22: The Origin of Species
- Page ID
- 73851
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)- 22.1: The Nature of Species and the Biological Species Concept
- 22.1.1: Understanding Evolution
- 22.1.1.1: What is Evolution?
- 22.1.1.2: Charles Darwin and Natural Selection
- 22.1.1.3: The Galapagos Finches and Natural Selection
- 22.1.1.4: Processes and Patterns of Evolution
- 22.1.1.5: Evidence of Evolution
- 22.1.1.6: Misconceptions of Evolution
- 22.1.2: Formation of New Species
- 22.1.2.1: The Biological Species Concept
- 22.1.2.2: Reproductive Isolation
- 22.1.2.3: Speciation
- 22.1.2.4: Allopatric Speciation
- 22.1.2.5: Sympatric Speciation
- 22.1.3: Hybrid Zones and Rates of Speciation
- 22.1.3.1: Hybrid Zones
- 22.1.3.2: Varying Rates of Speciation
- 22.1.4: Evolution of Genomes
- 22.1.4.1: Genomic Similiarities between Distant Species
- 22.1.4.2: Genome Evolution
- 22.1.4.3: Whole-Genome Duplication
- 22.1.4.4: Gene Duplications and Divergence
- 22.1.4.5: Noncoding DNA
- 22.1.4.6: Variations in Size and Number of Genes
- 22.1.5: Evidence of Evolution
- 22.1.5.1: The Fossil Record as Evidence for Evolution
- 22.1.5.2: Fossil Formation
- 22.1.5.3: Gaps in the Fossil Record
- 22.1.5.4: Carbon Dating and Estimating Fossil Age
- 22.1.5.5: The Fossil Record and the Evolution of the Modern Horse
- 22.1.5.6: Homologous Structures
- 22.1.5.7: Convergent Evolution
- 22.1.5.8: Vestigial Structures
- 22.1.5.9: Biogeography and the Distribution of Species
- 22.2: Natural Selection and Reproductive Isolation
- A species is an actually or potentially interbreeding population that does not interbreed with other such populations when there is opportunity to do so.
- 22.4: The Geography of Speciation
- A species is an actually or potentially interbreeding population that does not interbreed with other such populations when there is opportunity to do so.
- 22.5: Adaptive Radiation and Biological Diversity
- Speciation occurs along two main pathways: geographic separation (allopatric speciation) and through mechanisms that occur within a shared habitat (sympatric speciation). Both pathways force reproductive isolation between populations. Sympatric speciation can occur through errors in meiosis that form gametes with extra chromosomes, called polyploidy. Autopolyploidy occurs within a single species, whereas allopolyploidy occurs because of a mating between closely related species.
- 22.7: Speciation and Extinction Through Time
- Evolutionary changes coincide with geologic changes on the earth. But consider that changes in geology (e.g., mountain formation or lowering of the sea level) cause changes in climate, and together these alter the habitats available for life. Two types of geologic change seem to have had especially dramatic effects on life: continental drift and the impact of asteroids