Support for Evolution The fossil record Chapter 15Evolution15.2 Evidence of EvolutionSupport for EvolutionThe fossil recordFossils provide a record of species that lived long ago.Fossils show that ancient species share similarities with species that now live on Earth.GlyptodontArmadillo
11Chapter 15Evolution15.2 Evidence of EvolutionDerived traits are newly evolved features, such as feathers, that do not appear in the fossils of common ancestors.Ancestral traits are more primitive features, such as teeth and tails, that do appear in ancestral forms.Anatomically similar structures inherited from a common ancestor are called homologous structures.
12predicts that features of ancestors that no Chapter 15Evolution15.2 Evidence of EvolutionVestigial StructuresStructures that are the reduced forms of functional structures in other organisms.Evolutionary theorypredicts that features of ancestors that nolonger have a function for that species willbecome smaller over time until they are lost.
14Chapter 15Evolution15.2 Evidence of EvolutionAnalogous structures can be used for the same purpose and can be superficially similar in construction, but are notinherited from acommon ancestor.Show that functionally similar features can evolve independently in similar environments
15Comparative Embryology Chapter 15Evolution15.2 Evidence of EvolutionComparative EmbryologyVertebrate embryos exhibit homologous structures during certain phases of development but become totally different structures in the adult forms.
16Comparative Biochemistry Chapter 15Evolution15.2 Evidence of EvolutionComparative BiochemistryCommon ancestry can be seen in the complex metabolic molecules that many different organisms share.
17Chapter 15Evolution15.2 Evidence of EvolutionComparisons of the similarities in these molecules across species reflect evolutionary patterns seen in comparative anatomy and in the fossil record.Organisms with closely related morphological features have more closely related molecular features.
18Geographic Distribution Chapter 15Evolution15.2 Evidence of EvolutionGeographic DistributionThe distribution of plants and animals that Darwin saw first suggested evolution to Darwin.RabbitMara
19Evolution is intimately linked with climate and geological forces. Chapter 15Evolution15.2 Evidence of EvolutionPatterns of migration were critical to Darwin when he was developing his theory.Evolution is intimately linked with climate and geological forces.
20Chapter 15Evolution15.2 Evidence of EvolutionTypes of AdaptationAn adaptation is a trait shaped by natural selection that increases an organism’s reproductive success.Fitness is a measure of the relative contribution an individual trait makes to the next generation.
21Allows organisms to become almost invisible to predators Chapter 15Evolution15.2 Evidence of EvolutionCamouflageAllows organisms to become almost invisible to predatorsLeafy sea dragon
22One species evolves to resemble another species. Chapter 15Evolution15.2 Evidence of EvolutionMimicryOne species evolves to resemble another species.Western coral snakeCalifornia kingsnake
23Consequences of Adaptations Chapter 15Evolution15.2 Evidence of EvolutionConsequences of AdaptationsSome features of an organism might be consequences of other evolved characteristics.They do not increase reproductive success.Features likely arose as an unavoidable consequence of prior evolutionary change.
2415.3 Shaping Evolutionary Theory Chapter 15Evolution15.3 Shaping Evolutionary TheoryMechanisms of EvolutionPopulation geneticsHardy-Weinberg principle states that when allelic frequencies remain constant, a population is in genetic equilibrium.
25Homozygous dominant (p2) Chapter 15Evolution15.3 Shaping Evolutionary TheoryThis equation allows us to determine the equilibrium frequency of each genotype in the population.Homozygous dominant (p2)Heterozygous (2pq)Homozygous recessive (q2)
2615.3 Shaping Evolutionary Theory Chapter 15Evolution15.3 Shaping Evolutionary Theory
28Chapter 15Evolution15.3 Shaping Evolutionary TheoryGenetic DriftA change in the allelic frequencies in a population that is due to chanceIn smaller populations, the effects of genetic drift become more pronounced, and the chance of losing an allele becomes greater.
29Chapter 15Evolution15.3 Shaping Evolutionary TheoryFounder EffectOccurs when a small sample of a population settles in a location separated from the rest of the populationAlleles that were uncommon in the original population might be common in the new population.
30Chapter 15Evolution15.3 Shaping Evolutionary TheoryBottleneckOccurs when a population declines to a very low number and then rebounds
31Chapter 15Evolution15.3 Shaping Evolutionary TheoryGene FlowIncreases genetic variation within a population and reduces differences between populationsNonrandom MatingPromotes inbreeding and could lead to a change in allelic proportions favoring individuals that are homozygous for particular traits
32Chapter 15Evolution15.3 Shaping Evolutionary TheoryNatural SelectionActs to select the individuals that are best adapted for survival and reproduction
33Chapter 15Evolution15.3 Shaping Evolutionary TheoryStabilizing selection operates to eliminate extreme expressions of a trait when the average expression leads to higher fitness.
34Directional selection makes an organism more fit. Chapter 15Evolution15.3 Shaping Evolutionary TheoryDirectional selection makes an organism more fit.
35Chapter 15Evolution15.3 Shaping Evolutionary TheoryDisruptive selection is a process that splits a population into two groups.
36Chapter 15Evolution15.3 Shaping Evolutionary TheorySexual selection operates in populations where males and females differ significantly in appearance.Qualities of sexual attractiveness appear to be the opposite of qualities that might enhance survival.Natural Selection
37Chapter 15Evolution15.3 Shaping Evolutionary TheoryPrezygotic isolation prevents reproduction by making fertilization unlikely.Prevents genotypes from entering a population’s gene pool through geographic, ecological, behavioral, or other differencesEastern meadowlark and Western meadowlark
38Postzygotic isolation occurs when fertilization has occurred but Chapter 15Evolution15.3 Shaping Evolutionary TheoryPostzygotic isolation occurs when fertilizationhas occurred buta hybrid offspringcannot developor reproduce.Prevents offspring survival or reproductionLiger
39Allopatric Speciation Chapter 15Evolution15.3 Shaping Evolutionary TheoryAllopatric SpeciationA physical barrier divides one population into two or more populations.Abert squirrelKaibab squirrel
40A species evolves into a new species without a physical barrier. Chapter 15Evolution15.3 Shaping Evolutionary TheorySympatric SpeciationA species evolves into a new species without a physical barrier.The ancestor species and the new species live side by side during the speciation process.
4115.3 Shaping Evolutionary Theory Chapter 15Evolution15.3 Shaping Evolutionary TheoryAdaptive RadiationCan occur in a relatively short time when one speciesgives rise tomany differentspecies inresponse to thecreation of newhabitat or someother ecologicalopportunityFollows large-scale extinction events
42Coevolutionary arms race Chapter 15Evolution15.3 Shaping Evolutionary TheoryCoevolutionThe relationship between two species might be so close that the evolution of one species affects the evolution of the other species.MutualismCoevolutionary arms race
43Chapter 15Evolution15.3 Shaping Evolutionary TheoryConvergent EvolutionUnrelated species evolve similar traits even though they live in different parts of the world.
45Chapter 15Evolution15.3 Shaping Evolutionary TheoryRate of SpeciationEvolution proceeds in small, gradual steps according to a theory called gradualism.Punctuated equilibrium explains rapid spurts of genetic change causing species to diverge quickly.
4615.3 Shaping Evolutionary Theory Chapter 15Evolution15.3 Shaping Evolutionary Theory
48Chapter Resource Menu Chapter Diagnostic Questions EvolutionChapter Resource MenuChapter Diagnostic QuestionsFormative Test QuestionsChapter Assessment QuestionsStandardized Test Practicebiologygmh.comGlencoe Biology TransparenciesImage BankVocabularyAnimationClick on a hyperlink to view the corresponding lesson.
49Which is not a principle of Darwin’s theory about Chapter 15EvolutionChapter Diagnostic QuestionsWhich is not a principle of Darwin’s theory aboutthe origin of species?Individuals show variations.Variations can be inherited.Organisms have more offspring thanavailable resources will support.Offspring always inherit the best traits.
50Identify the term that is used to describe Chapter 15EvolutionChapter Diagnostic QuestionsIdentify the term that is used to describeanatomically similar structures inherited froma common ancestor.ancestral traitsanalogous structureshomologous structuresvestigial structures
51Which is not a vestigial structure? Chapter 15EvolutionChapter Diagnostic QuestionsWhich is not a vestigial structure?snake pelvisKiwi wingsporpoise flipperhuman appendix
52Which was Charles Darwin’s only qualification Chapter 15Evolution15.1 Formative QuestionsWhich was Charles Darwin’s only qualificationfor his position as naturalist on the Beagle?a degree in theologyan interest in sciencea knowledge of biologyan understanding of geology
53What was Darwin’s term for selective breeding? Chapter 15Evolution15.1 Formative QuestionsWhat was Darwin’s term for selective breeding?evolutionspeciationartificial selectionnatural selection
54What did Darwin infer from his observations of artificial selection? Chapter 15Evolution15.1 Formative QuestionsWhat did Darwin infer from his observations ofartificial selection?Animal breeders could create new species.A similar process could work in nature.Reproductive success could be increased.Variation in a species could be produced.
55What is the relationship between the terms Chapter 15Evolution15.1 Formative QuestionsWhat is the relationship between the termsnatural selection and evolution?They mean the same thing.Evolution works against natural selection.Evolution explains how natural selectionworks.Natural selection explains how evolutionworks.
56The Archaeopteryx seems to have evolved from Chapter 15Evolution15.2 Formative QuestionsTrue or FalseThe Archaeopteryx seems to have evolved fromreptiles and is a direct ancestor of modern birds.
57Which is an example of a derived trait? Chapter 15Evolution15.2 Formative QuestionsWhich is an example of a derived trait?a tailbonesfeathersteeth
58Which features are similar in use and evolve in Chapter 15Evolution15.2 Formative QuestionsWhich features are similar in use and evolve insimilar environments, but do not evolve from acommon ancestor?analogous structuresembryological structureshomologous structuresvestigial structures
59Organisms with similar anatomy share similar DNA sequences. Chapter 15Evolution15.2 Formative QuestionsTrue or FalseOrganisms with similar anatomy sharesimilar DNA sequences.
60At the heart of the theory of evolution by natural Chapter 15Evolution15.2 Formative QuestionsAt the heart of the theory of evolution by naturalselection lies the concept of __________.adaptationbiogeographygradualismspeciation
61The development of the evolutionary theory has Chapter 15Evolution15.3 Formative QuestionsThe development of the evolutionary theory hasled to the understanding that the raw materialfor evolution is _________.genestraitsadaptationcompetition
62Why does the ratio of gray to red owls remain Chapter 15Evolution15.3 Formative QuestionsWhy does the ratio of gray to red owls remainthe same after the population has doubled?
63They each have different predators. Chapter 15Evolution15.3 Formative QuestionsThey each have different predators.They compete with one another for resources.Both are equally adapted to survive in theirenvironment.New individuals have emigrated into thepopulation.
64Which of these conditions can act on Chapter 15Evolution15.3 Formative QuestionsWhich of these conditions can act onphenotypes to provide adaptive advantagesto a population?mutationsnatural selectionnonrandom matingsmall population size
65Which description is evidence that a speciation has taken place? Chapter 15Evolution15.3 Formative QuestionsWhich description is evidence that aspeciation has taken place?
66A physical barrier has caused two groups from a Chapter 15Evolution15.3 Formative QuestionsA physical barrier has caused two groups from apopulation to adapt to different environments.Some members can no longer produce fertileoffspring with members of the original population.A small group has developed mating behaviors thatare different than those of the rest of the population.Some members from a population have developedphysical characteristics that are different than theoriginal population.
67Which evolutionary pattern is represented by Chapter 15Evolution15.3 Formative QuestionsWhich evolutionary pattern is represented bythe similarities between these two organismsthat live on separate continents?coevolutionconvergent evolutiondirectional evolutiondivergent evolution
68Determine which morphological adaptation the Chapter 15EvolutionChapter Assessment QuestionsDetermine which morphological adaptation themonarch butterfly exhibits.camouflagemimicryembryological adaptationvestigial structure
69The divergent evolution of these cichlid fish is Chapter 15EvolutionChapter Assessment QuestionsThe divergent evolution of these cichlid fish isan example of what type of speciation?coevolutionmutationadaptive radiationconvergent evolution
70What tempo of evolution does this model represent? Chapter 15EvolutionChapter Assessment QuestionsWhat tempo of evolution does this modelrepresent?gradualelevatedsequentialpunctuated
71Which explains why the tortoises on the different Chapter 15EvolutionStandardized Test PracticeWhich explains why the tortoises on the differentislands of the Galápagos had slightly differentvariations in their shells?The different tortoises were different species.The environment on each island was different.Each type of tortoise could survive only on itsown island.They arrived on the islands from differentcontinents.
72Which is the best explanation for the similarities in Chapter 15EvolutionStandardized Test PracticeWhich is the best explanation for the similarities inthe construction of these forelimbs?Each forelimb is a similar modification derivedfrom a different ancestor.Natural selection has produced similarmodifications in the forelimb.
73Which is the best explanation for the similarities in Chapter 15EvolutionStandardized Test PracticeWhich is the best explanation for the similarities inthe construction of these forelimbs?They are functionally similar features that haveevolved independently.They are modifications of the forelimbs of acommon ancestor.
74Predators learn to avoid monarch butterflies Chapter 15EvolutionStandardized Test PracticePredators learn to avoid monarch butterfliesbecause they contain a poison that is distastefuland can cause the predator to get sick. The viceroybutterfly finds protection by closely resembling themonarch. What is this adaptation in the viceroycalled?camouflagefitnessmimicryresemblance
75Why are cheetahs so genetically similar that they appear inbred? Chapter 15EvolutionStandardized Test PracticeWhy are cheetahs so genetically similar that theyappear inbred?Individuals in the population had matedrandomly.Their population had declined to a very lownumber.A large sample of the population settled in aseparate location.A mutation appeared and became common insubsequent generations.
76Within a population of squirrels, those that Chapter 15EvolutionStandardized Test PracticeWithin a population of squirrels, those thatlive higher in the mountains where it iscooler have long fur. Squirrels that live inthe foothills where it is warmer have shortfur. The original population is believed tohave had intermediate fur length. Whichgraph represents this type of naturalselection?
77Standardized Test Practice Chapter 15EvolutionStandardized Test Practice
78These cichlid fish are believed to have diverged Chapter 15EvolutionStandardized Test PracticeThese cichlid fish are believed to have divergedfrom a single ancestor. What type of speciationis represented by this divergence?adaptive radiationallopatric speciationconvergent evolutiondisruptive coevolution