Speciation Time Frames

Ugandan cichlids = Speciation event interval of 4,000 years Some beetles = Speciation event interval of 40 million years Japanese land snails = Mechanical barrier to reproduction due to shell spirals Monkey flower Mimulus = Examined by Douglas Schemske and his colleagues

Gene flow = The process that must be interrupted for speciation to begin Genetic divergence = The process that reverses the speciation process Reproductive isolation = The result of genetic divergence between populations Mass extinction = An event that can affect the time for Earth's life to recover

Japanese land snails = Example of a single gene controlling speciation Monkey flower Mimulus = Example of plant genetic manipulation Ugandan cichlids = Example of polyploid speciation in animals Some beetles = Example of mechanisms of polyploidization

<p>Douglas Schemske and his colleagues = Examining the monkey flower Mimulus Unknown = Researching the polyploid species in agriculture</p> Signup and view all the answers

<p>500,000 years = The minimum time required for speciation to occur 6.5 million years = The average time between speciation events 4,000 years = The time taken for speciation to occur in Ugandan cichlids 40 million years = The maximum time taken for speciation to occur in some beetles</p> Signup and view all the answers

<p>Allopolyploidy = A mechanism of polyploidization in plants Polyploid speciation = A type of speciation occurring in animals Genetic divergence = A process that occurs after gene flow is interrupted Mass extinction = An event that affects the rate of speciation</p> Signup and view all the answers

<p>Microevolution = The study of adaptive change in a population Macroevolution = The study of evolutionary changes above the species level Speciation = The process of genetic change within a population Species = A group of organisms that can interbreed</p> Signup and view all the answers

<p>Charles Darwin = Described the process of macroevolution Ernst Mayr = Proposed the biological species concept</p> Signup and view all the answers

<p>Allele frequencies = The study of changes in a population over time Microevolutionary mechanisms = Include mutation, natural selection, genetic drift, and gene flow Macroevolution = The study of changes in allele frequencies within a population Speciation = The process of adaptive change in a population</p> Signup and view all the answers

<p>Biological species concept = Emphasizes reproductive isolation Microevolution = Deals with questions such as the appearance of evolutionary novelties Macroevolution = Studies adaptive change in a population</p> Signup and view all the answers

<p>Evolutionary novelties = The appearance of new characteristics, such as feathers and flight in birds Speciation = The process of evolutionary changes above the species level Genetic drift = The process of genetic change within a population</p> Signup and view all the answers

<p>Reproductive isolation = A key concept in the biological species concept Microevolution = The study of evolutionary changes above the species level Macroevolution = The process of speciation</p> Signup and view all the answers

<p>Niles Eldredge = Reinforcement in hybrid zones Stephen Jay Gould = Description of the pattern of apparent stasis punctuated by sudden change Charles Darwin = Theory of Natural Selection Jean-Baptiste Lamarck = Theory of Inheritance of Acquired Characteristics</p> Signup and view all the answers

<p>Punctuated equilibrium = Gradual change over long periods of time Reinforcement = Selection for increased reproductive isolation Allopolyploidy = Mechanism of polyploidization Hybrid zone = Barrier to reproduction between closely related species</p> Signup and view all the answers

<p>Rapid speciation = Result of changes in few genes Slow speciation = Result of changes in many genes Punctuated equilibrium = Gradual change over long periods of time Allopolyploidy = Result of changes in few genes</p> Signup and view all the answers

<p>Fossil record = Provides information about the timing of speciation in specific taxa Molecular data = Provides information about the number of genes that change during speciation Hybrid zones = Provides information about the mechanisms of polyploidization Biological experiments = Provides information about the rate of speciation</p> Signup and view all the answers

<p>Reinforcement = Selection against hybrids in the hybrid zone Gene flow = Barrier to reproduction between closely related species Hybrid zone = Area where two species interbreed Allopolyploidy = Mechanism of polyploidization in hybrid zones</p> Signup and view all the answers

<p>How long does it take a new species to form? = Question about the rate of speciation How many genes change during speciation? = Question about the mechanisms of speciation What are the barriers to reproduction between closely related species? = Question about the mechanisms of speciation What are the characteristics of hybrid zones? = Question about the rate of speciation</p> Signup and view all the answers