© Jones & Bartlett Learning, LLC © Jones & BartlettCHAPTER Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 4 Evolution© Jones &and Bartlett Learning, Extinction LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Chapter© Jones Themes & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION How did early theories of evolution differ from Darwin’s? What sorts of evidence led Darwin to his theory of evolution? How is genetic information stored and transmitted from parents to offspring? © Jones & WhatBartlett produces Learning, genetic LLC variation? © Jones & Bartlett Learning, LLC NOT FOR SALEWhat is OR the DISTRIBUTIONevidence for natural selection? NOT FOR SALE OR DISTRIBUTION How do new species and other groups originate? What is the evidence for evolution? How does extinction affect evolution? © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Chapter Outline © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 4.1 Introduction 4.9 Evolution and the Fossil Record 4.9.1 Comparative anatomy 4.2 Early Theories of Evolution 4.9.2 Cladistics BOX 4.1 Evolution of Biologic Classification 4.9.3 Microevolution and the Species Concept © Jones & Bartlett Learning, LLC © Jones4.9.4 & Bartlett Macroevolution Learning, LLC NOT FOR SALECharles OR DISTRIBUTION Darwin and the Beginnings of NOT FOR SALE OR DISTRIBUTION 4.3 Mass Extinction the Modern Theory of Evolution 4.10 BOX 4.2 Charles Darwin, the Person 4.11 Biodiversity Through the Phanerozoic Basic Premises of Darwinian Evolution 4.4 © Jones & Bartlett Learning, 4.12LLC Summary © Jones & Bartlett Learning, LLC BOX 4.3 Misuse of Darwin’s Theory NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 4.5 Inheritance and Variation 4.6 Genetic Code and Mutation 4.7© JonesEvidence & for Bartlett Natural Learning,Selection LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 4.8 Speciation © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 105 © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. developed and modified, leading to new questions. As © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC Introduction we will see, several of these questions stem from a better NOT FOR SALE4.1 OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Charles Darwin (1809–1882) is rightfully understanding of the fossil record: How do new species credited with founding the modern theory of evolu- arise? How do new anatomic structures like wings or tion because the basic foundation of the theory laid eyes and wholly new groups of organisms—like reptiles down by him has remained largely intact to the present. or mammals—arise? How do mass extinctions of the © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC Darwin’s theory supported, and was supported by, the biosphere—well documented in the fossil record— notion of deep timeNOT implicated FOR SALE by Hutton OR DISTRIBUTIONand Lyell create new evolutionary NOTopportunities? FOR SALE OR DISTRIBUTION (see Chapter 1). Recall from Chapter 1, however, that the view of Earth espoused by Lyell was one of strict Early Theories of Evolution equilibrium: no net change. But with Darwin’s theory 4.2 Two of Darwin’s predecessors, both French, came© Jones the growing & Bartlett realization Learning, that not LLC only has life stand out© for Jones their views & onBartlett evolution: Learning, Jean Baptiste LLC Pierre evolvedNOT FOR but so SALE too have OR Earth’s DISTRIBUTION physical systems. Natu- Antoine deNOT Monet, FOR Chevalier SALE de Lamarck,OR DISTRIBUTION or just Lamarck ral systems can exhibit directionality or secular change, (1744–1829), and Baron Georges Cuvier (1762–1839) because they are open systems, that is, they can evolve. (FIGURE 4.1). Lamarck originally believed that certain Darwin’s theory is therefore not only fundamental to groups of organisms—now called species—were fixed © Jones & Bartlettthe study Learning, of the history LLC and evolution of life but also© Jones and & did Bartlett not evolve, Learning, but began toLLC change his views as his NOT FOR SALEstrengthened OR DISTRIBUTION the inkling that physical systems—andNOT FORstudies SALE progressed OR DISTRIBUTION(BOX 4.1). Lamarck based his theory thus Earth—can evolve as well. of evolution on spontaneous generation which stated that Like so many theories, however, Darwin’s was living matter arises from nonliving matter. Lamarck based preceded by others. To fully comprehend the signifi- his acceptance of spontaneous generation on his observa- cance of the modern theory of evolution, we must ex- tion that the simplest organisms had no obvious organs, amine these earlier© theories. Jones In & doing Bartlett so we Learning,get another LLCso Lamarck reasoned they© must Jones have & evolved Bartlett directly Learning, LLC glimpse as to howNOT scientists FOR think SALE and how OR theories DISTRIBUTION are from nonliving substances.NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett(a) Learning, LLC © Jones(b) & Bartlett Learning, LLC NOT FOR SALEFIGURE OR 4.1 DISTRIBUTION(a) Jean Baptiste Pierre Antoine de Monet, ChevalierNOT de FOR Lamarck SALE (1744–1829). OR DISTRIBUTION (b) Baron Georges Cuvier (1762–1839). 106 CHAPTER 4 © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALEBOX OR4.1 DISTRIBUTION Evolution of Biologic Classification and the Species Concept A species is a group© of Jones organisms & thatBartlett interbreed Learning, with menclature,LLC and any species described© Jones before & thisBartlett time Learning, LLC one another and produceNOT fertileFOR offspring. SALE TORhe point DISTRIBUTION of are considered invalid. However,NOT species FOR originally SALE de -OR DISTRIBUTION reproduction is to propagate the species. Species are usu- scribed after 1758 may still be redescribed or placed ally recognized by physical features thought to reflect the in new groupings based on new data. identity of the species, such as anatomic traits, distinctive As evolutionary theory began to take hold, Linnaeus’ coloration, or behavior. Many species have “common” system of biologic classification began to take on a new names© Jones used by & lay Bartlett people. However, Learning, these terms LLC can be meaning: evolutionary© Jones relationships. & Bartlett A classification Learning, rec -LLC confusing,NOT FOR especially SALE if they OR are DISTRIBUTIONused to refer to different ognizes similaritiesNOT or FOR dissimilarities SALE between OR DISTRIBUTION objects, in species. To avoid confusion among scientists, each spe- this case species. The purpose of a biologic classification cies is given a scientific name consisting of two names: is to show evolutionary relationships, or phylogeny, the genus and the species. For example, the scientific between different groups of organisms, or taxa (taxon, singular). Biologic classification and phylogenetic rela- © Jones & Bartlettname of human Learning, beings is LLC Homo sapiens. Homo is the © Jones & Bartlett Learning, LLC tionships are hierarchies. These hierarchies consist of genus and sapiens is the species. The scientific name for NOT FOR SALE OR DISTRIBUTION NOTdifferent FOR levels,SALE or ORcategories—kingdom, DISTRIBUTION phylum, class, humans means “prescient man,” referring to the mental order, family, genus, and species—each of which may ability of humans to foresee into the future and anticipate be further subdivided or lumped together. The actual the consequences of their actions and those of nature. groups, or taxa (such as particular species), are placed By international convention the scientific name is always into higher taxa corresponding to the different categories; underlined or set off ©from Jones the surrounding & Bartlett text inLearning, some LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTIONthus, each taxon shares characteristicsNOT FOR with theSALE other OR DISTRIBUTION other manner, and the genus name is always capital- members of the same taxon. The science of biologic ized, whereas the species name is not (species is used classification is calledtaxonomy . A biologic classifica- for both the singular and plural; there is no such word tion is therefore like a series of boxes nested within as “specie”). Each genus is represented by one or more progressively larger boxes. In biologic classification these species.© Jones Thus, when& Bartlett referring Learning,to a particular speciesLLC one boxes are called© categoriesJones &with Bartlett the categories Learning, becoming LLC citesNOT both FOR names—genus SALE ORand species—not DISTRIBUTION just the spe- more and moreNOT inclusive. FOR T axaSALE and categories