BIO 120 FINAL STUDY GUIDE 2020 - University of Toronto | BIO120 FINAL STUDY GUIDE 2020

UTSG BIO120H1 FINAL EXAM STUDY GUIDE ○ Three requirments ○ Variation ○ Heredity ○ Selection ○ ***did not understand genetics and mech. Of inheritance • Darwin's theory The central unifying concept of bio, ...

UTSG BIO120H1 FINAL EXAM STUDY GUIDE ○ Three requirments ○ Variation ○ Heredity ○ Selection ○ ***did not understand genetics and mech. Of inheritance • Darwin's theory The central unifying concept of bio, influential concept of western thought ○ ○ Primary unit = populations HOW- determine the physiological or genetic mech. Responsible for a trait § § WHY- ecological & adaptive sig. of a trait ○ Questions • Theory of evolution Micro-evolu. Mechs. ( process orientated and experimental) ¯oevolution = evolu. History (pattern based and non-experimental) • § Observe, theoretical, comparative, experimental ○ Approaches § Organisms on earth have changed through time § The changes are gradual not instantaneous Lineages split or branch by speciation resulting n the generation of biodiversity § § All species have common ancestors Most evolutionary change results rom natural selection - the only process responsible for the evolution of biodiversity and adaptation § ○ Assumptions • Approaches and assumptions in evolutionary biology ○ Product of evolu. ○ Process: nat sel. ○ Biodiv- the variety of life on earth/#&kinds of orgs in an area • Biodiversity and adaptation Topics and Concepts Lecture 1 Intro to evolutionary biology Friday, October 7, 2016 10:22 PM find more resources at oneclass.com find more resources at oneclass.com○ § State: noun: trait § Process: verb: process leading to origin of trait ○ Adaptation- state or process § Invasive aq. Plant § Clonal and sexual reproduction Proff Barrrett Lab: darwin missing form of water hyacinth, patterns of genetic div. ○ colonization by a few individuals that start a new population with only limited diversity compared with the source population ○ • Founder events ○ Water hyacinth cloning = most reproduction • Clonal propagation ○ Hover or perch during nectar feeding • Bird pollination ○ Is an adaptation ○ In Rat Tail plant ○ Feeding strategy ○ Efficient cross-pollination and high seed set ○ Remove = reduce fertility and outcrossing • Perch function • Reproductive success- example is the bird perch of rat tail -fitness= performance of transferring genes -hard to look at an organism and try to understand it without knowing its evolutionary history • find more resources at oneclass.com find more resources at oneclass.comWhat is the concept than the individual species You don’t have to learn the species scientif names, scientific dates Seedlings that moved farther would survive b/c 1. competing with tree you are underneath so survival rate decreases that tree also has pests so more likely to get infected by pathogens from tree that they are under 2. Adaptive benefits of dispersal Mothers usually send offspring out b/c they don’t want to compete with them Thorns Production of belshen body etc from acacia tree Benefit of having ants on plants When you do remove ant the tree gets covered with beetles (BIOTIC DEFENSE) Bare areas in forest à why? Any plant that colonizes and competes with host that is housing these ants is a competitor The original plant wont grow as much so ant wont colonize to their potential So the ants kill the competitor plants coming into forbic acid like herbicide Ants eradicate the competitor Abiotic and biotic factors = features of environment Environment is driving force of evolution Abiotic = physical factors of environment ex. Temp, fire, rainfall, frost, wind Biotic = other organisms that are affecting the organism we are interested in ex. Animals/plants/pathogens/pollinators Tutorial 1 Monday, September 19, 2016 10:06 PM find more resources at oneclass.com find more resources at oneclass.comin ex. Animals/plants/pathogens/pollinators When bioic factors interact with the specific organism = coevolution Darwins epiphany: 1. Read 2 books = Charles = gradualism/world is changing/time = thomas’s book = carrying capacity = pop will grow exponentially and then flattens out = asymptote (density dependent mortality) 2. Darwin’s concept of a species couldn’t figure out which species were which he doubted fixity so variation patterns = complicated species were specially created?? No they EVOLVED why are there less abiotic interactions in tropical forest? Temperate forests = species is low so diversity is low so opportunity for biotic interaction is low Winter = everything stops, life cycles close Trap line = particular forager = pollinator has a particular route in a day Trap line don’t has to be a big route Germ plasm theory = lamarc was not correct about inheritance If blacksmith is strong than offspring also has to be strong = WRONG Trait correlated with utility = trait utility Phenotypic environment Natural selection is mechanism that drives adaptive radiation Convergent evolution Unrelated species look similar because of similar pressures Divergent evolution Particular species than is exposed to diff pressures so overtime they evolve find more resources at oneclass.com find more resources at oneclass.comParticular species than is exposed to diff pressures so overtime they evolve differently = speciation Overtime diff species evolve diff adaptations = so if you make a hybrid = genetic problems Genetic drift = random change in genetics = evolution, unimportant Drift is promoted by small pop Stochastic = random GLOBAL WARMING = EVOLUTION, MIGRATION, ADAPTATION, EXTINCTION find more resources at oneclass.com find more resources at oneclass.com-Genetic Polymorphism - the occurence of more than one morphology type, for example, a colour polymorphism (in which a plant can be too or three different colours). However, it is important to keep in mind that polymorphism also refers to many genes. -High genetic variability is when there are many alleles that be responsible for a trait. -Some genes don't necessarily affect fitness. Having one allele or another allele doesn't really affect your fitness. However, Theres evidence that sometimes these neutral genes can have a small difference in organisms, thus we define these as nearly neutral mutations. Balancing selection: theres a heterozygous advantage. Important question: What would happen if you only had a heterozygous locus? If all species were heterozygous? They would be asexual or clones. In heterozygous species, they will always be mating and because we get genes from both of our parents, we will always have homogenous species. Thus, if there is a heterozygous advantage, this ensures variability. Why? Because it ensures that theres always homogeneous and heterozygous and not just one phenotype but rather multiple. This is why the balance school was generally right. If heterozygosity is not favoured, then certain species cannot adapt to the changes to the environment. Polymorphism is very important because it ensures the survival and adaptation of multiple species. For example, humans have multiple alleles responsible for the type of immune system that we have. If theres 50 alleles that can code for tthese systems it shows that theres a lot of genetic variability. No need to worry too much about trsnponsable genes Co dominance why so important? If you have a gene that shows dominance and recessiveness, you cant tell theres a recessive until multiple generations after. Through the phenotypes, we can tell the frequency of the homozygous recessive, however, we cant tell the difference between the homozygous dominantand the heterozygous and thus, if we wanna see it physically we have to breed it. In other words, before we can actually see if its dominant heterozygous or dominant homogeneous, we always have to wait until the next generation. This is really time consuming and thus its better to see the heterozygous genes that show co dominance. A generalist ( wild type) contains a lot more genetic variability than the specialist type. Specialist only occurs in rice fields Tutorial 2 09/27/16 Tuesday, September 27, 2016 8:21 PM find more resources at oneclass.com find more resources at oneclass.comfind more resources at oneclass.com find more resources at oneclass.comTopics & Concepts ○ Dynamic not static world ○ No purpose • Controversies of Evolu. ○ Lemark's mechanism for evolution ○ Wrong = linear not branched system ○ Individuals change phenotypes and pass to offspring (wrong) • Inheritance of acquired characters Inherited by only germ cells, somatic cells do not function as agents of heriditity ○ ○ Soma - gametes- off spring = IMPOSSIBLE ○ Genetic info only go from genes to protein ----not reverse • Germ plasm theory Beagle ship, 20 years, natralist, gather evidence, gathered many variations btw one species* ○ ○ Used scientific method aka experiments (lamark no) ○ Essay before ○ 1856 begin writing • Publication of "origin of species" ○ Lyell's book principles of geology • Gradualism • Descent with modification ○ Malthus essay ○ Carrying capacity ○ Galapagos finches • Natural selection Lecture 2 Darwin's big idea and how it changed biolo Friday, October 7, 2016 11:07 PM find more resources at oneclass.com find more resources at oneclass.comogy find more resources at oneclass.com find more resources at oneclass.com○ Galapagos finches ○ Favourable adaptions preserved, unfav = destroyed a. Variation -idvs. In a pop. b. Heredity - genetic inheritance Selection - some better adapted forms survive, less adapted die off (OFFSPRING is key) c. • Requirements for evolution ○ Book genesis ○ Purposful, creator, 6 days ○ Intelligent design ○ No observations, no testable hypotheses • Creation "science" is not science find more resources at oneclass.com find more resources at oneclass.comScanned by CamScanner find more resources at oneclass.com find more resources at oneclass.comScanned by CamScanner find more resources at oneclass.com find more resources at oneclass.comScanned by CamScanner find more resources at oneclass.com find more resources at oneclass.com• Frequency dependence: It dictates the fitness of a moprh or of an individual. For example if a rare morph arrives at a place where he is unique and where he can mate with all other morphs, then frequency dependence will cause equilibrium and maximize the fitness of that rare breed. In other words, frequency dependence ensures that all types in a polymorphic species are kept at equilibrium, or else it will lead to speciation and genetic drift. • Why is the rate at 1:1? Why is this the ratio? Why are humans and most species 1:1? • The ultimate explanation according to the professor is frequency dependence. This particular ratio maximizes the fitness of individuals and it ensures gene flow. If only females could mate with one another it does not favour the gene flow and the sharing of new genes that comes with having males. Therefore males are genetically important (yay) • Why do some organism live a lot longer than others? • Heterozygousity really increases fitness. • A study showed that older individuals were more heterozygous. The most heterozygous individuals were considerable the oldest. They did a study on trees to see the difference between the old and young trees. Most of these young trees were homozygous and the old trees were heterozygous. In these trees, it is also important to note that there was some inbreeding. This explains why some are homozygous and some are heterozygous. What happened? Why are these heterozygous able to survive longer? Depression. Natural selection overtime is taking out the most homozygous individuals and thus, the ones that are surviving the longest time tend to be heterozygous. Natural selection will take out individuals who are keeping deleterious genes. The homozygous ones are not able to endure large changes or drastic environmental changes. As a result, they tend to die. Natural selection ensures that the heterozygous trees survive and that genes are being share. This is also a problem in zoos, where a lot of the animals are super homozygous, because when let out in the wild, they wont generally last long. • Pay attention to the triangle with the monomorphism,dimorphism and trimorphism • Generally speaking, adaption is always a result of natural selection. Genetic drift cannot generally lead to adaptation! Genetic drift is a small change of genes. Its super small and occasionally may be involve in selection. Generally, drift has negative consequences because it leads to less variability in populations. Tutorial 3 Monday, October 10, 2016 11:37 PM find more resources at oneclass.com find more resources at oneclass.comfind more resources at oneclass.com find more resources at oneclass.comconsequences because it leads to less variability in populations. • If you have a small population, you will lose the some alleles that although might be damaging, you also run the chance of losing alleles that could be beneficial. • What EVEN IS GENETIC DRIFT? Good Analogy • Is when the rarest alleles are generally be lost, leading to speciation. If you have a bag of 200 balls (which can make 100 species) HE REALLY EMPHASIZES THIS, HE SAID THAT THE NUMBER OF SPECIES THAT CAN BE MADE IS HALF THE NUMBER OF GAMETES. Anyways, if you have 200 balls and you have 4 different types of balls and one has a really low frequency (red 5% blue 30% yellow 50% and green 20%} one would generally be lost. For example, if lets say pick 20 balls in every generation, the one with the less frequency will eventually be lost. This is an example of a small population, showing how overtime, the red ball or the red allele will disappear. Same thing, if theres a huge population drop and theres only 5 balls picked. Theres a HIGH CHANCE THAT you will not pick the red ball (5% frequncy). find more resources at oneclass.com find more resources at oneclass.com• Differences btw tropical vs. temperate ecosystems TROPICAL TEMPERATE • V high species diversity • Biotic interactions • Coevoleved mutualism • Warm • More opp. For nat. sel. And evolu. • Rapid insect and microbial pop. Growth Individuals in same species separated by large distances, not good for reproduction b/ wind pollination must travel far. • • Bc of ^ point • Bc dense canopies = wind poor agent • Bees, butterflies, birds, bats • animals pollinate • Pest & disease pressures more intense • Lower Wind pollinated • Neighbors = same species • ○ Biotic factors less impt. Than abiotic ex) artic • Biotic vs abiotic factors • Animal pollination ○ Ant-Plant mutualism ○ Ant: shelter, protein, floral nectar ○ Plants: saved from herbivore insects ○ Tested with tangle foot ○ Frederikson experiment *reciprocating evolution = plants and herbivores exert pressures and create defences ○ • Mutualism ○ Tropical tree seedlings don’t stay close to parent • Pest pressure Lecture 3 "What Darwin saw: a geographical perspec on biodiversity and adaptation" Friday, October 7, 2016 11:55 PM find more resources at oneclass.com find more resources at oneclass.comctive find more resources at oneclass.com find more resources at oneclass.com○ Tropical tree seedlings don’t stay close to parent ○ Die if closer • Plant herbivory ○ Red bracts on coffee plant • Field experiments ○ Common in tropics ○ Incr species div. ○ Occur on other plants ○ Convergent evolu.= evolved indep. In many unrelated families • Epiphytes • Convergent evolu. ○ From a single common ancestor = many species with different traits Features: common ancestry, phenotype-enviro correlation, trait utility, rapid speciation ○ ○ Ex) Galapagos finches ○ Ex) tortoises • Adaptive radiation • Flightless birds • Sexual dimorphism • Endemism = species that are rrestricted to a particular geographic region • Geographical isolation ○ Evidence of speciation ○ Flora and fauna colonized from mainland • Galapagos islands ○ Temperate ○ Net balance of species diversity = speciation rate vs. extinsion rate ○ • Patagonia ○ Endemism ○ Koala & eucalyptus • Australia find more resources at oneclass.com find more resources at oneclass.comLecture 4 NeoDarwinsim and the evolu. Sig of genetic variation Possible Questions 1. Where does genetic variation come from? 2. How is it inherited? 3. How does it influence trait variation? 4. Why is genetic variation important for evolution? Topics & Concepts  Genotype = genetic constitution of an org. ex) Aa  Phenotype = org. as observed (trait)  Genome = entire seq. of dna  Dna = genetic makeup  Gene = functional unit of inheritance, on a chromosome of DNA, composed of codons (3 neculeotides)  Allele- two copies of a gene, inherit one allele from each parent at random  Genetic variation comes from o Mutation--ultimate -long term o Mostly---Indep. Assortment and recombination during meiosis--long term o Recombination-- btw generations o Gene flow o Hybridization  Mutation o Stable changes in DNA, changes genotype, low rae, must occur in germ cells, can be neutral, good, bad on phenotypes and fitness o Unstoppable, random, rate varies in diff organisms, can create polymorphism (phenotypes co-exist)  Fitness effects of mutations o Fitness affects context o Depending on the environment o The enviro of the individual affects mutations and its affects  Transposable genetic elements = McClintok jumping genes  Blending and particulate inheritance o Blending- when offspring of a cross show intermediate phenotype o Particulate- inheritance determined by genes  Discrete/discontinuous (inherited by 1 or 2 genes, dominance and excessiveness, = mendelian) vs continuous traits/quantitative genetics (complex inheritance many genes, polygenes, selection response = quantitative inheritance) o Mendelian vs quantitative genetics  Genetic polymorphism o Involves morphs governed by segregation of a small # of alleles at 1-2 major genes  Fisher's fundamental theorem- the rate of inc. in fitness pf a pop. At any time is its genetic variance in fitness at that time find more resources at oneclass.com find more resources at oneclass.comfind more resources at oneclass.com find more resources at oneclass.comfind more resources at oneclass.com find more resources at oneclass.comfind more resources at oneclass.com find more resources at oneclass.comfind more resources at oneclass.com find more resources at oneclass.comNeo-darwinism = harmonization of population genetics with darwinian natural selection • Polymorphism- the fraction of genes that are variable-P-proportion of gene loci that are polymorphic • • Heterozygosity -H- average freq. of heterozygous individuals per gene locus ○ Mutation (incr) ○ Recombination (incr) ○ Random genetic drift *important when pop. Becomes small (decr.) § Purifying (-) reduce fitness § Adaptation (+) incr fitness § Balancing (maintains diversity) ○ Natural selection (incr and decr) • Processes affecting genetic diversity ○ Controlled breeding and selection of indiv. For many generations ○ Abundant genetic variation exists for polygenic traits • Artificial selection on quantitative traits Topics and concepts • Classical vs balance schools of pop. Structure • Major Q: what proportion of genes are variable (polymorphic)? • Lecture 5 The maintenance and measurement of gen variation Saturday, October 8, 2016 1:36 PM find more resources at oneclass.com find more resources at oneclass.comnetic find more resources at oneclass.com find more resources at oneclass.com○ Allozyme = diff forms of the same protein ○ Answers the major Q ^ Empirical evidence supporting balance school bc measuring diversity at genes controlling enzymes and proteins ○ ○ Benefits: large scale, using genes as markers to study evolution • Enzyme electrophoresis ○ Rare- specialist- low diversity ○ Generalist-widespread-high diversity • Dna sequence diversity DNA sequencing allows differences between individuals in single nucleotides to be identified ○ SNP's = single nucleotide polymorphisms can be measured for thousand of genes *humans made of this • ○ Human genome project ○ Differ by 1000s of SNPs • Genome sequenceing find more resources at oneclass.com find more resources at oneclass.com• reproductive modes ○ Both sexual and clonal = perennial plants ○ Both sexual and asexual = water fleas in diff enviro • ○ So many costs, what are the benefits • paradox of the evolution of sex ○ time and energy to find and attract mates ○ • increased energetic costs • ○ risk of predation & infection • ○ cost of producing males • ○ 50% less genetic transmission ○ break up of adaptive genes combinations • costs of sex ○ 50% less genetic transmission compared to asexual ○ Gene cloning ability is transmitted more • Transmission bias ○ Lottery model- one ticket and photocopy, or buy many tickets, enviro is not uniform ○ Tangled Bank = spacial heterogenious, patchy enviro ○ Red Queen hypotheses= temporal variability, enviro temp. = changing = diseases an • Advantages of sex ○ Slower to recombine/eliminate mutations compared to sex ○ More common in homogenous enviros ○ More common in invertebrates and plants • Asexuality/clonal reproduction • Parthenogenesis ○ A rare case of ancient asexuality in which males are unknown but diversification ha ○ No sex millions of years ○ WHY • Bdelloid rotifers Topics & concepts Lecture 6: Organismal reproductive diversity Sunday, October 9, 2016 12:47 PM find more resources at oneclass.com find more resources at oneclass.comm, spatial variable nd pathogens as led to > 300 spp. find more resources at oneclass.com find more resources at oneclass.com• Dioecy • Hermaphroditism ○ Relatives vs random mates • inbreeding & outbreeding ○ Genotypic frequencies changed ○ Allele frequencies unchanged ○ Heterozygosity reduced by 50% per generation with self-fertilization ○ Homozygosity for deleterious recessive alleles results in inbreeding depression ○ Fitness can plummet • genetic consequences of inbreeding ○ Decr: fitness, viability, fertility ○ How plants stop inbreeding • inbreeding depression • evolution of selfing ○ Long diss dispersal favours selfing forms bc a single indv. Can start a colony w/o ma • Baker’s Law ○ Fisher ○ Selfing form has a transmission adv. ○ Quantity argument • automatic selection of a selfing gene find more resources at oneclass.com find more resources at oneclass.comates or pollinators find more resources at oneclass.com find more resources at oneclass.comgeographic variation=What proportion of all genetic variation in a species is due to differences between populations? • population differentiation=How much of the observed variation among individuals is genetic in origin? • ○ the movement of genes across the landscape To measure: difficult, use neutral genetic markers, frequency of heterozygotes - estimate ○ Most gene flow occurs over a short distance, but a small amount occurs as far as 1 km ○