Biology Evolution Exam 1Questions & Answers

Evolution - ANSWERS1. theory that all organisms are related by common ancestry and due to descent with modification, changed over time 2. change in genotype/genetic make-up of a population from one generation to the next What must happen for evolution to occur by natural selection - ANSWERS1. individuals must vary/be different 2. traits must be heritable 3. differential of survival: survival and reproductive success must vary and it's not by chance Adaptive Evolution - ANSWERSindividual with highest fitness will survive and reproduce. ability to pass on genes to its offsprings How do certain phenotypes become dominant over others in a population, leave population, and emerge - ANSWERSnature favors traits that lead to high fitness, becoming more common in a population: Adaptive evolution -disadvantageous traits dont survive so cant pass on traits -- leaves population -new traits arise because of mutations (mostly deleterious or neutral) but if good, then remain in population What leads to natural selection - ANSWERSDescent with modification: Both parents pass down traits but the traits have slight modifications. because of this, evolution changes a population over time: there are the phenotypes from the ancestors and the new traits that have developed from advantageous mutations. Evidence for evolution/descent with modification - ANSWERS1. Biogeography 2.Homology 3. Molecular Structure 4. Vestigial Traits Biogeography - ANSWERSshows how organisms differ over geographic space ex. Birds on Galapagos islands: all look physically similar, but vary somewhat to fit niche. Shows that came from common ancestor but changed over time Homology - ANSWERSsimilar structures or genes because of common ancestor but acquired differences through evolution ex. bats, humans, and dogs have same bone structure but used for diff. functions ex. embryo of chicken, snake, human, and cat look alike during first stage Molecular Structure - ANSWERSall organisms have same genetic code (because of common ancestor) with little difference. --differences exist due to mutations that are not deleterious and therefore still allow the organism to function normally. ex. DNA of mouse and human. Evolution proved because of some change in gene sequence even though majority are parallel. Vestigial Traits - ANSWERSphenotypes found in both modern organism and ancestor, but serves no purpose for modern organism. Natural selection does not act to eliminate it because not harmful to organism. Evidence for evolution because significant for ancestor, but due to change over time, serves no function to us ex. Humans have sequence for GLO pseudogene to synthesize vitamin C, but it does not work. Evidence for species changing over time - ANSWERS1.Fossils 2. Law of succession 3. Fossil series/transitional forms 4. Direct Observation Fossils - ANSWERSfossils of extinct organisms look similar to modern day organisms -----species are related but evolution occurs so that some traits are not shared with modern organism Law of succession - ANSWERSfossils in a particular area share similarities with organisms in that area Fossil series/Transitional forms - ANSWERSFossil records that show anatomical changes in a specific organism ex. whale: sea creature -- land animal -- sea creature. shows that species change over time Direct observation - ANSWERSObserving traits of organisms directly to note changes ex. Drought in Galapagos islands left large seeds, so through evolutionary changes, only birds with big and wide beaks had high fitness. Avg. beak size changed overall James Ussher - ANSWERSgenesis occurred Sunday Oct 23rd 4004 B.C.; humans have prehistory Galileo, Copernicus, Newton - ANSWERSEarth is part of larger universe Thomas Hobbes - ANSWERSHumans are diff now than before thus earth has changed. Fossils = living things from before The Englightenment - ANSWERSintellectual resistance against the Church Carolus Linnaeus - ANSWERS"Father of Taxonomy" --believed that species couldn't change --ordered species through relativism Lamarck - ANSWERS1. species change over time; never go extinct 2. species give rise to new species (Darwin agrees with) 3. Characteristics are inherited 4. Complex organisms evolve longer Malthus - ANSWERS1. Pop growing, but food isnt, so struggle for existence and competition for food 2. Wealthy will outcompete the poor Lyell - ANSWERSUniformitarianism -- Earth formed by same processes that occur today 1. earth has no begging or end 2. change happens slowly Basis of evolution - ANSWERS1. Natural Selection 2. Gene flow 3. Genetic drift 4. Mutation Gene flow - ANSWERStransfer of alleles from one pop to another via immigration; counteracts genetic drift ex. pollen being blown, people moving to diff countries, snakes moving to diff areas and traits become common Reduces genetic variation Genetic drift - ANSWERSchange in allele frequency due to random sampling; if an offspring survives and reproduces more than another organism, then those genes will be prevalent in the next generation by chance because of reproductive success reduces genetic variation Mutation - ANSWERSrandom, rare, and deleterious. -increase amount of variations in pop, allowing genetic variation to exist, allowing natural selection to occur Natural selection acts on ____; _____ evovle WHY? - ANSWERSindividuals; populations N.s. determines who survives and reproduces, and who dies can you have natural selection without evolution? - ANSWERSYes; if heritability doesn't occur Which evidence convinced Darwin about N.S. by adaptive evolution - ANSWERSArtificial Selection Artificial Selection - ANSWERShumans breed organisms which can change the phenotypes over generations. Proof for evolution by natural selection, because if humans can pick desired traits, breed them, and reproduce offspring with the traits then nature can as well. Rapid Evolution - ANSWERSaffects human health and welfare: 1. Antibiotic Resistance 2. Pesticide Resistance 3. Herbicide Resistance Antibiotic Resistance - ANSWERSbacteria becomes resistance to antibiotics when environment is filled with antibiotics Pesticide Resistance - ANSWERSPesticides aren't working; need more to have same effect Herbicide Resistance - ANSWERSweeds become more resistant to herbicide insects become resistant after generating crops with seeds What is adaptation - ANSWERSany heritable trait that helps organism survive Comparative Method - ANSWERSCompare different degrees of relativeness among groups to test adaptation ex. males of some species have larger testes than others because testes size is large when group size is large Directional Selection - ANSWERSone extreme is favored; pushes avg. to one end ex. giraffes with longer necks have advantage Stabalizing Selection - ANSWERSMiddle (avg) is favored ex. birth weight of humans Disruptive Selection - ANSWERSBoth extremes are favored ex. black, gray, and white rabbits Black and white rabbits can camouflage easily but gray cant and so will die out Frequency dependent Selection - ANSWERSthe best phenotype depends on how common the trait is in the population. Fitness depends on its frequency; when one is high, the other is low