PPT-Module 16 Speciation and the Pace of Evolution

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. The . formation of a new . species. 15.3 Speciation. What is a species?. A group of organisms with similar characteristics capable of producing fertile . offspring. Members of a . species. . share. the . Patterns of Evolution. Credits: 4. External. ! Before we begin…. From the . examination specifications…. Giraffe Evolution?. Revision. 12 bio stuff…. Stuff u should know from Year 12. Natural Selection. 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. 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. 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 . 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 . 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!). 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. Outcomes of Evolution Selection acts on Variation Directional Disruptive Stabilizing Genetic variation Directional Selection Favors one of the extreme variations of a trait 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 . Chapter 11 Biology Textbook. KEY CONCEPT . Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.. . Hardy-Weinberg equilibrium describes populations that are not evolving. .