PPT-Speciation Prezygotic isolation

Temporal crickets mature at different times Prezygotic isolation Habitat land vs water garter snakes Prezygotic isolation Behavioral firefly mating Prezygotic isolation Gametic. 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. Results of evolution. New species (speciation). Causes of evolution. Barriers between same species (gene pools). Geographical isolation -> leads to . allopatric. speciation. Temporal isolation -> leads to sympatric speciation. Macroevolution is essentially the formation of new species (speciation) and accompanying events. . Reproductive isolation can occur in a variety of ways. Reproductive isolation is the key to cladogenic speciation. SC B-5.4: Explain how genetic variability and environmental factors lead to biological evolution.. Speciation:. formation of a new species. Species. : group of similar organisms that can successfully breed & their offspring are fertile. Brian O. ’. Meara. EEB464 Fall . 2015. http://www.youtube.com/watch?v=lopTMhAbXoI. Initiation of speciation. Maintenance of current species. Prezygotic. Postzygotic. Zygote image © Laboratoire de Biologie de la Reproduction; Lausanne, image downloaded from . Chapter 18. “When you realize how perfect everything is, you will tilt your head back and laugh at the sky”. -. Budda. What is a Species?. Biological species concept. : species are groups of actually or potentially interbreeding natural populations which are . Concept 22.2: Speciation can take place with or without geographic separation. Speciation can occur in two ways. Allopatric speciation. Sympatric speciation. Allopatric (. “. Other Country. ”. ) Speciation. Meara. EEB464 Fall . 2017. http://www.youtube.com/watch?v=lopTMhAbXoI. Learning objectives. Understand factors that can lead to speciation. Consider the geography of speciation. Describe approaches to . 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. . Finish vocabulary cards from yesterday. VOCABULARY QUIZ NEXT MONDAY!. TEST NEXT THURSDAY! -4 MORE DAYS!. Types of Speciation, Evolution & Isolation. Thursday. January 22nd . Currently there are . Reproductive . isolating. mechanisms. Prezygotic. isolating mechanisms. Geographic isolation. Ecological isolation. Behavioral isolation. Temporal isolation. Mechanical isolation. Prevention of gamete fusion. 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!). 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. 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 .