Evolution Library: Topic Page

Adaptation and Natural Selection

Natural selection is the cornerstone of Darwin's theory of evolution; adaptations are the traits that allow organisms to survive the selection process. This set of resources includes books, articles, and Web links that explore various aspects of these pivotal interrelated concepts.

Featured Multimedia Resources

Coral Reef Connections Dive in and explore what makes this beautiful world so fragile. Discover how coevolution has shaped the ecological relationships among reef creatures. Resource Type: Web Activity	Sex and the Single Guppy Play in our streams and see how exhibitionism has an evolutionary payoff in this simulation of Endler's experiment. Resource Type: Web Activity	The Mating Game Help our contestants pass their genes down the evolutionary line as you discover the varied mating behaviors of living things. Resource Type: Web Activity

Adaptation
	Resource	Type	Format	Topics Covered

	Evolution of Camouflage This segment from Evolution: "Darwin's Dangerous Idea" illustrates the remarkable camouflage of a praying mantis against its leafy backdrop.	Video	QuickTime or RealPlayer get plug-in	Adaptation and Natural Selection

	Evolution of the Eye Zoologist Dan-Erik Nilsson demonstrates how the complex human eye could have evolved from simple light-sensitive cells. From Evolution: "Darwin's Dangerous Idea."	Video	QuickTime or RealPlayer get plug-in	Adaptation and Natural Selection

	Is Intelligent Life Inevitable? Does intelligence have to look human? Decide for yourself in this poll.	Web Activity	Web Activity	Adaptation and Natural Selection

	How the Woodpecker Avoids a Headache This diagram describes the specialized functions and structures that allow a woodpecker to live off insects burrowed in trees.	Image	Graphic	Adaptation and Natural Selection

	Mimicry: The Orchid and the Bee In this photograph, a horned bee attempts to mate with an Ophrys orchid, which has evolved to resemble a female bee.	Image	Graphic	Adaptation and Natural Selection

	Adaptation This online encyclopedia entry provides a good starting point for the beginner interested in exploring the concept of evolutionary adaptation. Hosted by Encarta.com.	External Link	HTML	Adaptation and Natural Selection

	Adaptation Lecture This page, developed as part of an undergraduate course in evolution at the University of Chicago, does an exemplary job of distinguishing between adaptations, preadaptations, spandrels, and exaptations.	External Link	HTML	Adaptation and Natural Selection

	Coloration This site, part of an undergraduate course, neatly outlines the different types of coloration found in various animal species and briefly discusses some of their consequences. Hosted by Buffalo State College.	External Link	HTML	Adaptation and Natural Selection

	Contrivances: Orchids and the Panda's Thumb This activity explores how many features of modern organisms reflect the structure of their ancestors. Hosted by ENSI at the University of Indiana.	External Link	HTML	Adaptation and Natural Selection

	Mimicry This page offers succinct explanations of the three types of mimicry: Batesian, Mullerian, and aggressive. By M. Tevfik Dorak.	External Link	HTML	Adaptation and Natural Selection

	Natural Selection This link offers an introduction to many of the key ideas in population genetics, including the founder effect and the genetic basis for natural selection. Hosted by La Trobe University, Australia.	External Link	HTML	Adaptation and Natural Selection

	Planet Ocean Targeted to students in grades 5-8, this site provides a brief introduction to a few ocean zones and their inhabitants, including blue whales and tubeworms. Links will take teachers to teaching tips and additional curriculum resources, in the form of books and Web sites. Hosted by DiscoverySchool.com.	External Link	HTML	Adaptation and Natural Selection

	The Peppered Moth - An Update This link provides an update on new research casting some doubts on the classic example of natural selection on the peppered moth. British ecologist H.B.D. Kettlewell's original study was a bit flawed, though most of his conclusions still seem to stand. Further updates will appear at this site. Hosted by Brown University.	External Link	HTML	Adaptation and Natural Selection

	The Spandrels of San Marco and the Panglossian Paradigm In this full-text article from the 1979 Proceedings of the Royal Society of London, Stephen Jay Gould and Richard Lewontin present their well-supported, though still controversial, argument against the notion that all phenotypic traits are adaptations. Hosted by the American Association for the Advancement of Science.	External Link	HTML	Adaptation and Natural Selection

	Climbing Mount Improbable In this book, the author provides a comprehensive account explaining that evolution occurs as a result of many small steps of change. Readers will also find elaborate discussions of the evolution of such things as spider webs, flight adaptations, and dozens of independently evolved eyes. By Richard Dawkins [New York: W.W. Norton & Co., 1996].	Other Resources	Print	Adaptation and Natural Selection

	Evolutionary Biology, 3rd ed. An excellent college-level textbook for the serious student of modern evolutionary theory. Chapter 13 explains the three basic types of natural selection and their effects. The related concept of sexual selection is discussed in chapter 20. By Douglas J. Futuyma [Sunderland, Mass.: Sinauer Associates, Inc., 1998].	Other Resources	Print	Adaptation and Natural Selection

Adaptive Compromise
	Resource	Type	Format	Topics Covered

	A Mutation Story This segment describes the role of the sickle cell gene in natural selection. Footage courtesy of the PBS series Secret of Life: "Accidents of Creation."	Video	QuickTime or RealPlayer get plug-in	Adaptation and Natural Selection

	Shape of Trees: The Frustration Principle This series of images shows the work of biologist Karl Niklas on the adaptations and evolution of plants.	Image	Graphic	Adaptation and Natural Selection

	Constraints and Trade-offs in Evolution This essay discusses the role of adaptive constraint in shaping the evolutionary path that organisms can or cannot take. Primary literature references are not included. Hosted by Brown University.	External Link	HTML	Adaptation and Natural Selection

	Death by Design This lengthy but interesting exposition argues for a non-mainstream view that the processes of senescence and death have explicitly evolved to promote genetic and phenotypic diversity of populations, which enhances the long-term fitness of the group. The logic is fairly well-grounded, but beware of the author's somewhat anthropomorphized use of the word "evolution." Hosted by the University of Chicago.	External Link	HTML	Adaptation and Natural Selection

	Evidence for Jury-Rigged Design in Nature This article explains how phenotypic constraints can be imposed by the evolutionary history (phylogeny) of a species. After the introduction, there are lists of examples of these "maladapted" organisms and descriptions of the elaborate tactics some must employ to get around their handicaps. Hosted by Talk.Origins.	External Link	HTML	Adaptation and Natural Selection

	Evolution and the Origins of Disease This full-text Scientific American article, written by Randolph M. Nesse and George C. Williams in 1998, describes the newly evolved field of "Darwinian medicine" and discusses how many human afflictions are the result of evolutionary processes, including adaptive compromise.	External Link	HTML	Adaptation and Natural Selection

	Eye-opening Gene This article summarizes the new findings that challenge the traditional view that eyes evolved independently in many animal lineages and includes a very focused bibliography of additional references. Hosted by Science News Online.	External Link	HTML	Adaptation and Natural Selection

	Plant Evolution: Adaptation or Historical Accident? This site discusses the author's computer model and research into the adaptation of land plants. By Karl Niklas. Hosted by Access Excellence.	External Link	HTML	Adaptation and Natural Selection

	Size and Shape This article, by Stephen Jay Gould, clearly explains how the basic features of size and shape impose constraints on other aspects of form and function in every organism. Hosted by the American Museum of Natural History.	External Link	HTML	Adaptation and Natural Selection

	Evolutionary Biology, 3rd ed. An excellent college-level textbook for the serious student of modern evolutionary theory. Chapter 13 explains the three basic types of natural selection and their effects. The related concept of sexual selection is discussed in chapter 20. By Douglas J. Futuyma [Sunderland, Mass.: Sinauer Associates, Inc., 1998].	Other Resources	Print	Adaptation and Natural Selection

	Hen's Teeth and Horse's Toes In this collection of essays, the author clearly explains how structural and functional limitations, phylogeny, and natural selection together impose design constraints on organisms. These constraints have produced a wide array of less-than-perfect, and sometimes quite bizarre, features. By Stephen Jay Gould [New York: W.W. Norton & Co., 1983].	Other Resources	Print	Adaptation and Natural Selection

	The Evolution of Complexity by Means of Natural Selection In this book, the author makes a clear, if technical, argument for the evolution of biological complexity among certain groups of organisms, citing design constraints imposed by physical and chemical laws as important drivers of such evolution. By John Bonner [Princeton, N.J.: Princeton University Press, 1998].	Other Resources	Print	Adaptation and Natural Selection

	The Panda's Thumb: More Reflections in Natural History In this essay, the author describes the anatomy and origin of the panda's thumb, which is not really a thumb at all, as an illustration of how imperfections in design can sometimes offer the best evidence for evolution. By Stephen Jay Gould [New York: W.W. Norton & Co., 1980].	Other Resources	Print	Adaptation and Natural Selection

Coevolution
	Resource	Type	Format	Topics Covered

	Coral Reef Connections Dive in and explore what makes this beautiful world so fragile. Discover how coevolution has shaped the ecological relationships among reef creatures.	Web Activity	Flash get plug-in	Adaptation and Natural Selection

	Ancient Farmers of the Amazon This segment from Evolution: "Evolutionary Arms Race" tells the story of the leafcutter ant and the fungus it farms -- an example of mutually beneficial symbiosis.	Video	QuickTime or RealPlayer get plug-in	Adaptation and Natural Selection

	Toxic Newts The father and son team of Brodie and Brodie track down the predator able to stomach a mysteriously hyper-toxic newt, an example of an evolutionary arms race in action. From Evolution: "Evolutionary Arms Race."	Video	QuickTime or RealPlayer get plug-in	Adaptation and Natural Selection

	The Advantage of Sex Why did sex evolve? The likely answers, in this essay by science journalist Matt Ridley, may surprise you.	Web Activity	Web Activity	Adaptation and Natural Selection

	Mollusk Defenses This collage illustrates numerous defenses ancient and modern mollusks use against their predators.	Image	Graphic	Adaptation and Natural Selection

	E.O. Wilson: Ants and Ecosystems This segment is from an interview with ant specialist and biologist E.O. Wilson, filmed for Evolution: "Evolutionary Arms Race."	Interview	Audio get plug-in	Adaptation and Natural Selection

	E.O. Wilson: The World of Microbes In this interview excerpt filmed for Evolution: "Evolutionary Arms Race," biologist E.O. Wilson discusses the interaction of species and the vital roles that microbes play in life on Earth.	Interview	Audio get plug-in	Adaptation and Natural Selection

	Fitness and Synergy This fairly technical paper explains the often ill-defined or tautological concept of fitness, then argues that organisms can improve their fitness more by cooperative interactions (such as mutualism) than by antagonistic ones (such as parasitism). Hosted by CALResCo.	External Link	HTML	Adaptation and Natural Selection

	How Parasitic Wasps Find their Hosts This article explains in detail how plants, such as corn, release volatile chemicals when damaged by herbivores. These chemicals in turn act as attractants for parasitic wasps, which can follow the scent trails to the plants, where they use the herbivores as hosts for their offspring. By James H. Tumlinson, W. Joe Lewis, and Louise E. M. Vet [Scientific American, March 1993, 100-106].	Other Resources	Print	Adaptation and Natural Selection

	Insects and Flowers This book explains the variety of relationship that have coevolved between insects and flowers. By Friedrich G. Barth in 1985 and translated for this edition by M.A. Biederman-Thorson [Reprint, Princeton, N.J.: Princeton University Press, 1991].	Other Resources	Print	Adaptation and Natural Selection

	Symbiosis in the Deep Sea This article explains how the surprising density of life at seemingly inhospitable deep-sea hydrothermal vents depends on symbiotic relationships that have coevolved between various invertebrates and their colonizing bacteria. By James J. Childress, Horst Felbeck, and George N. Somero [Scientific American, May 1987, 114].	Other Resources	Print	Adaptation and Natural Selection

	The Coevolutionary Process In this book, the author expounds on a new approach toward studying coevolution, called geographical mosaic theory of coevolution. This book contains a wealth of information, beginning with a history of and introduction to the field of evolutionary ecology and contains a bibliography of more than 1,000 references. By John N. Thompson [Chicago: University of Chicago Press, 1994].	Other Resources	Print	Adaptation and Natural Selection

	Yellow Fever, Black Goddess: The Coevolution of People and Plagues Intended for an audience with at least a college-level understanding of genetics and evolutionary biology, this book discusses in great detail the adaptations infectious agents have made in coevolving with their human hosts. By Christopher Wills [Cambridge, Mass.: Perseus Publishing, 1997].	Other Resources	Print	Adaptation and Natural Selection

Convergent Evolution
	Resource	Type	Format	Topics Covered

	Convergent Evolution This diagram illustrates convergent evolution, the process by which species evolved in different parts of the globe independently. They share similar traits and fill similar niches, but they occupy different continents.	Image	Graphic	Adaptation and Natural Selection

	Convergence: Marsupials and Placentals This graphic illustrates some of the marsupial mammals in Australia and placental mammals in North America. Even though they are not closely related, these mammals look alike because they have adapted to similar ecological roles.	Document	PDF get plug-in	Adaptation and Natural Selection

	Australian Fauna This site provides a brief account of the evolutionary history of the three main groups of mammals (monotremes, marsupials, placentals). A simple table comparing placental and marsupial species that have evolved in parallel is also included.	External Link	HTML	Adaptation and Natural Selection

	Birds and DNA Using photos of a variety of bird species, this site explains how grouping organisms on the basis of appearance can lead to errors in phylogenetic determination, while groupings based on DNA sequence analysis can "see past" convergently evolved morphologies to give accurate phylogenies. Hosted by Museum Victoria.	External Link	HTML	Adaptation and Natural Selection

	Natural Born Robots: Swim Like a Fish This archived PBS teaching guide (companion to a Scientific American Frontiers video) explains how engineers are borrowing designs from nature to build robots that swim like fish. Follow links to additional resources and classroom exercises appropriate for grades 5-12. Hosted by PBS.	External Link	HTML	Adaptation and Natural Selection

	Shaking the Family Tree This site describes two recent studies on the relationships between the various species of placental mammals that have evolved in parallel for millions of years and provides references for the original papers. Only subscribers can view full-text articles online. Hosted by Nature.com.	External Link	HTML	Adaptation and Natural Selection

	The Three Solutions to Flight This site provides an overview of convergence in adaptations for flight and links to individual discussions that thoroughly explain how each group has taken wing. Hosted by the University of California Museum of Paleontology.	External Link	HTML	Adaptation and Natural Selection

	When Evolution Creates the Same Design Again and Again This site contains a full-text reprint of a New York Times article on the topic of convergent evolution. Some interesting examples of convergent features are cited, followed by a thorough discussion of the causes and consequences of convergence. Hosted by the Cleveland Museum of Natural History.	External Link	HTML	Adaptation and Natural Selection

	Function, Phylogeny, and Fossils: Miocene Hominoid Evolution and Adaptations Written by 22 specialists for an advanced audience, this volume discusses the adaptations and phylogenetic relationships among the Hominoidea superfamily. The book also provides excellent general discussions of patterns and processes in parallel and convergent evolution. Edited by David R. Begun, Carol V. Ward, and Michael D. Rose [New York: Plenum Press, 1997].	Other Resources	Print	Adaptation and Natural Selection

Heritable Variation
	Resource	Type	Format	Topics Covered

	Asexual Reproducers This segment explores the benefits and pitfalls of cloning as a means of reproduction. From Evolution: "Why Sex?"	Video	QuickTime or RealPlayer get plug-in	Adaptation and Natural Selection

	The Red Queen An example of the Red Queen hypothesis, the sexual population of Mexican Poeciliid fish are able to keep up with a changing environment, while the asexual populations are not as successful. From Evolution: "Why Sex?"	Video	QuickTime or RealPlayer get plug-in	Adaptation and Natural Selection

	Evolution of the Dog Images of different breeds of dogs. Domesticated dogs provide an example of humans acting as natural "selectors," shaping different types for different purposes.	Image	Graphic	Adaptation and Natural Selection

	Variation: Snails This image shows the variation in shell pattern and color within a single species of tree snail.	Image	Graphic	Adaptation and Natural Selection

	Are Mutations Harmful? This site presents the current understanding of genetic mutations, including types, mechanisms, and effects. The bibliography of original research papers is extensive. Hosted by Talk.Origins.	External Link	HTML	Adaptation and Natural Selection

	On the Tendency of Varieties to Depart Indefinitely This site includes the full-text, original version of Alfred Russel Wallace's 1858 manuscript in which he argues that different varieties, and ultimately species, can evolve from a single parent species. Even though Wallace does not explicitly mention inheritance, his argument relies on the concept. Hosted by the University of Bergen, Norway.	External Link	HTML	Adaptation and Natural Selection

	Online Mendelian Inheritance In Animals (OMIA) This up-to-date searchable catalog describes the genes that influence phenotypic traits of animals, from alpacas to zebrafish. Search by species or traits/disorders. Hosted by the Australian National Genomic Information Service.	External Link	HTML	Adaptation and Natural Selection

	Online Mendelian Inheritance In Man (OMIM) This searchable catalog offers highly technical and detailed information about human genes and genetic disorders. Search results are summaries of recent scientific publications that provide information about the genes influencing a phenotypic trait, and accompanying links lead to maps of the chromosomal location of the genes of interest. Hosted by the National Center for Biotechnology Information.	External Link	HTML	Adaptation and Natural Selection

	Origin, Adaptation, and Types of Corn This site is a compendium of research summaries (primary sources are not cited on the page) detailing the evolutionary history of corn, as well as the varieties that currently exist throughout the world. Hosted by the University of Maryland.	External Link	HTML	Adaptation and Natural Selection

	Quantitative Genetics/Polygenic Inheritance - Going from simple to complicated Intended for a specialist audience, this site discusses the difficulties associated with quantifying the heritability of traits and considers influences (including polygenic and environmental effects) that can complicate calculations. Hosted by the University of Glasgow.	External Link	HTML	Adaptation and Natural Selection

	Random Genetic Drift This article is an excellent summary of current knowledge on genetic drift, a major omission from Darwin's original theory and an important mechanism of evolution. Hosted by Talk.Origins.	External Link	HTML	Adaptation and Natural Selection

	Variation Under Domestication This site includes chapter 1 of Charles Darwin's On the Origin of Species, in which he explains heritable variations seen among domesticated plant and animal species. Hosted by literature.org.	External Link	HTML	Adaptation and Natural Selection

	Variation Under Nature This site includes chapter 2 of Charles Darwin's On the Origin of Species, in which he discusses phenotypic variations observed among non-domesticated species. Hosted by literature.org.	External Link	HTML	Adaptation and Natural Selection

	Evolutionary Biology, 3rd ed. An excellent college-level textbook for the serious student of modern evolutionary theory. Chapter 13 explains the three basic types of natural selection and their effects. The related concept of sexual selection is discussed in chapter 20. By Douglas J. Futuyma [Sunderland, Mass.: Sinauer Associates, Inc., 1998].	Other Resources	Print	Adaptation and Natural Selection

	Inheritance in Dogs Written in layman's terms, this book thoroughly describes the principles of genetic inheritance in dogs. It's an excellent reference for dog breeders and owners of purebreds, which are most likely to exhibit hereditary dysfunctions. By Ojvind Winge [Ithaca, N.Y.: Comstock Publishing Co., 1950].	Other Resources	Print	Adaptation and Natural Selection

Natural and Sexual Selection
	Resource	Type	Format	Topics Covered

	Sex and the Single Guppy Play in our streams and see how exhibitionism has an evolutionary payoff in this simulation of Endler's experiment.	Web Activity	Shockwave get plug-in	Adaptation and Natural Selection

	The Mating Game Help our contestants pass their genes down the evolutionary line as you discover the varied mating behaviors of living things.	Web Activity	Flash get plug-in	Adaptation and Natural Selection

	Jacanas and Polyandry In response to the threat of crocodiles, female wattled jacanas have evolved an unusual reproductive strategy: polyandry, or "many males." From Evolution: "Why Sex?"	Video	QuickTime or RealPlayer get plug-in	Adaptation and Natural Selection

	Songbird Infidelity Female songbirds take a chance when they are non-monogamous, but their offspring benefit from the genetic variation -- they have a better survival rate. From Evolution: "Why Sex?"	Video	QuickTime or RealPlayer get plug-in	Adaptation and Natural Selection

	Sweaty T-Shirts and Human Mate Choice This segment from Evolution: "Why Sex?" explores the "sweaty T-shirt experiment," which showed that humans may unconsciously be drawn toward a specific kind of genetic variation in a mate.	Video	QuickTime or RealPlayer get plug-in	Adaptation and Natural Selection

	Tale of the Peacock The peacock provides a classic example of sexual selection, the force behind nature's extravagances. From Evolution: "Why Sex?"	Video	QuickTime or RealPlayer get plug-in	Adaptation and Natural Selection

	Adaptive Radiation: Darwin's Finches Finches on the Galapagos Islands have evolved to exploit almost every possible niche. This diagram shows the range of food sources available on the island and the different beak shapes adapted to exploit each of them.	Image	Graphic	Adaptation and Natural Selection

	Bachelor Uncles In this image a peacock displays for a peahen. Male peacocks work together to attract females in communal mating groups.	Image	Graphic	Adaptation and Natural Selection

	Mantis Mating This sequence of images from film shot for Evolution: "Why Sex?" shows a female praying mantis eating a male after mating.	Image	Graphic	Adaptation and Natural Selection

	Paul Ewald: Infectious Disease and the Evolution of Virulence In these interview transcript excerpts from Evolution: "The Evolutionary Arms Race," Dr. Paul Ewald discusses applying principles of evolution to reduce the harm of infectious diseases.	Interview	Text	Adaptation and Natural Selection

	Finch Beak Data Sheet This graphic presents data from the Galapagos Islands, showing that a severe drought put selective pressure on the population of Darwin's finches and resulted in a change in the average beak size in the next generation.	Document	PDF get plug-in	Adaptation and Natural Selection

	Evolution in Action This interactive feature shows how random mutations can lead to species-wide change. The "world" presented in this feature is abstract -- colored creatures placed within a colored environment. The user can change the environment ( the background color) and observe how these changes affect the survival and reproduction of the different "creatures".	External Link	HTML	Adaptation and Natural Selection

	Evolution and Chance This site addresses the frequently misunderstood role of chance, or random mutation and genetic drift, in evolution and also discusses the importance of natural selection and genetic inheritance. Hosted by Talk.Origins.	External Link	HTML	Adaptation and Natural Selection

	How Females Choose Their Mates This entertaining and clearly written article explains in detail how females select mates, citing examples from the primary literature. Hosted by Scientific American.	External Link	HTML	Adaptation and Natural Selection

	Morph Lab Starting with an assortment of artificial life forms, this game lets you choose which life form survives after each round, simulating the role of natural selection in evolution. A background on how evolution takes place in the game is included in the instructions. Hosted by fusebox.com.	External Link	HTML	Adaptation and Natural Selection

	Natural Selection In chapter 4 of On the Origin of Species, Charles Darwin masterfully explains the effects of natural (including sexual) selection on species variants, logically arguing how selection could produce a structure as complex as the vertebrate eye. Hosted by literature.org.	External Link	HTML	Adaptation and Natural Selection

	Natural Selection: Modes of Selection This tutorial offers definitions of directional, disruptive, and stabilizing selection, as well as a simulation that shows how each selection type affects a population of colored dots over time. Hosted by EvoTutor.org.	External Link	HTML	Adaptation and Natural Selection

	Struggle for Existence In this chapter of On the Origin of Species, Charles Darwin outlines the mechanisms underlying natural selection. Hosted by literature.org.	External Link	HTML	Adaptation and Natural Selection

	The Case of the Irish Elk This article describes and shows fossil images of the extinct Irish elk, whose immense antlers are thought to have been a product of sexual selection. Hosted by the University of California Museum of Paleontology.	External Link	HTML	Adaptation and Natural Selection

	Adaptation and Natural Selection This classic book clearly rebutted the notion of group (versus individual) selection, which had become a serious challenge to Darwinian theory. By George C. Williams [Princeton, N.J.: Princeton University Press, 1966].	Other Resources	Print	Adaptation and Natural Selection

	Ecology and Evolution of Darwin's Finches This classic book details the findings of Peter and Rosemary Grant, who made firsthand observations of the evolution of Darwin's finches on the Galapagos Islands. By Peter Grant [Princeton, N.J.: Princeton University Press, 1986].	Other Resources	Print	Adaptation and Natural Selection

	Natural Selection: Domains, Levels, and Challenges In this book written for advanced students of evolutionary biology, the author provides a technical discussion of the theoretical issues of selection. By George C. Williams [Cambridge: Oxford University Press, 1992].	Other Resources	Print	Adaptation and Natural Selection

	The Beak of the Finch This book is a beautifully written chronicle of more than three decades of study of evolution observed firsthand among the Galapagos finches. By Jonathan Weiner [New York: Vintage Books, 1999].	Other Resources	Print	Adaptation and Natural Selection