Evolutionary Bio Test 2 Review
Evolutionary Bio Test 2 Review 12050 - BIOL 3350 - 001
Popular in Evolutionary Biology
Popular in Biological Sciences
80887 - BIOL 3150 - 001
verified elite notetaker
This 7 page Study Guide was uploaded by Adam Rodenberg on Friday February 26, 2016. The Study Guide belongs to 12050 - BIOL 3350 - 001 at Clemson University taught by Dr. Michael Sears in Spring 2016. Since its upload, it has received 88 views. For similar materials see Evolutionary Biology in Biological Sciences at Clemson University.
Reviews for Evolutionary Bio Test 2 Review
Please tell me you're going to be posting these awesome notes every week..
-Mrs. Elmira Spinka
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 02/26/16
Evolutionary Bio Test 2 Review Textbook Vocab. Chapters 58 Ch. 5 Genetic variation diversity in gene frequencies Environmental variation genetic variation resulting from environmental influences Genotypebyenvironment when two different genotypes respond to environmental variation in different ways Genome the corpus of genetic instructions carried by an individual Alleles different versions of a gene Genotype the combination of alleles an individual carries Phenotype the suite of an individual exhibits Inducible defense growth of armor in response to phantom midge kairomone Expression production of proteins Epigenetic marks Features not directly governed by the genetic code Phenotypic plasticitya characteristic of organisms who develop different phenotypes in different environments Mutations changes in the genome Premutations alterations to DNA due to chemical degradation and replication errors must evade correction to become persistent mutations Point mutation the substitution of one base for another (the smallest possible mutation) Transition substitution of a purine for a purine or a pyramidine for a pyramidine Transversion substitution of a purine for a pyramidine or vice versa Synonymous(silent) mutation a mutation that leaves the protein unaltered Nonsynonymous(replacement) substitution a mutation that changes the amino acid specified by a codon Nonsense mutation a mutation that introduces a premature stop codon Introns noncoding sequences Exons coding sequences Indels point mutations, insertions, and deletions Gene duplications unequal crossing over, retroposition, or retroduplication Pseudogenes a nonfunctional gene that lacks regulatory sequences thata cause it to be transcribed Paralogous genes that are located in a genome and later diverge in function Orthologous genes derived from a common ancestral sequence and separated by a speciation event Inversions a chromosome rearrangement in which a segment of a chromosome is reversed end to end Linkage the tendency for alleles of different alleles of different genes to assort together at meiosis Polymorphic chromosomes with and without specific inversions exist Cline regular change in the frequency of an allele or an inversion over a geographic area Polyploid organisms with more than two chromosome sets Mutation accumulation the evolutionary effect of adverse events declines following the age at which an organism is initially capable of reproduction Ch. 6 Population genetics integrates evolution by natural selection with Mendelian genetics Population a group of interbreeding animals and their offspring Gene pool all the eggs and sperm produced by all the adults in the population, dumped into a (figurative) barrel Genetic drift the fact that blind luck can cause a population to evolve unpredictably Selection what happens when individuals with particular phenotypes survive to sexual maturity to produce offspring than those with other phenotypes Heterozygote superiority/Overdominance a hypothesis in which heterozygotes have higher fitness than either homozygote Underdominance the selection against the mean of a population distribution, causing disruptive selection and divergent genotypes Frequencydependent selection when selection favors one character until it becomes too common, then switches to favor another character Mutationselection balance when the rate at which copies of deleterious allele are being eliminated by selection is equal to the rate at which new copies are being created by mutation, the frequency of the allele is at equilibrium Ch. 7 Sampling error when the statistical characteristics of a population are estimated from a subset, or sample, of that population Random genetic drift sampling error in the production of zygotes from a gene pool Founder effect the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population Heterozygosity frequency of heterozygotes in a population Fixation index (F ST a measure of population differentiation due to genetic structure Effective population size the size of an ideal theoretical population that would lose heterozygosity at the same rate as an actual population of interest Substitution the fixation of a new allele, with or without additional mutational change Genetic drift the change in the frequency of a gene variant in a population due to random sampling of organisms Neutral theory formulated by Kimura, saying that effectively neutral mutations that rise to fixation by drift vastly outnumber beneficial mutations that rise to fixation by natural selection Silent site (synonymous) mutations DNA sequence changes that do not result in an amino acid change Replacement (nonsynonymous) mutations sequence changes that do result in an amino acid change Negative / purifying selection natural selection that eliminates deleterious alterations before they become common Positive selection selection for beneficial mutations that increases their frequencies Polymorphism a locus at which individuals in a population carry different alleles Codon bias differences in the frequency of occurrence of synonymous codons in coding DNA Hitchhiking / selective sweep the reduction or elimination of variation among the nucleotides in neighboring DNA of a mutation as the result of recent and strong positive natural selection Background selection results from negative selection against deleterious mutations Coalescence merging of genealogical lineages as we trace allele copies backward in time Gene tree / gene genealogy the use of DNA testing in combination with traditional genealogy and traditional genealogical and historical records to infer relationships between individuals Inbreeding mating among genetic relatives Coefficient of inbreeding (F) the probability that the two alleles in an individual are identical by descent Inbreeding depression the reduced biological fitness in a given population as a result of inbreeding Ch. 8 Haplotype multilocus genotype of a chromosome or gamete Linkage equilibrium two loci in a population Linkage disequilibrium when there is a nonrandom association btwn a chromosomes genotype at one locus and its genotype at the other locus Genetic recombination the creations of new combinations of alleles during sexual reproduction Extended haplotype homozygosity (EHH) the probability that two randomly chosen chromosomes carrying the core haplotype of interest are identical by descent (as assayed by homozygosity at all SNPs) for the entire interval from the core region to a distance Parthenogenesis a mode of reproduction in which offspring develop from undeveloped eggs Genetic load the burden imposed by the accumulating mutations when an asexual population’s average fitness is decreasing over time Major Points About the Test from Dr. Sears 2 2 2 Calculating allele frequencies HardyWeinberg principle (p + q) = p + 2pq + q = 1 HW conclusion1 the allele frequencies in a population will not change, generation after generation HW conclusion 2 If the allele frequencies in a population are given by p and q, the genotype frequencies will be given by p2, 2pq, and q2. Chi squared test x⌃2= E(observed expected)^2/(expected) Expected for AA = (P^2)N Expected for Aa= 2PQN Expected for aa= (Q^2)N N=total Know example of Medea, Know example of CF and typhoid in humans, will go over in review session Effects of genetic drift 1. Because the fluctuations in allele frequency from one generation to the next are caused by random sampling error, every population follows a unique evolutionary path. 2. Genetic drift has a more rapid and dramatic effect on allele frequencies in small populations than in large populations. 3. Given sufficient time, genetic drift can produce substantial changes in allele frequencies even in populations that are fairly large. Go over selection, selection/mutation balance, drift, Know the math!, be able to put things in and manipulate and come up with an answer, go over the quizzes Selection vs natural processes (1) Deleterious alleles appear and are eliminated by selection; (2) Neutral mutations appear and are fixed or lost by chance; and (3) Advantageous alleles appear and are swept to fixation by selection. Not planning on having equations provided on the exam Know HardyWeinberg like the back of your hand Know Linkage disequilibrium Evolution at 2 loci 2 physically linked loci (next to each other on the same chromosome) Populations can have identical allele frequencies but different chromosome frequencies ( one in HWE but the other might not) In order to calculate if this pop is in eq. we calculate the freq. on chromosomes carrying a and A allele. If in equilibrium the frequencies should be equal. The coefficient of linkage disequilibrium, symbolized by D, is defined as gABgab−gAbgaB <typo in book gAB = ps, gAb = pt, gaB = qs, and gab = qt D =psqt−ptqs = 0 D ranges between 0.25 and 0.25 ^genotype frequencies of the gametes Two loci in a population are in linkage equilibrium when the genotype of a chromosome at one locus is independent of its genotype at the other locus. Two loci are in linkage disequilibrium when there is anonrandom association between a chromosome's genotype at one locus and its genotype at the other locus. Freq of A 8 freq of B should give you the genotype freq of AB r = recombination rate d = disequilibrium while in disequilibrium, chromosome frequencies move closer to equilibrium with each generation C. elegans example asexual individuals grow unfit over time higher mutation rate selected for more frequent outcrossing, and more males Don’t need to read chapter 9, too much info on the test, going over it 2/25/16 anyway? Disequilibrium vs HWE Look at example in book about Crohn’s disease 3 things that push a population into linkage disequilibrium genetic drift, ____, _____ Know how to calculate the b statistic Closer to 0, the less disequilibrium Know how to calculate d, allele frequencies, ____, Math problems will be posted on mindmeister Know all of the equationssome might be on the test, be prepared for none, won’t be labeled, might need to be rearranged Calculate fitness, avg fitness, chi square, interpret them, Know everything on the review link under week 6 Go through case studies in the textbook Sex can save you from mullers ratchet says that the deleterious mutations that accumulate from asexual reproduction are likely to be at least balanced out in the population When would it be advantageous to have more alleles in a population? more stressful environment
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'