PPT-Recombination rate influences adaptation and speciation: Studies in the

Drosophila pseudoobscura species group Mohamed A F Noor Duke University EVOLUTION Two fundamental processes Change within lineages adaptation important Form new lineages speciation important. Vaccinium. . macrocarpon. ). Brandon . Schlautman. What is a species?. Domain- . Eukarya. Kingdom- Plantae. Phylum- . Magnoliophyta. Class- . Magnoliopsida. Order- . Ericales. Family- . Ericaceae. Is a member of the . 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. Summary of assumptions so far. We have covered the role of chance (parent choice), demography (population size) and mutation, in shaping genetic diversity. . Neutral Wright-Fisher . models. Parents are always chosen at random. This means no new mutations affect reproductive success of parents, i.e. . 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. 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.. 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 . Pairs of allelic genes may exchange chromosomal locations( genetic elements can move, both between chromosomes and within them.) by a process known as genetic recombination.. Homologous recombination . (Unit 10, species concept. Sympatric speciation . Sympatric speciation, (from the Greek ‘same place’) involves the splitting of an ancestral species into two or more reproductively isolated groups without geographical isolation of those groups.. Science. Lesson 8: challenge answer. Investigate and make note of other species that have evolved due to parapatric speciation. . Typically seen in species of fish.. Learning intention. To know what sympatric speciation is and how it occurs. . 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. Avneet. Singh, Steven . Ancheta. , Giovanni . Corralhejo. , Katie . Laackmann. Definition. Origin of new species in evolution. There are two general modes of speciation. Allopatric. speciation. Sympatric speciation.