PPT-23 The Evolution of Populations

The Smallest Unit of Evolution A common misconception is that organisms evolve during their lifetimes Natural selection acts on individuals but only populations evolve Consider for example a population of medium ground finches on Daphne Major Island. 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 . SPECIATION. : . the development of a new species. Sometimes the variation among organisms is too great; . eventually they could become separate species. GEOGRAPHIC ISOLATION. :. two populations are separated by geographic barriers such as rivers, mountains, bodies of water, etc. . H.-W. Rix IMPRS Galaxies Course March 11, 2011. Goal:. Determine . n. *. (M. *. ,. t. age. ,[Fe. /H],. R. ). . for a population of galaxies. How many stars of what mass and metallicity . formed when and where in galaxies?. metallicity. gradients . in disk galaxies from . integrated stellar populations. Patricia Sánchez-. Blázquez. . And the CALIFA collaboration. Evolution of the . metallicity. gradients in cosmological simulations. There is overwhelming evidence for the evolution of life on Earth. . Evolution in summary. Evolution occurs when heritable characteristics of a species change. . Evolution at its most fundamental level simply describes a . EVOLUTION OF POPULATIONS. Genes and Variation 16–1. Section 16-1. . A _______________ is a . group of individuals of the same species that can interbreed and produce fertile offspring.. POPULATION. Last week we talked about. …. The universe had a beginning. God must be the creator of the universe. 3 views Christians can faithfully hold: Old-Earth Creationism, Young-Earth Creationism, Theistic Evolution. Question? . Is the unit of evolution the . individual. or the . population?. Answer = while evolution effects individuals, it can only be tracked through time by looking at populations. So what do we study? . Early atmosphere, evidence, natural selection and disease agents influence natural selection. . Introduction . Evolution “ simple” definition: change over time. Evolution helps us to understand the history of life.. Chapter 22 – Descent with Modification. The Era of Evolutionary Biology. On November 24, 1859, . Charles Darwin. . published his hypothesis in . On the Origin of Species by Means of Natural Selection. Change in . allele frequencies . in a population over generations. Microevolution. Speciation. = origin of species. Microevolution. : changes . in allele frequencies within . a single gene pool. Macroevolution. of . the Red . Queen. CfE. . Advanced Higher Biology. Unit . 2: . Organisms and Evolution. SQA mandatory key information. A change in the traits of one species acts as a selection pressure on the other species. . 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. What is . Biodiversity. ?. It is the variety of earth’s species, the genes they contain, the ecosystems in which they live, and the ecosystems processes such as energy flow and nutrient cycling that sustain all life..