BIOL 112 Johnson Exam 1 Study Guide Chapter 22 What is the definition of Evolution What are some common misconceptions about evolution Describe Darwin s Background Darwin s Background o HMS Beagle 1831 1836 Darwin paid specific attention to geographical distribution and adaptations of animals across the globe o Studied local geography o Principle of Uniformitarianism Lyell convinced Darwin that the earth is millions of years old o Developed his theory in 1844 but went public in 1858 o Some ideas were shared by others for example Darwin and Alfred Wallace published their original works together o On The Origin Of Species was published in 1859 o Knew Lemarckian evolution was wrong but agreed that adaptations are key to evolution Darwin s Theory Of Evolution o All present life is related through descent with modification with a common ancestor in the past o Now referred to as evolution o Natural Selection The mechanism for evolution Darwin s Observations o 1 All creatures seem to create more offspring that the environment can support Think Malthus o Most populations are relatively stable o Based off agrees with Malthus observations that the potential for human populations is exponential and resources of the modern world cannot sustain o 2 There is a heritable individual variation within a species Individuals with a trait that helps them survive and reproduce will have more offspring than other less fit individuals OR There is unequal reproductive success among individuals of a population Heritable favorable traits or adaptations accumulate over time and may ultimately lead to a new species based on different environments and natural consequences Unfavorable variations are lost over time Natural selection results in different adaptations in different environments Describe the Evidence Used to Support Darwin s Theory Direct Observation of Natural Selection o Ex Soap berry Bugs and Antibiotic Resistance Fossil Record o Older rocks lay below newer rocks o Extinct Species o Transition Forms Homology o Homologous Structures o Vestigial Structures o Developmental Homologies o Molecular and Cellular Homologies Convergence o Analogous Structures o Natural Selection will select similar adaptations across different environments and lineages Biogeography Chapter 23 Describe the relationship between Mendel s Genetics and Darwin s Evolutionary theory Understand the basis for the biological definition of a Species and a Population What level or organization does Natural Selection act on Evolution To Prove Natural Selection o Is a trait heritable o Is the trait an advantage over other individuals Genetic Variation Be familiar with the following topics these will not be tested discretely Discrete Variation o Genotype determines the phenotype o A single gene locus with 2 or more alleles o Includes co dominance complete incomplete dominance Quantitative Variation o Phenotype is produced via additive effects of two or more genes o Generally involved two different chromosomes or loci Define Gene Pool Microevolution Define and explain the following terms associated with Hardy Weinberg Genotypic Frequency o AA Aa aa o Typically seen by the phenotype Allelic Frequency o A and a List the Hardy Weinberg Requirements Assumptions 5 Explain the process of Genetic drift name and describe the two key mechanisms and explain how both affect variation and diversity within a population Explain the process of Gene Flow and understand the results Forms of Natural Selection Be able to give an example of each and understand what happens to the average phenotype o Directional Selection o Disruptive Selection o Stabilizing Selection o Sexual Selection How does sexual selection lead to sexual dimorphism How is genetic variation maintained in the population Through Diploidy o What is heterozygote advantage o How are recessive alleles maintain in the population Through Disruptive Selection o What happens if over time disruptive selection continues Through Frequency Dependent Selection o How do allelic frequencies act in this case Explain the limits of Natural Selection Chapter 24 What are reproductive barriers and how do they contribute to maintaining biological species Pre Zygotic Barriers Prevent fertilization and mating from occurring pre baby o Habitat ecological isolation o Temporal isolation o Behavioral isolation o Mechanical isolation o Gametic isolation Post Zygotic Barriers act after the zygote is formed but not necessarily after birth of hybrid o Reduced Hybrid Viability o Reduced Hybrid Fertility o Hybrid Breakdown What are some problems with the biological species concept o Fossils Asexual species sometimes hybrids happen How do new species form Speciation increases the diversity of life What are the requirements for speciation to occur o One population must becomes genetically isolated o It must genetically diverge from the other population o Biological reproductive barriers must arise o Speciation may occur with or without geographic isolation Define Allopatric Speciation paying close attention to the two mechanism discusses in class and specifically how it leads to the creation of new species Allopatry a physical barrier forms and separates members of the same population Usually results in some form of evolutionary change often creating new species o What happens if reproductive barriers do not arise from the separation o What is the evidence for allopatric speciation EX mosquitofish body shape influences mate choice EX fruit flies adapted to different foods and diverged enough to prefer similarly adapted mates EX Sister species of shrimp live across the panama land bridge Define Hybrid Zones the three different types and what happens to the prezygotic barriers in each case o Reinforcement o Fusion o Stability What is sympatric speciation Why is it so much more common in plants Isolation by Habitat Isolated behaviorally by sexual selection Isolation by polyploidy o What is polyploidy o Define autpolyploidy Polyploidy hybrids of two different species Sympatric speciation in animals most likely occurs through different kinds of habitat isolation where no real physical barriers are present Chapter 25 Define Macroevolution How is it different from other types of evolution discussed in class Explain lineage direction in terms of Macroevolution Each lineage group began from one species Subject to various amounts of microevolution followed by more speciation and or extinction events What is Adaptive Radiation How