PPT-Species and Mechanisms of Speciation

I Species Definitions Species represent the boundary for the spread of alleles and define the unit in which the modes of evolution operate Biological Species Concept Individuals belong to the same species if they can interbreed with each other. What is a Species?. Speciation. – the origin of new species. The . biological species concept. defines a species as a population or group of populations whose members have the potential to interbreed with one another in nature to produce viable, fertile offspring, but who cannot produce viable, fertile offspring with members of other species. The rise and fall of biodiversity. Four major . mass extinctions . of marine organisms:. End of Silurian Devonian, Permian, and Cretaceous). Rise in diversity during Cambrian, Silurian, Cretaceous, and Paleogene. EVOLUTION #1 (Group 3). Strawberry Frogs Forever. Participants: Lin Xiang. Ingo . Schlupp. Tiffany Roberts. Anne . Grippo. Jerry Farris. Facilitators: Brooke . Evolution. Speciation Basics. Individuals of different species cannot . interbreed. under natural conditions . Described as being . reproductively isolated . from one another. Populations of different species do . The rise and fall of biodiversity. Four major mass extinctions of marine organisms:. End of Silurian Devonian, Permian, and Cretaceous). Rise in diversity during Cambrian, Silurian, Cretaceous, and Paleogene. Species. == “kind” or “type” in Latin. Typological . (morphological) species. . == a group of organisms that share certain characteristics which are different than other groups—usually differences in anatomy. . Species. – group of organisms that interbreed and produce fertile offspring. Subspecies. – groups that are on the way to being separate species; have started being genetically different. Individuals in the same species share a common gene pool. Temporal – crickets mature at different times. Prezygotic. isolation. Habitat – land vs. water garter snakes. Prezygotic. isolation. Behavioral – firefly mating. Prezygotic. isolation. Gametic. Sympatric Speciation. Sympatric Speciation occurs . without. geographic isolation, thus it occurs at a local level. . There is something within the environment that keeps a single species separated into two or more distinct groups.. Gene Pool. All the alleles present in the reproducing members of a population at a given time.. The gene pool is constantly changing. Mutations add new alleles to the population. Immigration also adds new alleles; changes the allele frequency. What defines a species?. Species: a group of organisms that can . interbreed. and produce . fertile. offspring. “Biological Species Concept” . Human species?. Homo sapiens – “wise man” (large brains!). Populations must become isolated. Reproductive isolation is key!. Once isolated, populations will evolve independently (different factors affecting each). Two types of speciation. allopatric. geographic separation. In evolutionary terms a . species . is a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring; they do not breed successfully with other . After reading this module you should be able to. Explain . the processes of allopatric and sympatric speciation.. U. nderstand . the factors that affect the pace of . evolution.. Speciation can be allopatric or sympatric.