PPT-Evolution of Populations II

Genetic Drift A random change in allele frequency certain individuals leave more descendants than others just by chance Because of a random occurrence the brown allele has become even more common . A. Darwin’s . Ideas revisited. - it . was more than 50 years after Darwin started to develop . his theory . of evolution before biologists could determine . how evolution . takes place. - about . 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. . Chapter 42. Chapter 42 Populations. Key Concepts. 42.1 Populations Are Patchy in Space and Dynamic over Time. 42.2 Births Increase and Deaths Decrease Population Size. 42.3 Life Histories Determine Population Growth . 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?. Contribution to Session One, Radical Statistics Conference, 23. rd. February, 2013, Priory Street Centre, YORK. Roy Carr-Hill. Household Surveys. Omitted from Sampling Frames by Design. Homeless populations. 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. 30 Minute Inquiry Activity. Research one of the following types of Evolutionary Evidence:. Fossil . Record. Vestigial . Structures. Homologous . Structures. Comparative . DNA. Note . the following about your type of evidence:. 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. What do we use in order to determine evolutionary relationships?. Fossil Record. Anatomical Evidence. Molecular Evidence. Embryological Evidence. Evidence for Evolution. Fossil Record. Evidence for 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? . Individuals do not evolve, populations do…Darwin. Lynn English High School Science. Biology/Ms. Mezzetti. Population Genetics and Speciation. Genetic Equilibrium. Genetic Variation. Population genetics is the study of evolution from a genetic point of view. Vestigial Structures. DNA & The Genetic Code. Fossil Record. Strata & Superposition. Relative Age vs. Absolute Age. Fossil Record. Per the theory - You would expect older rock to contain mostly organisms that are less complex and less like current (living) organisms.