Final Exam Notes & Review! (1/2)
Final Exam Notes & Review! (1/2) BISC 1006
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Date Created: 03/22/16
Notes Preview (complete set starts on pg 4) Notes Preview = Part 2/2 Fossils You see em in layers (__) that tells us how old they are! Sediment is deposited @ the ___ of aquatic systems (water) o Help preserve + date organisms that lived during that time! o Over time, they stack up like bean dip o Each layer of the bean dip is a different time period! o (lower down it is, the older it is) Traces of evolution Fish, turtles, chicken, cats & humans ALL DEVELOP SIMILARLY Bruh we all look the same in the womb ^it's bc we have a COMMON ___ o Over time, we were reproductively isolated o Humans developed legs while snakes didn't o ^we still have a tail bone tho! ^bc we're so similar, we can look @ other animals and see effects and how they play out Convergent Evolution Similar environmental pressure >> similar adaptations! 2 different species evolve @ the same time ^ they end up with ___ looking/structures Analogus ___ Vestigial Different forms but structures look 2 diff species have same bone Organs that aren't used the same! structure bc they came from a legs on a snake common ancestor! Tail on humans They're ___ or degenerated bc we don't need em! All we have left is our tail bone Snakes just have tiny leg bones Notes Preview (complete set starts on pg 4) Notes Preview (complete set starts on pg 4) Stabilizing: all the in __ are selected for! o Aka Goldilocks selection "just right, not too big or small" o Species in the middle of the spectrum (__!) are chosen to reproduce & survive (Goldilocks chose baby bear's bowl!) o Bad news for the __! (aka mama & papa bear's bowl) DNA Tells us the difference btw a moth & a human & a frog etc Sometimes DNA is so similar it's hard to tell! o So we look @ sequence and __!! o We're v similar to pumpkins, but the TIMING makes us closer to monkeys CLICKER Q - What type of evolution isn't random? a. Gene flow b. Genetic drift c. The founder effect d. Natural selection - helps the population be more adapted to its environment! Pick and choose e. Mutation What is Evolution? Thursday, January 21, 2016 We're all cell based! We pass down genes >> our kids Kids >> reproduce, grow + develop! Energy input/output Some use light (photosynthesis!) Others use chemical (us!) thru eating/digesting producers "Sense & Respond" - how did we become complex? Has a lot to do w/ sensory organs! Evolution = change of a group over time! (slow) Population based Micro (small scale) > macroevolution (large scale) There's exceptions: bacteria/archaea can't have sex lol Big Bang Happened 13.7 Billion Years ago!! o Tons of particles/matter formed the Earth & Sun! o ^that matter changed the composition of the water & atmosphere o ^conditions made it possible for atoms of carbohydrates n shi to form o ^that helped form the Earth & make orgs alive! Earth formed 4.6 b.y.a Life started @ 3.8 b.y.a Carbon dating/radiometric testing = tells you how old something is! o You can test a sample from sediment/wood to see! o All life is carbon based yall o HOW - we know unstable forms of elements have Different rates of decay Different timescales ^we calc that stuff to see how much is left! (age) Fossils = proof of evolution! o Pieces of the past Imprints (footprints) Remains (bones) o Sedimentary rock Old stuff that buried the fossils We don't have all the answers - There's a lot of "missing links" 99.9% of all species that ever lived are extinct! :( How do we group LIFE? Broad v narrow levels o Broad = General features are similar Narrow = All features are similar Organism types Eukaryotes Prokaryotes Evolved when a group of bacteria took light >> chemial energy! Microscopic, single celled orgs that reproduce asexually! Bacteria ^before this point, there wasn't any oxygen in the atmosphere. o Resemble ancient forms of life Now they use oxygen! Early eukaryotes engulfed bacteria & o Have multiple nutritional strategies (both mitochondria that >> more energy!! producers and consumers) More energy >> bigger more complex org! o Pathogenic relationships! Protists: simplistic Archaea Plants: use photosynthesis o More advanced cell features Fungi: key decomposers! Animals: most complex o ^are like us bc more complex rxns (>> more energy >> can build bigger molecules) o Not pathogenic! Symbiosis = close association w/ another species! Mark from work and I really get along - symbiotic relationship "You make food, I'm keeping you!" Key process when eukaryotes evolved! o Mutualism is a type of symbiosis EXS: o Strep bacteria in your bod o Parasites o Commensalism o Exploitative Endosymbiosis = process of symbiosis where an ancestral eukaryotic cell establishes a symbiotic (mutualistic) relationship w a prokaryotic cell o Mitochondria >> evolution of eukaryotes as a whole o Chloroplasts >> evolution of plants & algae! o Let prokaryotes become MO COMPLEX! (multicellular) o w/o endosymbiosis, we wouldn't have enough energy or food on earth to supply the complexity! Protists & Timeline of Evolution! Tuesday, January 26, 2016 WTF how did we get so complicated? Protists engulfed mitochondria, which let em get BIGGER MO energy producers mean they can be MO complex MO complexity >> MO diversity! CLICKER Q: Which group of Eukaryotes is responsible for the greatest amount of nutrient recycling? a. Fungi b. Vertebrate animals c. Protists d. Plants e. Invertebrate animals CLICKER Q: All organisms f. move g. sexual reproduce h. make their own food i. grow j. capture sunlight Protists = larger more complex group of eukaryotes! HAVE MITOCCHONDRIA so can grow bigga into o Zooplankton (consumers) o Phytoplankton (producers) o Plasmodium (pathogens) Can build bigger, more sophisticated molecules ~ ~ sexual reproduction ~ ~ (mutations make more variation!) AND Asexual (if you die, offspring dies too!) "Formanifera" oType of protist w/ big impact oTests on em tell us what climate change is like! o ^they're how we test global warming TIMELINE Precambrian Cambrian Silurian Devonian Carboniferous Origin of life! Huge Inc ^ in fishie Inc ^ in Earth gets Plants were the increase in diversity of land plant covered by big guys diversity! Insects + diversity forests Photosynthesis MO algae invertebrates start 1st 1st reptiles show = oxygen 1st to colonize the amphibians up! added to the vertebrates land colonize the atmosphere! aye (insects) land (frogs) First eukaryotes Mass (multicelled extinction orgs)showed up @ the end of this period multicellular organisms: showed up 650 mya in the oceans 540-490 mya: major ^^increase in fossils Fungi oSingle celled oRigid cells = have chitin oConsumers = absorptive heterotrophs aka they eat organic material & break it down (IMAGINE spitting on the ground, putting your hand on top and absorbing the nutrients lol) oV key decomposers! Spiders & Millipedes (invertebrates) Amphibians Embryonic Body Plan = Via sexual reproduction Body symmetry made gathering food more efficient! Egg & sperm come together Then move to become a specific tissue type & organ Bio Evolution Tuesday, February 2, 2016 Evolution = change in populations over time! There's 4 ways to evolve - 1. Mutations 2. Gene flow 3. Genetic drift 4. Natural selection Key Players Lyell o The earth is still changing and everyday processes >> constant change of the strata Lamarck: o Got some stuff right, some wrong! Right Wrong o Evolution explains why we have o Structures you use get fossils! bigger/better, those that aren’t o Current diversity of life shows deteriorate how old the earth is! o Acquired characteristics are past o Line of descent that leads>>modern species down to offspring o Adaptation to the environment is a primary product of evolution Biological Evolution ppl!! (Thought evolution is descent w/ modification & natural selection) Charles Darwin College dropout! LEGACY - Travelled on the HMS Beagle boat and observed/collected fossils of plants & animals o He noticed most animals in Europe part looked the same but the GALAPAGOS islands had tons of variety o Unique subspecies! oGiant tortoises oFinches (birds) - physically v unique & distinct types! ~10+ Darwin tried to explain WHY! Alfred Wallace… o Other = equally imp evolution guy o Came up w/ natural selection o Some of his ideas whack - "if you build big muscles your kids will have em too" "if you dye your hair blue your kids will too" o "Wallace's line" - split species groups into north (asian) & south (austrailia) to categorize why environment changes what you look like! Henry Walter Bates… o Mimicry Words to live by… All life is linked thru a common ancestor! Populations (of living things) change over time! o ^influenced by the environment Well suited characteristics get "selected" to pass on vs traits that aren't o Long fins in the ocean is good o Short fins - swim slower, easier target for predators! Natural selection observations 1. If everyone has equal fertility, populations should exponentially grow! i. Everyone should have the same # of kids who can live & reproduce too 2. Most populations fluctuate growth (not exponential!) bc of resource availability i. It doesn't matter if you have a fancy way of swimming if you don't have kids! To pass your genes on to 3. Environmental resources are limited i. They're not gonna be available to everyone in the population! ii. ^there's competition for ex Inferences (what it all MEANS) There's a #STRUGGLE to survive (only a few make it!) Parent's genes influence how you survive & whether or not you can have kids! (fertility) Differences/variations are inherited Populations change over time! How do we know evolution is happening? In any given room, street, club, airport, there's a unique gene pool! o Some blue, green, brown eyed ppl! o Recent shift >> blue eyes o If that shift is occurring, we know evolution is happnin! o ^ppl who have colored eyes are favored/selected to reproduce EX - in a sports arena, say all green jerseys survive & blue don't o Colors!!!! are alleles o ^that same kinda variation happens in our population GENES Presence & proportion of gene types (alleles) affects what the population will look like! Over time the environment changes o When we knock down forests, we change the natural selection in that environment! o ^shifts the ALLELE FREQUENCY EX: Frogs Population A Population B Increase light alleles/characteristicincrease dark alleles/characteristics 4 ways to Evolve Thursday, February 4, 2016 RECAP = evolution is the shift of genetic variation over time!! Only on the population level, NOT individual! Variation is important so we can adapt to our environment yo What 4 ways do species evolve? 1. Mutations: change in the DNA sequence o Random event! o Can be Harmful Beneficial Neutral o "Sequences" tell what proteins to make (hair/eye color, physical traits) This is why we look unique! Explains variation in the population o All variation comes from genetic recombination! (<exactly what it sounds like) o Only 2% of your genome codes for genes! The other 98% doesn't make proteins (for traits) GOOD mutations= sickle cell (protects against malaria) ability to talk (essential to human comm) permanent breasts?(fun to play w?) BAD mutations= Prosopagnosia (can't recognize faces) Marfan's (elongated limbs make it hard to walk - slender & lincoln) 2. Gene flow: exchanging alleles (genes) btw 2 different populations o Random accident! o New alleles come in o Old alleles get thrown out (are removed) o If population A + B are v similar bc of gene flow, why does A survive instead of B? Environment! B might not be suited to their habitat/environment ^ they have the same traits but one species can survive better HISTORY TIME: oThe human pop has developed melanin near the equator to absorb vitamin D and protect against UV rays! oIn 50 years, nat geo thinks we'll have a mid tan skin tone like: 1. Genetic Drift: o Rando events! >> differences in individual's ability to reproduce/survive o Not based on any characteristic! o Happens bc of ENVIRONMENT EX: Windstorms by chance blow away some flowers and leave others to survive o Genetic drift >> Bottleneck After 2 reproductive events, (drifts) you lose genetic variation! V important to small populations! Bottleneck >> fixation fix: there's only 1 allele so variation is fixated/limited to 1 can be bad, good or meh Speeds up extinction! o Founder effect = genetic drift when new populations are founded! Whoever finds/establishes it determine what the genetic variation will be! EX - white penguins of the OG population break away (est a new one) and now there's no variation (all white erything) Genetic Drift Exs: (in humans) o Royal fam incest - restricted reproduction! You keep harmful alleles that could >> mental illness o Infection - doesn't target you specifically but gene variation would determine if you survive or nah! o Pangaea breaking apart o Tsunamis/hurricane Katrina - disaster didn't target ppl, death was random! 2. Natural Selection: o When ppl w/favorable traits have higher rate of survival/reproduction! o It steers the pop to be more adapted to their environment o Types Directional: moths! Species w/ characteristics on one end of the spectrum are chosen for! Population shifted from dark > light The dark ones blended into the trees, so predators couldn't see/eat them (THEY SURVIVED!) In lighter environments, the white moths blended into white trees and black ones were picked off (THEY WERE NATURALLY SELECTED FOR) ^^ bc of pollution Stabilizing: all the in betweeners are selected for! o Aka Goldilocks selection "just right, not too big or small" o Species in the middle of the spectrum (averages!) are chosen to reproduce & survive (Goldilocks chose baby bear's bowl!) o Bad news for the extremes! (aka mama & papa bear's bowl) Disruptive: both ends of the spectrum are selected. o The middle ones are outta luck! Sexual selection o Type of natural selection! o You can only mate w/ organisms of your SAME SPECIES o "sexual dimorphism" = males and females in the population don't look like each other! Peacocks… Lions… Flamingos.. Science of Sex Appeal & Evidence of Evolution Tuesday, February 9, 2016 Sexual selection = why are certain physical characteristics on males instead of females? You can only mate w/ organisms of your SAME SPECIES Female has CHOICE on who she uses her egg on o She's got more to lose! Male has COMPETITION w other males o Not investing that much! Peacocks = size MATTERS! o Males w/ bigger tails had more testosterone, but maybe more damage o Females chose males w more eyespots! o ^ eyespots are genetic markers for being healthy! o Changes depending on the season! Natural + Sexual selection are getting @ being better adapted to the environment! So you can survive & reproduce. NOT about crafting the "perfect" organism Science of Sex Appeal The pic below is a mix of 5 different women! SAME women @ different times of the month! (left is ovulating, right is menstruating) We look for o Femininity (curves) o Attractiveness (symmetrical face) o Health (good skin, hair that isn't falling out) SHOW ME THE PROOF 6 evidences of evolution 1. Fossils 2. Traces of evolutionary history (comparing what ancestors looked like v now!) 3. Similarities & divergences in DNA (mimicking it in the lab! To test) 4. Direct observations of genetic change in populations (watching animal planet style) 5. Geographic distribution of organisms + fossils (before or after pangea?) 6. New species are still being formed today! Fossils You see em in layers (sediment) that tells us how old they are! Sediment is deposited @ the bottom of aquatic systems (water) o Help preserve + date organisms that lived during that time! o Over time, they stack up like bean dip o Each layer of the bean dip is a different time period! o (lower down it is, the older it is) Traces of evolution Fish, turtles, chicken, cats & humans ALL DEVELOP SIMILARLY Bruh we all look the same in the womb ^it's bc we have a COMMON ANCESTOR o Over time, we were reproductively isolated o Humans developed legs while snakes didn't o ^we still have a tail bone tho! ^bc we're so similar, we can look @ other animals and see effects and how they play out Convergent Evolution Similar environmental pressure >> similar adaptations! 2 different species evolve @ the same time ^ they end up with different looking/structures Analogus Homologus Vestigial Different forms but structures look 2 diff species have same bone Organs that aren't used the same! structure bc they came from a legs on a snake common ancestor! Tail on humans They're reduced or degenerated bc we don't need em! All we have left is our tail bone Snakes just have tiny leg bones DNA Tells us the difference btw a moth & a human & a frog etc Sometimes DNA is so similar it's hard to tell! o So we look @ sequence and timing!! o We're v similar to pumpkins, but the TIMING makes us closer to monkeys CLICKER Q - What type of evolution isn't random? a. Gene flow b. Genetic drift c. The founder effect d. Natural selection - helps the population be more adapted to its environment! Pick and choose e. Mutation How we influence evolution Thursday, February 11, 2016 We influence population evolution through direct observation! BREEDING We select for certain characteristics o Domesticated dogs (common ancestor was a wolf) o Plants and farming crops ^artificial selection = process where only individuals w/ certain characteristics are selected to breed! o Shifts the population to one side using genetic variation (directional selection!) Geographic Distribution is how we spread genetic variation Pangea = OG supercontinent Continental drift = continents move based on what's happenin below the ground! (tectonic plates) We sort em into before/after pangea broke up! o BEFORE - lungfish were only in the 1 supercontinent o AFTER - represent all the lungfish species around the world! Macroevolution! Micro >> macroevolution Macro = rapid evolutionary change bc of environmental conditions Harsh conditions o Droughts affect food supply! o ^ nut size led to >> evolution of beak size! o ^ over time, if you're eating bigga nuts, you'll evolve to have bigger beaks (Darwin finches) CLICKER = characteristic/gene change >> towards one side is called "directional selection" HOW DO PROKARYOTES EVOLVE? Biological Species Concept Says species are legit if they can have sex & produce viable offspring. Oh and they have to be reproductively isolated EXCLUDES bacteria & archaea (asexual reproducers) & prokaryotes Prokaryotes Evolution (2 ways!) 1. Sex - exchange gene info asexually! i. Sex Pillet (tunnel) ii. Transformation (pick up DNA from the outside world) iii. Transduction (exchange DNA via infection/viruses) 2. Conjugation - connection btw living & bacteria! What's the BIG IDEA = there's a ton of ways to increase complexity! Even tiny creatures can have sex! Belly button project - study found 1000s of microorgs in your hole Macroevolution Tuesday, February 16, 2016 Looking from small >> big events Micro >> macroevolution Human Interventions that affect formation of species around the globe We affect gene pools by DESTROYING + SELECTING o Deforestation - eliminates habitats Pollution - o Affects quality of the air o Microorgs in the water @ risk! Oil spills - runoff kills micro/macroorganisms & producers o Changes the aquatic biome! Breeding - artificial selection o Animals o Crops are genetically modified Hunting - we eat and reduce # of animals What are SPECIES? "smallest most exclusive group" ^ some of em can reproduce asexually thoach other to produce fertile offspring" We classify em into - Morphological Biological more commonly used) Physical features! Reproduction! Those who look alike are Being able to have sex & grouped to be a species produce viable offspring but are reproductively isolated EXCLUDES = male & EXCLUDES = all asexual female who have sexual reproducers & hybrids! dimorphism (…) bacteria do it alone (they have both parts) hybrids can be hermaphrodites & plants can do genetic tricks to multiply their own DNA NOW Genetic Species Concept May have sex to get characteristics from each other Groups orgs w/ a common gene pool aka similar DNA Reproductive community that forms a genetic unit SO HOW DO WE BECOME DIFFERENT SPECIES ? We have to be reproductively isolated to be considered different species from our ancestors!! Species form when they're separated (isolated!) as time passes, evolution happens! Speciation = makes populations more biodiverse! o Process where 1 species splits >> 2 or more o The 2 new species are reproductively isolated o Over time, they keep splitting so they can't interbreed! o ^ there are pre + post zygotic barriers in their way Enough time has to pass having no sex!! When gene flow ain't happenin, they won't mate later on o Kinda like when you move away from your 5th grade bf, meet up 15 years later in college and aren't attracted anymore o There's 2 barriers to gene flow: 1. Pre zygotic 2. Post zygotic 4 PREZYGOTIC BARRIERS = (aka before sex/egg fertilization) 1. Temporal isolation o Mile high club - 2 species mate @ different times o Feeding + being active too! o ^this chick is always sleeping (hibernating) so we can't have sex 2. Geographic isolation…easiest! o Aka allopatric speciation o This barrier helps keep you away from your boo (sexual partner) Mountains, flooded valleys & seas are all barriers While they were apart, mutation, gene flow, genetic drift happened. So once they met up again, they couldn't have sex bc considered diff species! Insert iphone convo comic strip [you're like a whole other species! It's been too long! I can't mate w you anymore!!] Habitat diffs mean they can't live in the same place! 3. Behavioral isolation o He doesn't get "up" or she isn't feeling it o Mating that NEEDS dance o 2 species don't respond well to courtship 4. Mechanical isolation o Snails have gametes on the wrong side, so they can't mate 5. Gametic isolation Last step fails! smh Sperm & egg come together but can't produce a healthy offspring! Sea urchins (firework lookin)> Can only fuse w/ eachothers' gametes POST-ZYGOTIC BARRIERS (after formation, this keeps eggs from growing into healthy offspring) Zygotic Death = after sex, the zygote dies so it can't grow up Poor Hybrid performance = ligers and zonkeys and narlugas OH MY o Usually infertile o Hybrids can't produce sperm/egg that lets you produce a viable offspring o ^EXCEPT plants which are super cool and hybrid all the time Narluga (Narwhal + Beluga) Zonkey (Zebra + Donkey) Liger (lion + tiger)
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