Historical Context for Evolutionary Theory

         Western culture resisted evolutionary views of life
         Theories of geological gradualism helped clear the path for evolutionary
         biologists
         Lamarck placed fossils in an evolutionary context

    The Darwinian Revolution

         Field research helped Darwin frame his view of life: science as a process
         The Origin of Species developed two main points: the occurrence of
         evolution and natural selection as its mechanism

    Evidence of Evolution

         Evidence of evolution pervades biology
         What is theoretical about the Darwinian view of life?

Chapter  22
evolution All the changes that have transformed life on Earth from its earliest beginnings to the diversity that characterizes it today.
natural selection Differential success in the reproduction of different phenotypes resulting from the interaction of organisms with their environment. Evolution occurs when natural selection causes changes in relative frequencies of alleles in the gene pool.
*evolutionary adaptions
*natural theology
taxonomy The branch of biology concerned with naming and classifying the diverse forms of life.
*fossils
sedimentary rocks (SED-eh-MEN-tar-ee) Rock formed from sand and mud that once settled in layers on the bottom of seas, lakes, and marshes. Sedimentary rocks are often rich in fossils.
paleontology (PAY-lee-un-TOL-uh-jee) The scientific study of fossils.
*catastrophism
gradualism A view of Earth's history that attributes profound change to the cumulative product of slow but continuous processes.
*uniformitarianism
*descent with modification
artificial selection The selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits.

biogeography The study of the past and present distribution of species.
homology Similarity in characteristics resulting from a shared ancestry.
homologous structures Structures in different species that are similar because of common ancestry.
vestigial organs A type of homologous structure that is rudimentary and of marginal or no use to the organism.
ontogeny (on-TOJ-en-ee) The embryonic development of an organism.
phylogeny (fih-LOJ-en-ee) The evolutionary history of a species or group of related species.
 
 

    Population Genetics

         The modern evolutionary synthesis integrated Darwinian selection and
         Mendelian inheritance
         The genetic structure of a population is defined by its allele and genotype
         frequencies
         The Hardy-Weinberg theorem describes a nonevolving population

    Causes of Microevolution

         Microevolution is a generation-to-generation change in a population's allele
         or genotype frequencies
         The five causes of microevolution are genetic drift, gene flow, mutation,
         nonrandom mating, and natural selection

    Genetic Variation, the Substrate for Natural Selection

         Genetic variation occurs within and between populations
         Mutation and sexual recombination generate genetic variation
         Diploidy and balanced polymorphism preserve variation

    Natural Selection as the Mechanism of Adaptive Evolution

         Evolutionary fitness is the relative contribution an individual makes to the
         gene pool of the next generation
         The effect of selection on a varying characteristic can be stabilizing,
         directional, or diversifying
         Sexual selection may lead to pronounced secondary differences between
         the sexes Natural selection cannot fashion perfect organisms
 

Chapter  23
*population genetics
modern synthesis A comprehensive theory of evolution emphasizing natural selection, gradualism, and populations as the fundamental units of evolutionary change; also called neo-Darwinism.
populaiton A group of individuals of one species that live in a particular geographic area.
species A particular kind of organism; members possess similar anatomical characteristics and have the ability to interbreed.
*gene pool
*genetic structure
Hardy-Weinberg theorem An axiom maintaining that the sexual shuffling of genes alone cannot alter the overall genetic makeup of a population.
*Hardy-Weinberg  equilibrium
*Hardy-Weinberg equation
microeolution A change in the gene pool of a population over a succession of generations. microvillus (plural, microvilli) One of many fine, fingerlike projections of the epithelial cells in the lumen of the small intestine that increase its surface area.genetic drift Changes in the gene pool of a small population due to chance.
bottleneck effect Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer genetically representative of the original population.
*founder effect
gene flow The loss or gain of alleles from a population due to the emigration or immigration of fertile individuals, or the transfer of gametes, between populations.
mutation (myoo-TAY-shun) A rare change in the DNA of genes that ultimately creates genetic diversity.
*inbreeding
assortative mating A type of nonrandom mating in which mating partners resemble each other in certain phenotypic characters.
natural selection Differential success in the reproduction of different phenotypes resulting from the interaction of organisms with their environment. Evolution occurs when natural selection causes changes in relative frequencies of alleles in the gene pool.
polymorphism (POL-ee-MOR-fiz-um) The coexistence of two or more distinct forms of individuals (polymorphic characters) in the same population.
geographical variation
cline Variation in features of individuals in a population that parallels a gradient in the environment.
balanced polymorphism A type of polymorphism in which the frequencies of the coexisting forms do not change noticeably over many generations.
heterozygote advantage (HET-ur-oh-ZY-gote) A mechanism that preserves variation in eukaryotic gene pools by conferring greater reproductive success on heterozygotes over individuals homozygous for any one of the associated alleles. hibernation A physiological state that allows survival during long periods of cold temperatures and reduced food supplies, in which metabolism decreases, the heart and respiratory system slow down, and body temperature is maintained at a lower level than normal.
*hybrid vigor
frequency-dependant selection A decline in the reproductive success of a morph resulting from the morph's phenotype becoming too common  in a population; a cause of balanced polymorphism in populations.
neutral variation Genetic diversity that confers no apparent selective advantage.
Darwinian fitness A measure of the relative contribution of an individual to the gene pool of the next generation.
relative fitness The contribution of one genotype to the next generation compared to that of alternative genotypes for the same locus.
stabilizing selection Natural selection that favors intermediate variants by acting against extreme phenotypes.
directional selection Natural selection that favors individuals on one end of the phenotypic range.
diversifying selection Natural selection that favors extreme over intermediate phenotypes.
sexual dimorphism (dy-MOR-fiz-um) A special case of polymorphism based on the distinction between the secondary sex characteristics of males and females.
sexual selection Selection based on variation in secondary sex character-istics, leading to the enhancement of sexual dimorphism.
 
 

    What Is a Species?

         The biological species concept emphasizes reproductive isolation
         Prezygotic and postzygotic barriers isolate the gene pools of biological
         species
         The biological species concept does not work in all situations
         Other species concepts emphasize features and processes that identify and
         unite species members

    Modes of Speciation

         Geographical isolation can lead to the origin of species: allopatric speciation

         A new species can originate in the geographical midst of the parent
         species: sympatric speciation
         Genetic change in populations can account for speciation
         The punctuated equilibrium model has stimulated research on the tempo of
         speciation

    The Origin of Evolutionary Novelty

         Most evolutionary novelties are modified versions of older structures
         Genes that control development play a major role in evolutionary novelty
         An evolutionary trend does not mean that evolution is goal oriented

Chapter  24
macroevoloution Evolutionary change on a grand scale, encompassing the origin of novel designs, evolutionary trends, adaptive radiation, and mass extinction.
speciation (SPEE-see-AY-shun) The origin of new species in evolution.
anagenesis (AN-uh-JEN-eh-sis) A pattern of evolutionary change involving the transformation of an entire population, sometimes to a state different enough from the ancestral population to justify renaming it as a separate species; also called phyletic evolution.
*phyletic evolution
cladogenesis (KLAY-doh-GEN-eh-sis) A pattern of evolutionary change that produces biological diversity by budding one or more new species from a parent species that continues to exist; also called branching evolution.
*branching evolution
species A particular kind of organism; members possess similar anatomical characteristics and have the ability to interbreed.
biological species concept A population or group of populations whose members have the potential to interbreed.
prezygotic barrier (PREE-zy-GOT-ik) A reproductive barrier that impedes mating between species or hinders fertilization of ova if interspecificmating is attempted.
*habitat isolation
*behavioral isolation
*temporal isolation
*mechanical isolation
*gametic isolation
postzygotic barriers (POST-zy-GOT-ik) Any of several species-isolating mechanisms that prevent hybrids produced by two different species from eveloping into viable, fertile adults.
*reduced hybrid viability
reduced hybrid fertility
hybrid breakdown
morphological species concept A species defined by its anatomical features.
recognition species concept A definition of species based on mate-recognition mechanisms; assumes that reproductive adaptations of a species consist of a set of features that maximize successful mating with members of the same population; an alternative to the biological species concept.
*cohesion species concept
*ecological species concept
*evolutionary species concept
allopatric speciation (AL-oh-PAT-rik) A mode of speciation induced when the ancestral population becomes segregated by a geographical barrier.
*sympatric speciation
adaptive radiation The emergence of numerous species from a common ancestor introduced into an environment, presenting a diversity of new opportunities and problems.
polyploidy (POL-ee-ploid-ee) A chromosomal alteration in which the organism possesses more than two complete chromosome sets.
autopolyploidy (AW-toe-POL-ee-ploid) A type of polyploid species resulting from one species doubling its chromosome number to become tetraploid, which may self-fertilize or mate with other tetraploids. auxin (AWK-sins) A class of plant hormones, including indoleacetic acid (IAA), having a variety of effects, such as phototropic response through the stimulation of cell elongation, stimulation of secondary growth, and the development of leaf traces and fruit.
allopolyploid (AL-oh-POL-ee-ploid) A common type of polyploid species resulting from two different species interbreeding and combining their chromosomes.
hybrid zone A region where two related populations that diverged after becoming geographically isolated make secondary contact and interbreed here their geographical ranges overlap.
punctuacted equilibrium A theory of evolution advocating spurts of relatively rapid change followed by long periods of stasis.
*exaptation
allometric growth (AL-oh-MET-rik) The variation in the relative rates of growth of various parts of the body, which helps shape the organism.
paedomorphosis (PEE-doh-mor-FOH-sis) The retention in an adult organism of the juvenile features of its evolutionary ancestors.
heterochrony Evolutionary changes in the timing or rate of development.
homeosis Evolutionary alteration in the placement of different body parts.
species selection A theory maintaining that species living the longest and generating the greatest number of species determine the direction of major evolutionary trends.
 
 

    The Fossil Record and Geological Time

         Sedimentary rocks are the richest sources of fossils
         Paleontologists use a variety of methods to date fossils
         The fossil record is a substantial, albeit incomplete, chronicle of evolutionary
         history
         Phylogeny has a biogeograpical basis in continental drift
         The history of life is punctuated by mass extinctions followed by adaptive
         radiations of the survivors

    Phylogeny and Systematics

         Taxonomy employs a hierarchical system of classification
         The branching pattern of a phylogenetic tree represents the taxonomic
         hierarchy
         Determining monophyletic taxa is key to classifying organisms according to
         their evolutionary history
         Molecular biology provides powerful tools for systematics
         The search for fossilized DNA continues despite recent setbacks: science
         as a process

    The Science of Phylogenetic Systematics

         Phenetics increased the objectivity of systematic analysis
         Cladistic analysis uses novel homologies to define branch points on
         phylogenetic trees
         Phylogenetic systematics relies on both morphology and molecules

Chapter  25
Phylogeny (fih-LOJ-en-ee) The evolutionary history of a species or group of related species.
systematics The branch of biology that studies the diversity of life; encompasses taxonomy and is involved in reconstructing phylogenetic history.
*fossil record
geological time scale scale A time scale established by geologists that reflects a consistent sequence of historical periods, grouped into four eras: Precambrian, Paleozoic, Mesozoic, and Cenozoic.
radiometric dating A method paleontologists use for determining the ages of rocks and fossils on a scale of absolute time, based on the half-life of radioactive isotopes.
*half-life
Pangaea (pan-JEE-uh) The supercontinent formed near the end of the Paleozoic era when plate movements brought all the land masses of Earth together.
*adaptive zoneAn equilibrium state in a population when the gene pool has allele frequencies that maximize the average fitness of a population's members.
*phylogenetic trees
binomial The two-part Latinized name of a species, consisting of genus and specific epithet.
genus (JEE-nus) (plural, genera) A taxonomic category above the species level, designated by the first word of a species' binomial Latin name.
specific epithet
*family orders
*classes
phylum A taxonomic category; phyla are divided into classes.
kingdoms A taxonomic category, the second broadest after domain.
domain A taxonomic category above the kingdom level; the three domains are archaebacteria, eubacteria, and eukaryotes.
taxon (plural, taxa) The named taxonomic unit at any given level.
monophyletic (MON-oh-fy-LEH-tik) Pertaining to a taxon derived from a single ancestral species that gave rise to no species in any other taxa.
paraphyletic (PAR-uh-FY-leh-tik) Pertaining to a taxon that excludes some members that share a common ancestor with members included in the taxon.
homology Similarity in characteristics resulting from a shared ancestry.
convergent evolution The independent development of similarity between species as a result of their having similar ecological roles and selection pressures.
analogy The similarity of structure between two species that are not closely related; attributable to convergent evolution.
*DNA-DNA hybridization
*restriction maps
*DNA sequence analysis
phenetics phenetics (feh-NEH-tiks) An approach to taxonomy based entirely on measurable similarities and differences in phenotypic characters, without consideration of homology, analogy, or phylogeny.
cladistic analysis (kluh-DIS-tiks) A taxonomic approach that classifies organisms according to the order in time at which branches arise along a phylogenetic tree, without considering the degree of morphological divergence.
*clade
*outgroup
*synapomorphies
*parsimony
*phylogenetic biology