Final Exam Bundle: Units 3 & 4
Final Exam Bundle: Units 3 & 4 BIOL 1108
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Date Created: 12/09/15
Guest Lecturer Anatomy amp Physiology Wednesday ctober 7 2 15 1219 PM 0 2 guys Earnest Starling and William Bayliss became interested in some research other guys were doing in which extracts of the adrenal glands were taken 0 Adrenal gland extracts were blended in a blender mixed with saline solution filtered it and injected it into many different types of animals Killed animals but side effects were observed as they were dying o Adrenal glands make adrenaline O Starling and Bayliss wanted to see if there was something to this bc the body communicates longdistance through the nervous system but these chemicals were causing long distance effects 0 There was a powerful man in Russia Pavlov insisted definitively that all longdistance communication was strictly neurological I Starling and Bayliss said no chemicals can communicate to the body longdistance too 0 Bayliss and Starling set up an experiment with dogs 0 Anesthetized dog and isolated part of digestive tract The nerves supplying loop ofjejunum were dissected and divided so it was only connected to the rest of the body only by blood vessels 0 Weak HCl was added to the duodenum Secretion of the pancreas occurred and continued for a few minutes 0 Then acid was added to the jejunum and a similarly large secretion was produced quotThen it must be a chemical reflexquot Determined to be secretin 0 He rapidly cut off a piece of the jejunum and filtered it and injected it into the jugular of another animal that animal39s pancreas secreted the same thing 0 3 million years ago 0 Life was simpler 0 Goals I food in I waste out I stay comfortable I move if you39re not happy or alter activity to accommodate change 0 Life became multicellular 0 Individual cells could not move if an environment became uncomfortable 0 Each cell works for the survival and comfort of every cell 0 So how do all those cells know when things are changing for cells far away communication Long Distance Chemical Signaling Hormones in the Endocrine System 0 Learning Objectives 0 Compare and contrast nervous and endocrine 0 Identify major classes of chemical messengers used for long distance comm 0 Survey some of the representative messengers their pathways and effects 0 Cellular Communication Mechanisms Biology Page 1 T e of Ran e S eed yp g It s kmd of like Duration of effect Communication and Specrfrcrty cell39tOmll contact very short range 1 391 passing a note in class gap jxns 39 aracrine short range mailing invitations to a few p neighborhood specific neighbors long range f t t teX ng neuronal hi M s 39ezsi 39 well really it s more like milliseconds g y p Snapchat longrange slower dropping thousands of ENDOCRINE widespread party invitations out of an seconds minutesyears but still specific airplane over Athens o Celltocell very short range 0 Paracrine a cell makes a chemical and secretes it to the outside Chemical does not travel far and usually stays in interstitial fluid Only cells in nearby tissues are affected 0 Neuronal Myelination and diameter affects speed of signal Specificity depends on what cells axon goes to O Endocrine Specificity varies 0 Endocrine communication Major endocrine glands Hypothalamus Plneal gland Pituitary gland quot Thyroid gland Li Parathyroid glands behind thyroid Adrenal glands atop kidneys Pancreas Ovaries female Testes male Organs containing endocrine cells Thymus 7 Heart Liver Stomach Kidneys Hormone Chemical messenger secreted into the blood for transport to distant cells all over the body 0 Hormones 0 Amino acid based I Tyrosine and tryptophan can be modified into hormones III Tyrosine gt Adrenaline aka Epinephrine and norepinephrine III Tryptophangt Serotonin Melatonin I Short polypeptides and whole proteins Biology Page 2 o Steroids derived from cholesterol 0 Response to hormone I Response depends on whether the hormone is hydrophilic or hydrophobic I Hydrophobic lipidsoluble hormones can easily pass through lipid bilayer effects are deep within the cell Ex testosterone I Watersoluble hormones can39t enter target cell I Response determines III Method of transport in blood III Location of receptors III Duration of hormone effect on target cell 0 Hormone Pathways I From stimulus to target cell both depend on feedback to regulate III Simple individual cells that make the hormones monitor the change in the body Ex insulin and glucagon 0 2 blood metabolites glucose and Ca2 regulated with little oversight by central nervous system CNS O endocrine cells themselves respond directly to environmental stimulus III Not so simple O CNS controls communication 0 Hypothalamus coordinates between nervous and endocrine systems by monitoring physiological changes 0 Anterior and Posterior pituitaries help the hypothalamus ltgt Posterior extension of hypothalamus Contains axon terminals that release 2 types of hormones These axons are neurosecretorv Hypothalamus Neurosecretory cells of the hypothalamus Neurohormone 7 7 Axons Posterior pituitary Anterior pituitary HORMONE ADH Oxytocln TARGET Kidney Mammary glands tubules uterine muscles 0 Anterior Independent gland that synthesizes and secrets hormones Is controlled by quotreleasing hormonesquot from the hypothalamus Biology Page 3 Neurosecretory cells of the hypothalamus Hypothalamic releasing and a inhibiting hormones Portal vessels Endocrine cells of the anterior pituitary Pituitary hormones Posterior pituitary 0 Tropic Hormones and Axes O Tropic hormones stimulate other glands to release their hormones 0 Ex HPT cascade Hypothalamuspituitarythyroid O Negative feedback in the homeostasis of the system HPT Axle Hypothalamus l Anterior pituitary el Thyroid Increases metabolism 0 Hyper and Hyposecretion 0 Compare to known effect on target cell 0 What function does the hyper or hyposecretion most directly affect and how 0 Hyposecretionhypothryroidism I Myxedema goiter O Hypersecretion I Grave39s disease autoimmune Biology Page 4 Biology Page 5 10122015 Sex Determination Monday October 12 2015 1220 PM IN THE NEWS Why are pregnant women concerned with using plastic containers during pregnancy BPA 0 Estrogen plays a critical role in the development and regulation of female reproduction cycle Effects cf Estrogen Brain helps tp maintain the 39 lacucly temperature BI39EIEISt helps against mempry lpss l 39 Stin39IUlatES the deyelcupment at puberty prepare the glands far future millc prcuducticn Heart and Liver regulates prcducticn pf chplestercl Edecreas the buildup of plaque in the mammary arteries Duary stimulates the maturatipn thEI39LIS stimulates the start at stimulates the maturaticn IIcuman s menstrual cycle helps tc prepare the uterus tcu ncurish a deyelpping fetus 39u39agina stimulates the maturatipn helps maintain a lubricated and thick yaginal lining ivcy unes helps tc preseryer lacne density 0 The default gender in humans is female and estrogen levels can stimulate fatty tissue in breasts in both males and femalesgt Gynecomastia man boobs 0 An endocrine disruptor is a molecule that has a similar shape and charge of a hormone that binds to receptor and trigger biological process that the hormone would trigger BPA mimics the shape and charge ofestrogen endocrine disruptor Figure 6 Source State ofthe Science of Endocrine Disrupting Chemicals 2012 InterOrganization Programme for the Sound Management of Chemicals 0 Study used wild population of birds to measure endocrine disruption because the biological processes involved with estrogen is ancient 0 Bisphenol A BPA was synthesized in 1891 as an estrogen mimic 195039s it became polycarbonate plastics most commonly found in plastic bottles Biology Page 1 0 Sources Receipt paper plastic bottles children39s toys inside of cans sports bottles 0 Effects on children 0 We aren39t exactly sure but at most there would be SOME concern for effects on brain behavior and prostate gland 0 Phytoestrogens O Naturally occurring compounds that happen to have a similar enough shape and charge to elicit hormone effect 0 Soy just because it has phytoestrogens in it does not mean it will elicit estrogenlike effects We don39t know yet 0 Effect on animals 0 Endocrine disrupting chemicals feminize male frogs and cause homosexual behavior 0 There were many more females downstream of urban areas than upstream Why Estrogen in birth control passes through sewage system and into water ways Sex Determination 0 Picture shown of lots of women and a boy What do they have in common They all have an X AND Y chromosome 0 Complete androgen insensitivity syndrome 0 Early In development sex organs are undifferentiated and can develop either male or female I Most cases people go down a certain pathway when signaled by hormone I If not signaled the default sex is female I So people with this condition do produce androgen but the receptors that elicit biological response from androgen are not functional I XX individuals can have defect for androgen sensitivity but they do not express this because they have a good copy on the other X chromosome I XY individuals look like females but are sterile No pubic hair or body odor o Caster Semenya XY individual who had no special advantage athletically even though she has a Y chromosome 0 CAIS is 1 in 100000 0 Australians let people selfidentify their gender as MF or X 0 Klinefelter syndrome 0 XXY syndrome 0 Born male Puberty poor beard growth breast development underdeveloped testes tall narrow facial features wider hips usually infertile Ex Caroline Cossey 0 Chromosomal nondisjunction event that occurred in gamete mother or father 0 Very few nondisjunction events that are nonfatal DownSyndrome on chromosome 21 and sex determination 0 Most KS is determined prenatally also between ages 20 and 40 O Clicker Question Why are most cases of Klinefelter syndrome diagnosed in men between ages 2040 I That is the age when most men discover they are infertile 0 Hermaphrodites 0 Common in animal kingdom I Most mollusks and invertebrates I Marine flatworms engage in competition in which 2 males violently try to impregnate each other Loser raises the eggs I Sequential hermaphroditism in Parrotfish As the individual gets larger they become more malelike Biology Page 2 I la n1 preys I IIF39Etrcirn yzonti jrm E5 Ti I i hEl l ll39l r shes E 1122 G tEtrapudls fEarmpt EwgiiJf iii i harming E eat h Jquot W I t mnrphaj all a I salmon 31 SHIEHZE 21 W1 u IEP rntaca n thoptewg i i 39jl I hatehet sh i I Emmiatirnmes H d39 I la ntErnl sslllm I M39y39Ci pl liF l l Es I trout perches I 1Tb BF ltm kil ht l h EGEI eta l39E tE ifurmasj I PE rm peiforn iesj I may 3 wards 39quotquot Gadif rmeaj 39y if whaigfish ill I W 39 Eit ephannbe rycif rmasj a u J 1 if I tnad slllm quot Ea trachnidif ormesj battens Ema bantif rm any Er sh LEII2Il39Ii ifnrmesjl ice ah ENDtDthEniifUrInesj msitipmudemaau anemone anew 13m a eaum tuna Scnmbri j I39mES l u gr llm 39Tetraod ntif rmESJ Most animals were hermaphroditic until fish came along and started sequential hermaphroditism Clownfish protandry I Stable family dominant female one nondominant male several undifferentiated juveniles I If dominant female dies the nondominant male transforms and becomes dominant female The non differentiated ones can transform and become nondominant male or a different nondominant male fish from another grouping can join Clicker Question Why do most sequential hermaphrodites go from male to female III It39s harder to produce eggs than sperm takes much more energy It39s easier to invest extra energy if you are larger III This changed the fishing policy where we threw back the small fish and kept the large ones because this left the population as mostly males Protandry male to female protogyny female to male III How do species pick transforming to male or female Organisms settle on solution that maximizes their ability to pass on their genes III IndoPacific cleaner wrasse fish protogyny Dominant male maintains a group of females but if something happens to him one of the females will develop into the dominant male within 2 weeks SRY gene is the male determination factor experiment done on mice proves this III DNAbinding protein that is responsible for initiating male sex determination III Marsupials and placentals follow SRY method of determination Biology Page 3 I Monotremes use different sex determination ZW just like in birds and reptiles 11 22 male I ZW female III Z chromosome is larger and has more genes III Ovum determines sex of offspring not sperm like in XY I In mice there are differences in neuronal cells between sexes III Male neuronal cells have more dendritic spines and more microglial cells 0 Biological basis for gender identity 0 We don t know 0 Genes E be identified as gay Researchers looked at groups of identicalfraternal twins with samedifferent sexuality Looked at methylgenetics which affects how gene is expressed 0 Parthenogenesis 0 Virgin birth 0 Offspring develops from unfertilized eggs 0 Occurs in many plants some invertebrates and few vertebrates IHPDW HURHEL FERMLIERMH HHE IFl 39HTHiEIH GIEIH E515 UJIIFFIEH Murnrlall Fertilieatien 1 Freewreer legg eell Three eelle el eeerjed diaritlee in te feur one been m ee egg 4 Belay eherl createl wi cme 3 Egg ie ferritill eecl eet ef eh rem eee mee ll39 FEMEIE Mala with eperm frerri each parent Rear Elhire mee em ee 1 39iil39ir39giiirl Iriirquotl zl39nF Partihenngeneei 1 Freewarer Egg mall Tl39iree Belle d e eerc ed lividere t 4 Belle err1 gerreme eembine wi 39l hire eete ef ile ntieel 3 leIIUJkI EE Elliid di39 ri dEG ghr m gnmggg fr m M33 Banal Imamquot MDEHEL lb ereete EITEIFFE Ez 39U iEt Dr H ugh Hel l39i i Biology Page 4 10142015 Human Microbiome Wednesday ctober 14 2 15 1225 PM Learning Objectives 0 Understand what is meant by the term quothuman microbiome 0 What roles does the microbiome play and how does this contribute to human health 0 What factors can alter an individual s microbiome 0 Microbiome all the microbes in the human body 0 Biofilm community of microbes that live together on a surface 0 Microbes include species from all major domains of life 0 They are ALL over us millions per square inch of body 0 Each thrive in different environments 0 More microbes than cells by 10 fold 0 Most microbes are in intestine 60 of the dry mass of human feces 0 Hotspots on body for microbial life 0 Nose mouth skin gastrointestinal urogenital 0 Nose 0 Primary defender against inhaled pathogens 0 Cilia and mucous lining trap inhaled microbes 0 Inflammation results from viral infection and allergic reactions 0 Common normal microbes found in nasal passage I Staphylococcous epidermidis forms biofilm that coats mucosal lining I Staphylococcus aureus is controlled by a protist but can go out of control and make you sick I Apergillus fungal spores often inhaled If not cleared out mold grows in lungs I Corneybacterium accolens rarely a pathogen but can enter bloodstream from torn blood vessel and cause infection 0 Mouth 0 Saliva pH temp immune system prevent many species from surviving in mouth 0 Symbiosis of oral microbes form scaffold on tooth enamel at interface with gums as a barrier to bad bacteria 0 Normal microbes I Fusobacterium sp helps form scaffold on which other bacteria can attach and help form biofilm I Streptococcus mitis forms biofilm on hard enamel surface of teeth If gums are inflamed it can enter bloodstream and cause infection I Prevotella spp Have natural antibiotic resistance genes Can attach to epithelial cells or other bacteria and cause infection in inflamed areas I Candida albicans fungus commonly known as thrush 0 Skin 0 Environments oily dry moist Bacteria feed on oil dead skin cells organic matter and each other Natural defenses sweat is acidic antimicrobial peptides Damaged skin gives opportunity for microbes to invade bloodstream Natural flora of bacteria on skin is primary defense against pathogens Normal microbes I Propionibacterium acnes colonizes healthy pores but if pores become clogged it grows out of control 0 00000 Biology Page 1 I Staphylococcus epidermidis When P acnes grows out of control S epidermidis also grows out of control in infected pores I Staphyllococcus aures can also infect clogged pores Many antibiotic resistant strains I Trichophyton and Microsporum fungi feed on keratin in skin and give rise to ringworm infections 0 Urogenital tract 0 O 0 Urinary system usually sterile due to urea and other chemicals Escherichia coli from GI tract can infect urinary tract Vagina has low pH due to Lactobacillus secreting lactic acid and hydrogen peroxide gt controls pathogens I If Lactobacillus decreases from antibiotics III Candida albicans can cause yeast infection III Gardenerella vaginais cause vaginosis 0 Birth and Microbiome O O 0 When levels of Iactobacillus drops pH becomes more neutral and risk of infection rises Composition of vaginal microbiome proportion of Lactobacillus and therefore pH linked to race Vaginal microbiome changes during pregnancy bacteria that contribute to an acidic vaginal environment increase to help inhibit STDs Weight gain during pregnancy is associated with Bacterioides excessive gain and Bifidobacterium normal gain Vertical transmission of microbiome to the infant by normal vaginal birth helps boost its immune system 0 Breastfeeding greatly positively impacts microbiome O 0 Gut 0 000000 0 O O I Clostridorium difficile and Bacterioides are more common in formula fed babies Infections of the placenta that induce preterm births seem to relate to bacteria found in oral cavity Barriers to pathogenic microbes low pH saliva and bile immune system finding a place to attach to intestinal wall Healthy flora in gut assist digestion and produce vitamins I Synthesis of Vitamin K biotin folic acid I Harvest nutrients I Renew epithelial cells lining intestinal tract I Development and function of immune system I Locomotion I Cardiac size Gene transfer btwn species in guts can generate new drugresistant super bugs Their genome contains 100x as many genes as our genome Gut microbes distinguish self from other Enriched for methanogenic pathway that releases H2 through methanogenesis Microbes secrete compounds that regulate Tcells cytokines and chemokines Bacteroides thetaiotaomicron bacteria ferments simple carbohydrates in the gut releasing hydrogen and C02 Methanobrevibacter smithii is an arcahaean that consumes hydrogen gas from Bacteroides and produces methane which is lost from gut as gas Ruminococcus sp breaks down cellulose to assist with digestion Helicobacter pylori is known to be major cause of stomach ulcers in some people Microbial genes turn onoff in response to what we do and vise versa 0 Clicker Question What does a healthy human microbiome do 0 0 Produce vitamins Influence metabolism and body weight Biology Page 2 0 Contribute to normal healthy brain function 0 Assists immune system 0 All of the above Identical twins have more similar microbiomes is genetics a link 0 Microbes most strongly affected by genes belong to family Christensenellaceae which was most abundant in lean twins and rare in obese twins 0 Fecal matter from lean humans kept mice lean Fecal matter from obese twins made mice obese 0 When lean fecal matter was transplanted mice remained lean even if Christensenellaceae was transferred as well Our microbiome changes through our life 0 Age puberty diet medical conditions medication pets etc 0 You see variation in kinds of microbes number of species number of each species ratio of species relative to each other and kinds of active microbial genes Microbial cloud 0 You are surrounded by cloud and is unique to you It is easily stirred up 0 This will help research in contagious disease and forensics MicrobiomeBrain Connection 0 Relation between stress and microbiome O Bacteria can activate neural pathways and signaling systems 0 Could be used to help cure mental illness 0 Microbiome affects behavior and mood Unhealthy diet is linked to depressive disorders Antibiotics 0 If overused can result in infections 0 Gut flora have modified action of some drugs during metabolism Does this cause different side effects in people 0 Clicker Question What are doctors telling you to do to help restore a damaged microbiome I Change your diet I Consume Probiotic pills I Eat fermented and cultured foods I Have someone else39s poo introduced into your intestine fecal transplant C diff Clostridium difficile is major cause of antibiotic induced colitis and diarrhea 0 Use of antibiotics can kills gut microbiota and allows C diff to flourish bc its resistant to antibiotics 0 As C diff overgrow they release toxins that line intestine causing Cdiff colitis O Cdiff infection most likely to infect patients in hospitals 0 Fecal transplant from a healthy donor restored healthy microbiome in intestine in 14 days Clicker Question How can you maintain your ideal microbiome 0 Eat diverse diet 0 Avoid antibiotics 0 Avoid deodorants and antibiotic soaps O Consume foods with active cultures Scientists think the composition of your microbiome explain differences in metabolic rates and weight tendencies 0 Does diet allow proper microbes that help you stay lean or the other way around 0 Diet and nutrition are the most effective way to improve health I After a McDonalds diet the healthy bacteria numbers plummeted and altered microbial gene expression 0 Diet Biology Page 3 0 High in fresh vegetables fruits little refined food less red meat lots of whole grains lots of cultured and fermented foods 0 Avoid unnecessary use of antibiotics 0 Microbiome may be related to many diseases Biology Page 4 10162015 Population Genetics Friday ctober 16 2015 1231 PM IN THE NEWS Biology of original North Americans Theories of how people came here 0 Crossed land bridge that existed between Siberia and Alaska V ca 23 KYA 39 N I U l r Aleutian ATHABASCANS amp NORTHERN AMERINDIANS islands 39 gquot o 47 7 Genefiow SOUTHERN l ullQQliO WB v39e l l AMERINDIANS 0 Coastal migration from Asia 0 Soultrean hypothesis people were able to cross the Atlantic somehow o Haplotype Q has 17 distinct single nucleotide polymorphisms SNP39s and is common in populations of Native Americans as well as Ket and Selkup people of Siberia o Ancestral Americans did originate from east Asia and further diversified once reaching America By 14000 years ago the majority of the population that would colonize N America had crossed land bridge 0 Inuit have a genetically distinct subgroup of people They migrated to N America about 500 years ago and stayed in Alaska Canada and Greenland 0 Kennewick man looks Caucasian His genetics reveal he is closest relative to Native Americans 0 Anzick boy has genetics related to people of South America YRl Red dashed arrows indicate gene flow 1 of Asianrelated ancestry with tribes of the Pacific Northwest and 2 between Colville and neighboring tribes Kennewick Anzick1 CHB North Paci c Colville CentralSouth America Northwest America Biology Page 1 0 Lord Jeffrey Amherst purposely provided smallpox infected blankets to Native Americans who had no natural immunity to the virus First biological warfare 0 Female population of Native Americans were rapidly reduced upon contact with Europeans due to smallpox and other diseases I Population bottleneck rapid decline of population that results in drastic decline in genetic diversity due to specific gene selection of favorable traits I Founder effect loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population Clicker Question What factor has led to a genetic bottleneck for Native Americans 0 Native Americans were susceptible to European diseases Population Genetics Learning Objectives What is population genetics What are the five evolutionary factors How do these five factors shape the genetic composition of populations and thus evolution What is HardyWeinberg equilibrium and why is it useful How do you use neutral genetic markers to examine evolutionary processes Study of evolutionary changes within a species microevolution o Allele frequencies 0 Genotype frequencies 0 Phenotype frequencies Neutral molecular markers are used to study pop Genetics 0 mDNAno recombination passed down through mother Chloroplast DNA no recombination usually maternal inheritance Microsatellites tandem repeats of DNA sequence ATCATCATCATCATC Single Nucleotide Polymorphisms Allozymes variations of proteins RFLPs variants in DNA exposed by cutting with restriction enzymes 0 AFLPs after digest with restriction enzymes fragments are selected for PCR amplification Clicker Question What do we mean by a region that is neutral 0 Sequence in genome that is not expressed o A sequence region that produces no phenotype Phenotype observable characteristic that results from interaction of genotype with environment Allele frequency how common the allele is in a population Genotype Frequency percent of population that expresses each form of a genotype Dominant allele allele that will always express when present Recessive allele only expressed when paired with another recessive allele Codominant alleles alleles are equally strong and both are present the heterozygote has a blending phenotype Gene pool all alleles of all members of a population 0 Population localized group of individuals that could potentially interbreed Evolutionary factors that cause allele and genotype frequencies to change 1 Mutation change in DNA sequence that introduces variation 2 Gene Flow movement of genes between populations I Movement of individuals seeds pollen spores I Increases variation and homogenizes populations across a landscape 3 Selection variation in fitness heritable Causes nonrandom changes in allele frequencies to reduce variation OOOOO Biology Page 2 I Stronger the selective pressures greater reduction in genetic variation 4 Nonrandom mating quotchoosingquot mates rather than by pure chance 5 Genetic Drift random changes in allele frequencies Happens quickly and is more likely in small populations Random changes in allele frequencies will change between generations andor some alleles will go extinct Loss of variation within a population HardyWeinberg Equilibrium p 12 Where p the frequency of allele A q the frequency of allele a p2 the frequency of individual AA q2 the frequency of individual aa 2pq the frequency of individual Aa p22pqq21 o Allele and genotype frequencies in a population will remain constant from one generation to the next in the absence of evolutionary influences O 5 conditions must be met 1 Large Population size to minimize effects of genetic drift i Genetic drift is fluctuation in allele frequencies by chance but large populations are more resistant to changes than small populations ii 3 types of Genetic drift 1 Strict Sense occurs in small populations that are always small Populations become fixed for one allele or the other 2 Founder Effect small number of colonists leave population and start a new small population with a different allele frequency than the original population 3 Genetic Bottlenecks population is reduced greatly in size Ex disease or disaster American Chestnut 2 No gene flow no emigration or immigration 3 No mutations no new alleles added to gene pool i In humans while the rate of mutations is incredibly small we have so many nucleotides that there are significant numbers of mutation 4 Completely random mating 5 No natural selection all traits contribute equally to survival 0 How is Hardy Weinberg met if there are so many conditions 0 HW never occurs in nature but it provides baseline on which you can compare populations It39s a null hypothesis 0 Test to see how much population deviates from equilibrium 0 One generation of random mating or one generation of mutation may push a pop back to HWE Simple vs Polygenic Traits 0 Simple I Traits controlled by single gene Ex flower color 0 Polygenic Quantitative I Traits controlled by many genes Ex height in humans Stabilizing selection moves towards average Directional Selection moves one way or the other Disruptive Selection when individuals at both extremes have high fitness 0 Clicker Question What is the allele and genotype frequency of a population of 100 people in which 50 have brown eyes and 50 have blue eyes The source population contained 75 brown and 25 blue Biology Page 3 Allelle frequencies 50 people 4 bb 4 50 x 2 100 b 50 x 13 6 BB 6 1666 X 2 333 B x 23 4 Bb g 3333 X 1 333 B g 3333 X 1 1 333 b 1 239 Genotype ratio BB 1 50 x 13 iBb 50 x 23 bb 50 BB 1 Bb bb 17 1 33 50 0 Clicker Question Now that the population has grown from 100 to 10000 and is in HWE what is the ratio of alleles 0 Still 12 because under HWE allele frequencies do not change 0 Clicker Question What is the ratio of genotypes O 144 We assume no evolutionary forces acting on the population thus population is in HWE iNow simply convert the allele ratio to frequencies So 1 2 becomes 13 1 23 iihen plug these frequencies into the HWE eqiuation above with p 13 and q 23 because after a period of random mating the phenotype and genotype frequencies reach eqiuiilibrium as folilows p2 M cl2 132 21323 232 1 011 044 044 144 0 Clicker Question What is the ratio of phenotypes 0 54 since BB 1 and Bb 4 produce brown eyes and bb4 produce blue eyes 0 Clicker Question After only people with brown eyes remain what is the ratio of alleles 0 32 because From the previous scenario we know that the ratio of BB Bb is 1 4 Therefore 15 of people are BB and 45 are Bb BB Bb Now simply count these up to get Bb 6 B and 4 b Bb Bb 0 Clicker Question After the people who remain with brown eyes have one generation of reproduction what is the ratio of genotypes 39 Q 34 it1 Biology Page 4 2H1 23QI2gl Jr IL1 VIiIZ39Lf Phenotype Frequency 214 0 Clicker Question The blue eyed children are once again sacrificed What is the new ratio of alleles I If lt E LI 5 39 Zg blo LI 34 lo UV Io 0 Clicker Question Blue eyes children are no longer going to be sacrificed What are the allele frequencies after 2 more generations 0 Still 52 because the allele frequencies do not change under HWE 0 Clicker Question After 2 generations of all brown eyed adults being sacrificed what is the O Allele frequency 01 0 Genotype Frequency 01 h b m 0 Va 3 0 H4 8 o Phenotype Frequency 01 0 Inbreeding 0 Captain Bligh and crew were thrown off their ship under mutiny but founded Pitcairn island with wives they picked up in Tahiti 0 Today Pitcairn island is inhabited by 67 people and they are all directly related to Captain Bligh O Founder Effect Inbreeding exposes recessive alleles which cannot be removed by natural selection Take home points 1 In the absence of evolutionary changes mutation gene flow nonrandom mating genetic drift amp selection allele frequencies will remain unchanged even if genotype amp phenotype frequencies do change 2 Populations that go through a genetic bottleneck or strong selection can quickly have their allele frequencies altered from that of the parent population 3 Even in the face of strong selection against the homozygous recessive condition a recessive allele can remain in the population forever 4 If the selection against the homozygous recessive is removed HardyWeinberg equilibrium is reached again in one generation although original allele frequencies are altered 5 If selection acts against the dominant allele it is quickly eliminated from the population 6 Inbred populations do not do well over time Biology Page 5 102315 Evolution Monday October 19 2015 1222 PM IN THE NEWS Who s your great 40000 y o grandpa from Johannesburg South Africa 0 Homo naledi O 0000 0 Found in the back chamber of a cave in South Africa along with 15 other bodies from babies to elderly Skull shape similar to early Homo species Possibly the earliest branch of our lineage There were 5 or 6 different hominid species living in that part of Africa In order to get their bones way back into that chamber they had to be carried by someone I Evidence of intentional burial This is the first time this species has been identified 0 Guest speaker Hannah Morris O 0000 Brain was a little smaller than ours about the size of orange Shoulder and trunk are more primitive Fingers are long and curved more like Australopithecus Feet are just a tiny bit flatter Overall they are very similar to us Evolution Learning Objectives What is a chromosome What is a karyotype What produces a banding pattern on chromosomes How can a karyotype be used to make comparisons between different taxa How does a karyotype compare to gene sequencing 0 Clicker Question Who was the first person to suggest that humans and the other great apes be grouped together 0 Carolus Linnaeus I Swedish naturalist who categorized all living things today I Defined our genus originally as Homo diurnis man of the day and homo nocturnus man of the night orangutans SO he included the orangutan in with the same group as humans I Gorillas weren39t included because Westerners didn39t know about gorillas I He knew grouping primates and humans would cause controversy but didn39t know any reason for separating them I 100 years later in 1850 Charles Darwin published the Origin of Species I All the theologians went against Darwin for his idea of evolution 0 Clicker Question What is the primary reason that some people have difficulty accepting that humans and the other great apes share a common ancestor O RELIGION Biology Page 1 Humans and chimpanzees are almost 99 identical genetically 0 They also have nearly identical muscle groups and even an appendix 1871 Charles Darwin wrote The Descent of Man that acknowledged similarity between humans and many other apes 0 Claim based on comparative anatomy 0 Behavior of animal had humanlike interactions 0 They have the same types of behaviors and emotions that we do kindness jealousy laughter mourning rage empathy Lucy O Australopithecus afarensis 0 Found in Ethiopia 32 mya 0 Adult female quot25 yo 0 Bipedal walked on 2 feet like us Clicker Question How did scientists do comparative genetics before DNA sequencing was invented in the 19703 0 By looking directly at genes under a microscope WaldeyerHartz and others used a staining technique that allowed him to visualize chromosomes in cells that were about to undergo division so at metaphase 0 Used Hematoxylin a compound extracted from the heartwood of the logwood tree to stain I Giemsa stain is used in quotGbandingquot to stain chromosomes because it attaches itself to AT regions of DNA well 0 Created karyotype number and appearance of chromosomes in nucleus of eukaryotic cell 0 Humans 22 pairs of autosomal chromosomes and 1 pair of sex chromosomes 0 Chromosome banding technique shows bands that distinguish between species or compare genes within a species I Focus on length the position of the centromeres banding pattern and any other physical characteristics 0 Karyotyping still used in invitro fertilization clinics because it quickly spots trisomy events and broken chromosomes that broke during crossing over O Karyotypes can also be used to construct phylogenies Biology Page 2 Ka ryotype Banded chromosome Dark bands are A T or G C rich 3 K H i ii 35 1832971713 6 1o 11 12 0 u 3i 5 n 13 14 1s 16 17 18 quot 8 4 1 19 20 21 2 Biology Page 3 10262015 Human Evolution Monday ctober 26 2615 1156 AM Learning Objectives What is meant by the term hominid What evidence supports the idea that humans and the other great apes chimps bonobos gorillas orangutans all share a common ancestor In what ways can genetics inform us about the course of human evolution In terms of chromosomal similarity Humangt chimpgt gorillagt orangutan Humans do not have 2 functional centromeres on chromosome 2 like the chimps gorillas and orangutans do because humans have 46 chromosomes 23 pairs and all the other great apes have 48 24 pairs WHY o The ancestor of all the great apes had 48 and it39s been reduced in humans to 46 l i l1 Upl 39 E Much more likely Much less feaSIble Human 5 Human 451 E mmun Common grungestar E n ib H13 anteninr H39 nuh HE 45139 E hi mpa name 43 Chimpanzee 43 Gunilla ME Gunilla 4E Chromosome number Hiramme number reduction event increase we t o How could an entire chromosome be lost We didn39t lose it We fused chromosomes I Telomeres fused together but no DNA was lost bc telomeres do not code for proteins I All genes found on human chromosome 2 match up to 2 separate chromosomes that the great apes have We have found the hidden fused telomeres and the centromere within human chromosome 2gt that39s why we only have one centromere on chromosome 2 Biology Page 1 4 6 million years ago 6 8 million years ago 12 romnlron years ago 0 What other evidence is there for establishing a relationship between humans and the great apes Chimpanzee Ancient Hominid Human Fan Trogldd es Australopithews afarensis Homo Sapient FiquFE 159 W V Some skeletal iea lur ES ll an aus 39 r 3 T g b tralotil thetlru are r11 r rm 1 all in between thaw Ell ri l t j mes and lmn rans ramparta the skull and jzwlxrin horr of Airs lr l r ijiither E i lll39um a ElfENVELP39iitn Ell Wit h thle tin thirdl Araratblur Atel abulum l pumice iii and 7 Elle humane Elk 39 I J H a l schial ilS39cliial ischial tuberosity39 tuberosity tuber355W 0 Fossil similarities between modern humans ancient hominids and chimps o Genome sequence of chimpanzee is incredibly close to humans 0 The molecular clock suggests that certain genes will mutate at a rate of nucleotide change based on the organism We use radiometric dated fossil evidence to calibrate this quotclockquot This estimates how long ago one organism shared a common ancestor with another 0 ERV39s stay in genomes once incorporated They are inherited and accumulate We can identify ERV39s and say with certainty that chimps and humans share a common ancestor around 5 mya 0 Similar pathogens infect both chimps and humans HIV was transmitted to humans through contact Biology Page 2 O with chimps in Cameroon One strain of malaria can also affect us both Don39t look for what they have in common but how they differ 0 Guinea pigs apes some fruit bats and humans cannot make their own ascorbic acid Vit C but all other mammals can 0 O O In humans and apes the inability to make Vitamin C is due to a defective gene that no longer codes for an enzyme LGULO essential to making Vit C known as pseudogene LGULOP We have specific nucleotide changes that have rendered this gene nonfunctional same changes are present in chimps gorillas orangutan and macaque So humans and apes must be descended from a common ancestor that had that error pseudogene Consequences of no Vit C Scurvy I Clicker Question Why don39t humans and the great apes get scurvy if we don39t make Vitamin C 0 We get enough from our diets FRUIT I Parasites are another way to make evolutionary comparisons O O 0 Head lice and body lice appear to be different but genetically are determined to be the same species Claws on body lice are hooked but those of head lice are not This is so they can grab clothes Body lice are a strain that has evolved from the head licegt we can estimate this species divergence back to when humans started wearing clothes 4070000 years ago Body lice adapted to new environment and gained claws to be more successful in latching onto clothes Study of pubic lice suggests that human pubic lice are more closely related to gorilla pubic lice than chimps This means ancient humans were fooling around with gorillas But no progeny resulted because we have different numbers of chromosomes I Clicker Question What distinguishes our species Homo Sapiens from all other primates that have ever existed and from the other great apes 0 There really is nothing that distinguishes us from other primates I Human Evolution 0 O O O O Ardipithecus ramidus is a 44 mya skeleton found in Ethiopia I Bipedal I Upright but she did have a grasping toe She was probably standing up in trees I Teeth are between chimps and homo sapiens I Filled gap between chimps and australopithecines Lucy and her Australopithecus relatives used simple tools Homo habilis arose 25 mya and used tools Footprint of Homo ergaster found in Africa exhibits the same locomotion as we do Homo erectus arose 16 mya in Africa Used tools and fire Walked out of Africa Modern Homo sapiens evolved in Africa and migrated out of Africa 100000 yea rs ago EVOLUTIONARY ORDER oldest to most recent Arrlinifhort 1c rnmirl 1c Aucfrnlnnifhor 1c lInmn hnhilic lInmn ornncfor lInmn ororh 1c Biology Page 3 EVOLUTIONARY ORDER oldest to most recent Ardipithecus ramidus gt Australopithecus gt Homo habilis gt Homo ergoster gt Homo erectus gt Homo sapiens J HOMINID EVOLUTION I i saw Gene sequence from 2 teeth and 1 finger bone found in cave Denisovan Shows it is very different from both humans and Neanderthals according to mDNA Melanesians and Tibetans today still have Denisovan genes the different hemoglobin genes I A five nucleotide haplotype AGGAA is known only from Tibetans and Denisovans I This allele may allow Tibetans to live in a reduced oxygen atmosphere with the same amount of hemoglobin Hb as North Americans living at sea level whereas South Americans need more Hb Neanderthals We interbred with Neanderthals and Denisovans Modern humans that are not of direct African descent have 14 Neanderthal genes Biology Page 4 I Could Neanderthals speak Yes There is a gene that is essential for verbal communication Neanderthals had it I They also had developed family and clan structures and practiced intentional burials I They diverged from H Sapiens about 500000 years ago Biology Page 5 1122015 Biology of Human Race Monday November 2 2015 1218 PM IN THE NEWS Who39s afraid of the big bad coywolf 0 There is an area of sympatry between wolf and coyote in Texas between Western gray wolf and western coyote 0 The wolf and coyote are able to interbreed but are the offspring fertile We don39t know yet 0 In Massachusetts mDNA was analyzed and found that there is hybridization between the eastern coyote and wolf 0 Coywolf DNA mostly coyote 110th dog 14th wolf 0 Explanation There was lots of forest clearing and active hunting of wolves gt coyotes moved out of prairies and into this region Wolves had few reproductive options so they started breeding with coyotes and sometimes dogs 0 Usually hybridization is not successful but the coywolf is It is larger faster stronger and has behavioral adaptations suitable to both the environments and diets of both wolves and coyotes Very adaptable 0 Is this a new species How do we classify it Learning Objectives 0 What is meant by the term race 0 What evidence supports the idea that different races of humans exist and what are the criteria by which these races are distinguished from one another 0 What factors can lead to genetic separation of human races What factors serve to eliminate those separations 0 What factors led to different levels of skin pigmentation in humans Race person39s physical characteristics skin hair eye color Genetic diversity among subpopulations of humans Ethnicity cultural factors nationality traditions religion 0 First classification of race 0 Johann Blumenbach quot1800 divided species into 5 races white yellow brown black red 0 Skin color and cranial features 0 Linnaeus divided races into European Asian African and Native American 0 Clicker Question differences in human races are 0 Genetic 0 There are amp fixed genetic differences for race 0 Mitochondrial Eve the woman from whom all living humans are descended is believed to have lived 140000 years ago in East Africa 0 Ychromosomal Adam lived in Africa around 60000 years ago and is the closest relative of all living men 0 Possible bottleneck quot70000 years ago from eruption of super volcano reduced population to 10000 0 People in Africa have greatest genetic diversity of all humans 0 A gene associated with crossing over is much more highly expressed in the genome of Africans 0 Lots more crossing over and recombination occurs in African lineages than others 0 Humanity is moving towards elimination of all races 0 Air travel and social norms increase interracial marriages 0 All humans can trace their ancestry back to Africa 0 Clicker Question What is the evolutionary pressure that led to dark pigmented skin in humans I Dark skin helps prevent against birth defects 0 Human skin color correlates with UV levels 0 Darker skin is more prevalent close to the equator and at high altitude 0 UV radiation destroys folic acid which is an important component in preventing neural tube birth defects 0 So if dark skin maintains folic acid levels why has fair skin been selected for in some races Biology Page 1 I Vitamin D can be synthesized in people with fair skin better than in people with dark skin I MCIR gene is located on the surface of melanocytes which produce melanin Among people of Africa there are only 3 alleles for the MCIR gene which continue to select for dark skin III Red hair is usually result of mutation in MCIR gene Red heads can metabolize anesthetics at a higher rate and may require up to 20 more anesthesia More prone to develop melanoma 0 Color blindness is most commonly inherited from mutations on the X chromosome but 19 other chromosomes can cause the mutation as well 0 TaySachs is a fatal genetic lipid storage disorder in which harmful quantities of a fatty substance called ganglioside GMZ build up in tissues and nerve cells Autosomal recessive disorder manifested in homozygous carriers of both recessive alleles Affects children and most die before age 5 Most prevalent in Ashkenazi Jewish population 0 Over time the allele frequency of the recessive TaySachs allele decreases because this lethal allele kills individuals before reaching sexually reproductive age 0 Dor Yashorem genetically tests young people in Orthodox Ashkenazi Jewish communities to screen for diseases and advise or not advise couples to get married and have kids I Blood test that measures betahexosaminidase activity 0 Is this eugenics 0 Bottom line Our racial diversity affects our genetics and biology Biology Page 2 114 6 and 92015 Speciation and Biodiversity Wednesday November 4 ZQIS 1232 PM Learning Objectives Understand the difference between anagenesis and cladogenesis Understand the 4 modes of speciation in terms of geographic origin Understand the 4 modes of speciation as classifed by genetic causation For sympatric speciation be able to describe the isolating mechanisms responsible for prezygotic and post zygotic reproductive isolation Clicker Question What is the most important factor that holds a gene pool of a species together and prevents speciation 0 Gene flow Macroevolution origin of new taxonomic groups species genera families etc Speciation is the bridge between microevolution and macroevolution 0 Origin of new species 0 Can be gradual or rapid but is too rapid to be welldocumented in the fossil record Patterns of speciation o Anagenesis aka phyletic evolution accumulation of microevolutionary changes that result in the earlier population being considered a separate species from the later population 0 Cladogenesis aka branching evolution Over time you have several species resulting from a parent species The formation of a new branch is a macroevolutionary effect I Describes origin of biodiversity Reproductive isolation 0 Through reproductive isolation organisms within one group will be more closely related to one another than to organisms outside that group 0 Speciation is the outcome of reproductive isolation over time Clicker Question What evolutionary factors are responsible for genetic divergence among populations 0 Mutation genetic drift and selection Modes of Speciation are 0 classified by geographic origin of reproductive barriers I Allopatric speciation Reproductive barrier resulting from a geographic barrier This happens in 2 ways ii Vicariance divergence of 2 large populations ex volcano ii Peripatric speciation divergence of small population from the larger ancestral population ex colonizing of an island I Parapatric speciation neighboring populations between which have a small amount of gene flow diverge and become reproductively isolated I Sympatric speciation evolution of reproductive barriers within a single initially random mating pop 0 Classified by genetic and causal basis Biology Page 1 Genetic divergence allele substitution III Genetic drift III Natural selection Cytoplasmic incompatibility Cytological divergence III Polyploidy III Chromosomal rearrangement Recombinational speciation 0 Allopatric speciation reproductive barriers that result from geographic isolation 0 Ex continental drift isthmus of Panama mountain range formations canyons rivers 0 By Vicariance Grand canyon split a population of ancestral squirrels into 2 species bc they were separated by canyon o By Peripatry Some of the population separates from the majority of the parent population and then diverges into a separate species I Leads to Adaptive Radiation organisms diversify to fill different niches III Ex Darwin39s finches Key innovation is some variable trait that can allow access to a niche beak shape 0 Parapatric Speciation 0 Ex ancestral species of salamander was in WA but some migrated As they migrated southward habitats varied Adiacent populations could interbreed but more distant populations could not RING SPECIES 0 Sympatric speciation genetic isolation and divergence occurs despite lack of geographic barrier 0 Ex white mice are less visible out in the field than in the low lit forest So mice that live in forest become darker in fur color 0 Ex Cichlid fish in different African lakes 0 Ex feed same species of fruit flies and feed them different food sources When they reunite the flies who lived off the same food source were more likely to mate POSITIVE ASSORTATIVE MATING like mates with like I Test for positive assortative mating character displacement Describes characters that are more divergent in populations that live sympatrically than in allopatric populations 0 Sympatric Reproductive Isolation I Prezygotic isolation potential mates never meet possibly due to III behavior differences mating signals color differences III temporal isolation nocturnaldiurnal seasonal cycles III mechanical isolation cannot physically reproduce bc the sexual organs are incompatible III Gametic mortality gametes fail if not implanted into the proper species ex pollen I Postzygotic isolation III Zygote mortality forms but dies soon after fertilization Hybrid inviability hybrid dies during development Hybrid sterility hybrid survives but can39t reproduce Ex F horse M donkey sterile mule Low hybrid fitness hybrid survives but is not very successful EDD 0 Cryptic species different species with nearly identical morphology that usually live in the same habitat They are reproductively isolated based on different behaviors 0 Clicker Question What is the best explanation for the presence of 12 subspecies of the giant tortoise endemic to the Galapagos islands Biology Page 2 0 One colonization from a small tortoise from South America gave rise to the 12 giants of Galapagos 0 Sexual Selection Female mate choice is important cause of speciation 0 To test if sexual selection influences speciation compare species diversity of sister groups to see if sexual selection is related to increased species diversity 0 Modes of Abrupt Speciation o Polyploidy failure of cell division that fails to separate chromosomes into 2 cells Lead to accidental formation of something other than a diploid organism Organism is more likely to succeed if it has an even ploidy Most common in plants I Ex Wheat is doubly allopolyploid 6N III 3 different parental species 0 Hybridization progeny of hybridization has characteristics that allow it to take advantage of a different niche and may become isolated from the parental forms 0 Chromosomal rearrangement inversion that reproductively isolates these individuals I Often in small populations subject to severe stress Two breaks in a single chromosome cause inversion deletion or ring structure AKA saltation diversification o Recombinational speciation F1 hybrids produce a great variety of recombinant offspring some of which may be fertile but reproductively isolated from the 2 parent species Very common in plants not common in animals Ex sunflowers 0 Tempo of evolution 0 Coelcanth is the link between fish and 4 legged animal Related to lungfishes and tetrapods Thought to have been extinct for 65 million years 0 However the species was found off the coast of South Africa in 1938 Lazarus taxon thought to have been dead but we found it 0 View 1 Evolution is gradual and slow 0 View 2 Punctuated equilibrium something that very suddenly gives rise to new species 0 Both views are right 0 Clicker Question Which of the following statements best describes when evolution has occurred 0 A population has a different allele frequency in this generation compared to the last generation 0 Species Concept 0 What are the essential attributes of a species that define it o 2 meanings of species I quotFamilyquot used to classify plants I quotRelatednessquot describes evolutionary relatedness Goals in classifying species 0 1 to enable us to classify organisms systematically 2 that a species corresponds to discrete groups of similar closely related organisms 3 to help us understand how these discrete clusters of organisms arise in nature 4 to represent products of evolutionary history andor 5 to apply to the largest possible variety of organisms Species is the smallest independent unit of evolution All modern species fall under a lineage concept At least 23 different species concepts The essence of speciation is the lack of gene flow Species are distinct bc they don39t have gene flow with each other 0000 Biology Page 3 0 Species Concepts Examples 0 Typological a species is a group whose members share certain characteristics that distinguish them from other species I Conformed members of a species to a quottypequot I Essentialist notion there is an ideal form that is imperfectly imitated by other earthly forms I The type specimen defines the species I Doesn t work with evolutionary change I Who gets to decide what the ideal type is Clicker Question What is the fundamental problem with the typological species concept III The type specimen may not represent the whole species III Morphological variation exists within a species III Speciation is an ongoing process 0 Darwin states that species is an artificial categorization for our convenience I Qualitativer there is no difference between varieties and species it is just a continuum I He states that varieties are connected present day and species were connected in the past 0 Morphological species is a group of organisms with similar anatomical characteristics I Preferred for plants and asexually reproducing organisms I Problems III sometimes morphological criteria are arbitrary III What about sympatric species They live in the same location and are very similar but are different lineages III Cryptic species have different genes but are phenotypically very similar III What about sexual dimorphism morphology changes at different stages of life 0 Biological species is defined as naturally occurring groups of individuals that actually or can potentially interbreed and produce viable offspring I Involves development of reproductive barriers and isolation I First concept to emphasize the process by which species arise I Can only be used on contemporary populations Inferences cannot be drawn over a time span I Difficult to apply this concept to hybrid species Ex Lonicera fly Pomarine skua Mariana mallard I Only applies to sexually reproducing organisms What about asexual Parthenogenic I How can you apply this to bacteria which can change their genome I Despite the problems this concept is applicable to many species and is the most used concept Biology Page 4 119 and 11 2015 Ecology Biosphere and Abiotic Conditions Monday November 9 2 15 1214 PM IN THE NEWS How will the change in China39s One Child policy affect the world population in 2030 Chinese population growth has been decreasing There is growing elderly retired group but a shrinking workforce that will be unable to support them 0 The world population growth rate is expected to decrease as well due to the large influence of China39s population The onechild rule has been relaxed over the last few years because they realized their population size was not sustainable based on the resources available The global population is nearing the carrying capacity of the Earth it39s possible a large epidemic or disaster will occur to lessen global population It is estimated that 2 billion people is the carrying capacity of Earth We have been exceeding carrying capacity since 192039s The result is inevitable resource overexploitation Learning Objectives Understand why we study organisms in relation to their environments Understand the influence of abiotic conditions on the distribution of species Consider similarities and differences among terrestrial and aquatic biomes Ecology study of our home Biomes areas of the planet characterized by similar plant communities A largescale type ecosystem that is representative of a climate type and region Ex tropical rainforest desert tundra o Vary in the average seasonal pattern 0 Influenced by precipitation and temperature Holdridge Life Zone more advanced classification of biomes 0 If you know the climate you can map the soil type and climax vegetation 0 Put in terms of humidity aridity mean annual temp and avg annual precipitation 0 Found 36 biome classifications influenced by altitude and latitude Extremes vs Means o A species cannot survive outside its tolerance range I Ex San Francisco and Kansas City have the same avg temp but San Fran ranges 3590 and Kansas City ranges 5 to 105 Organisms endure much greater extremes in Kansas City 0 An organism must survive all stages of life cycle Climate vs Weather 0 Weather shortterm and localized 0 Climate avg weather conditions in a region over a long period of time 0 Clicker Question which of these incudes all the others in creating global terrestrial climates I Earth39s rotation on its axis I Differential heating of Earth39s surface I Global wind patterns I Ocean currents I Evaporation of water from ocean surface 0 Factors affecting Earth39s climate Biology Page 1 1 solar radiation 2 Earth39s position relative to sun tilt rotation revolution 3 Atmospheric gasses 4 Global air circulation i North Atlantic circulation driven by warm salty water moving northward where it cools sinks down then flows south gt Gulf Stream ii Global Conveyor Belt connects all the major currents 5 Global ocean currents i Gulf Stream is slowing down because the melting freshwater Greenland ce sheet is preventing denser salt water from sinking and cooling gt This is causing UK and Northern Europe to become colder because the warm stream won39t reach Europe ii Slowing of Gulf Stream will cause corals in Bermuda to die because the water will get too cold to support them Existing reefs will fail and Bermuda will no longer be shielded from tropical storms O Milankovitch Cycles Earth39s movement around the sun that influence seasonality I ccentricity how elliptical or circular the rotation of Earth is around the sun III Affect glaciation periods by altering the distance solar radiation has to travel III Changes every 100000 years III Currently we are in low eccentricity close to circular I Axial tilt aka obliquity inclination of Earth39s axis III Affects seasons hemisphere tilted toward sun gets more sunlightday III Angle varies between 215 and 245 I Precession change in the direction of the Earth39s axis of rotation relative to the fixed stars Earth39s slow wobble as it spins on axis III Periodicity 23000 years III Perihelion point on its orbit when the Earth is closest to the sun III Aphelion point on its orbit when Earth is farthest from the sun III m 11000 years our seasons will switch times during the year and seasons will be more severe 0 Research argues that forests are rainmakers O Biotic Pump Hypothesis natural forests create and control oceantoland winds bringing moisture to land I When water condenses it creates a low pressure zone because there are suddenly many less gas molecules This drives wind that creates rainfall Biology Page 2 1111 13 162015 Population Ecology Wednesday November 11 2015 1252 PM Learning Objectives Describe how lifetables and survivorship curves represent populations over time Describe tradeoffs between survival and reproduction life history traits Relate population growth to organisms environments abiotic and biotic Population Ecology study of populations in relation to their environment 0 Births 0 Deaths 0 Immigration 0 Emigration Population density number of individuals per unit of area Population dispersion Spacing of individuals in a population 0 Clumped fungi and plants insects salamanders schools of fish flocks of birds 0 Uniform much less common Penguins 0 Random Windblown dandelion seeds Population Monitoring 0 Mark and Recapture xn sN I 5 number of animals caught during first sampling I n number of animals caught during second sampling I X number of animals caught in second sampling that were already marked I N estimated total size of population 0 Demography study of vital statistics of populations and how they change over time Usually deals with birth and death rates 0 Lifetables agespecific summaries of survival table 53 Life Table for Belding s Ground Squirrels Spermophllus beldingi at Tioga Pass in the Sierra Nevada of Californiaquot FEMALES MALES Number Average Number Average Number Proportion of Additional Number Proportion of Additional Alive at Alive at Deaths Life Alive at Alive Deaths Life Age Start of Start of During Death Expectancy Start of at Start During Death Expectancy years Year Year Year Ratet years Year of Year Year Rate39 years 0 1 337 1000 207 061 133 349 1000 227 065 107 12 2521 0386 125 050 156 248t 0350 140 056 112 2 3 127 0197 60 047 160 108 0152 74 069 093 3 4 67 0106 32 048 159 34 0048 23 068 089 4 5 35 0054 16 046 159 11 0015 9 082 068 5 6 19 0029 10 053 150 2 0003 2 100 050 67 9 0014 4 044 161 0 Biology Page 1 O Survivorship curves graphical representations of life tables that show how long various age groups live 1000 lt 100 10 Number of survivors log scale I Type 1 large mammals with few offspring and provide extensive child care I Type 2 moderate number of offspring some care Many lizards some rodents and invertebrates I Type 3 very large number of offspring no care Fish most invertebrates and insects Number of survivors log scale Percentage of maximum life span 0 Clicker Question Why do humans have a longer survivorship curve than squirrels and oysters Humans have fewer offspring than squirrels or oysters 0 Formula for growthyr of kids 22 x avg birth age x 100 0 Reproductive tables fertility schedules measure reproduction of a cohort for the life span of the cohort Records of female offspring produced by each age group cohort Biology Page 2 table 522 Reproductive table for Belding s Ground Squirrels at 1093 Pass Moan Mean Proportion Size of Number Avomgc of females Liners 0 humor Age Wrnmng Mules Female of FMquot Ne years a uttcv lemoch 391 a Line U sptznq39 l l 0 l quotn n 39 I I 3 ll U gt3 1 l l gt3 Val 4 3 gt 7 y M sly Table 522 0 Growth curves 0 Exponential each generation doubles in size Often results in environmental degradation 0 Logistic Population expands more slowly as it reaches its carrying capacity Realistic model dNdt rN1 lquotpnmnlial growth r r39 logistic grmx lh r39 l r A A 2 ll Time it gt 418 0 Reproductive TradeOffs O Semelparity reproduction only occurs once in an organism39s lifetime and then typically dies after reproducing Ex salmon agave I Occurs when survival rate of offspring is typically low and where the likelihood that the adult will survive to reproduce again is low 0 lteroparity Repeated reproduction Ex loggerhead turtle brazil nut I Favored in dependable environments where adult is expected to long enough to breed again and where competition for resources may be intense Biology Page 3 I Fewer but wellpositioned offspring 0 Rselection natural selection for traits that maximize reproductive success in environments that are not crowded Occurs in populations well below carrying capacity or where individuals face little competition Ex dandeHons 0 Kselection selection for traits that are sensitive to population density and are favored at high densities Densitydependent selection Kselection acts on pops near carrying capacity Ex humans if Selection m 0 Population Regulation Births and deaths Dispersal BDEpopulation growth OOO Selection i L 39lh up 7 paquot 4quot 3 9 J i a J I F iquot I 39 3 Tquot is i39 a if I fair In I39ll if Silurile ful llslimiting F iiifliuzepi ine Ii llquoti39t39 litt39 limmil El 151 til ii heftle mam rri Short life Super cial Il39 lilil innsh i 329 filmsill mature l Lilling lift Loin lltitlit39ltltii ilit 39 High jll39lll i39lfllllillit 39 Cfiaiiilllilll iililiEH quot mm 15 I Birth Immigration Deaths Emigration 0 Density dependent Limiting Factors determine carrying capacity of an environment for a species Population Size an be lumtwd by Natural disaster Competition Unusual weather Predation Parasmsm and disease 0 Factors that lessen population growth when density increases Places to live Pathogens transmission rate increases w high pop Predators easier to detect and capture prey Parasites easier to find host Biology Page 4 I E H llgll i 11wle film i Riellll relatllitiii lilips Density independent El Densitydependent regulation is a negative feedback loop higher the density the more some other factor reduces pop density 0 Densityindependent factors regulate populations I Ex prairie dogs were hunted by ranchers so the ferret population declined and is endangered because that was their main food source Prairie dogs are a keystone species therefore altering the density of many other dependent species I Predators can also limit the distribution of their pray Mussels are only found on exposed coastlines because their predators only live on sheltered coastlines O Bacteria are useful for studying population curves I Lag phase when you first inoculate plate I Log growth rapid increase I Stationary phase resources become scarce I Log Death phase population has used all resources and is rapidly declining Logor exponen al a gnounh 395 phase 8 a n 6 2 g Lag 2 phase 398 U o l 0 Time hr 0 Factors that allow populations to increase I Reduced infant mortality rate I Reduced overall mortality rates I Greater longevity I Females bearing progeny at a younger age 0 Clicker Question Why is the birth rate expected to decrease but world population growth is expected to increase 0 There is a lot of inertia built into population growth You can39t just reverse the expected growth rate quickly It is a very slow process 0 Clicker Question After being relatively stable for thousands of years why did human pop begin to dramatically increase beginning in 18005 0 Increased ease of transportation 0 Decrease in infant mortality rates 0 Clicker Question What exactly has allowed the human population to increase so dramatically and steadily since the 180039s Biology Page 5 0 Ancient sunshine fueled photosynthesis which led to current deposits of fossil fuels Biology Page 6 11302015 Ecosystem Ecology Friday November 20 2015 1223 PM Learning objectives Describe energy flow and nutrient cycling through an ecosystem relative to organisms living there Describe productivity via trophic levels 0 Laws of thermodynamics o 1 Energy cannot be created or destroyed only transferred 0 2 In ever conversion of energy some energy is lost as heat which increases entropy o 3 Matter cannot be created or destroyed only transformed Primary Production conversion of sun39s energy into chemical energy 0 Gross Primary Production amount of chemical energy as biomass that plants can create in a certain amount of time 0 Net Primary Productivity amount of carbon uptake after subtracting Plant Respiration RES from Gross Primary Productivity GPP o NPP GPP RES 0 Limitations to productivity in aquatic ecosystems 0 Light availability 0 Limitations to productivity in terrestrial ecosystems o Sunlight hours per day length of growing season 0 Water availability quantity and consistency o Nutrients Nitrogen and Phosphorous 0 Energy Transfer 0 10 of energy is transferred up to the next trophic level Tertiary consumers Secondary consumers Primary consumers Primary producers Biogeochemical Cycles Biology Page 1 Reservoir A Reservoir 8 Organic materials Organic avallable as materials nutrients unavallable as nutrients m Fossilization Living organisms detritus Respiration decomposition excretion Burning of fossil fuels Assimilation photosynthesis Reservoir D Reservoir C Inorganic materials Inorganic materials unavailable avallable as as nutrients nutrients Weathering Atmosphere erosion Minerals in rocks Formation of sedimentary rock mquot quot quot quot Figure 5513 0 Water Cycle Water Cycle 0 a Movement over land by wind e 4 Precipitation Evaporation over land from ocean 0 Carbon Cycle Biology Page 2 0 Nitrogen Cycle 0 Phosphorus cycle Carbon co2 in 1 atmosphere f A t39Photo Cellular sy esis rs pirati r 1 2 CVC I e A Photosyntheis Decomposition Den ation in i 1111 5 39 139 rpm An quotP39u r omposltloqj and sedimentation Biology Page 3 Nitrogen Cycle Phosphorus nn n r n Biology Page 4 1118 and 202015 Community Ecology Monday November 16 2 15 1221 PM IN THE NEWS Human domination of the biosphere rapid discharge of the earthspace battery foretells human future 0 Distinguishing features of Earth compared to other celestial bodies atmosphere water warmth and life 0 This may be the only body with intelligent life in this universe 0 The Earth39s core produces a magnetosphere that deflects solar radiation that would otherwise strip our atmosphere 0 70 of solar radiation is absorbed by the atmosphere or land 0 A small portion of solar radiation is absorbed by organic materials through photosynthesis that then become fossil fuels 0 Fossil fuels 0 Aerobic conditions organic material is recycled in the presence of oxygen gt no fossil fuels 0 Anaerobic conditions energy contained in biological material is not broken down by bacteria and can become fossil fuels Occurs in deep lakes or swamps 0 Laws of Thermodynamics o 1 energy is conserved but can be converted o 2 energies can flow and equilibrate o 3 there is a unique driving force for energy 0 We can convert between matter and energy but there is a balance 0 If we could collect the total amount of sunlight striking the earth for 6 hours we could fuel the Earth39s energy needs for a year 0 It is estimated humanity has lt1000 years left of available phytomass energy 0 Alternative energy sources 0 Testing being done on converting the oils of recent biomass into diesel through use of algae 0 Wood pellets can be used in place of coal although they contain much less energy 0 The ONLY solutions 0 Rapid increase in renewable energy sources 0 Rapid decrease in energy consumption Learning Objectives Understand how organisms interact with one another help harm or no effect using community ecologist terminology Describe the components that make up diversity Describe food chains and food webs Relate diversity to food webs 0 Today 97 of animal biomass is comprised of humans and their domestic animals 0 What does this mean for wild animals 0 Community Ecology study of an assemblage of populations of 2 species occupying the same geographic area at the same point in time 0 Interspecific interactions 0 Competition 0 Predation o Herbivory o Symbiosis Biology Page 1 I Parasitism I Mutualism I Commensalism o Facilitation 0 Niche how does the organism survive o Represents use of biotic and abiotic resources in its environment 0 2 species cannot coexist in the same niche for a long community of time o Niche partitioning one niche diverged from another to make both be able to survive I Ex 2 species of pocket gophers have overlapping ranges but do not have the same niche They burrow at different soil depths and textures so they can both coexist I Ex 2 species of lizards one species perches in sunny areas one perches on shady branches 0 Competitive interactions 0 Both species have less access to the resource due to the presence of the other 0 One species typically has advantage that allows it to outcompete other species gt competitive exclusion of one species 0 Character Displacement 0 Acid test for reinforcement is character displacement some character is more exaggeratedly different where multiple species coexist 0 Character displacement especially reproductive character displacement describes characters that are more divergent in populations that live sympatrically than in allopatric populations 0 Sympatric species show morphological differences to allow them to both compete for the same resources 0 Ex Where 2 species of flowers overlap one of them shifts from purple to red petals to allow pollinators to distinguish between the species and pollinate the correct flower 0 Predator Prey Interactions o If a predator is totally dependent on a prey the distribution of the predator is dependent on the distribution of the prey 0 Ex Canadian lynx and snowshoe hare when the population of the hare declines the population of the lynx species is closely and adversely affected 0 Ex Osprey feeds on freshwater fish Fish are avoiding shallow water to avoid predation The distribution of the prey affects the predator T Predator Population size C Time 0 Most systems in a food web are for more complex than just a single predatorprey relationship I Cryptic coloration camouflage I Aposematic coloration bright colors suggest they are poisonouspredatory I Mullerian mimicry 2 unpalatable species mimic each other to reinforce protection from predators III Mutualistic relationship III Ex 2 species of butterflies that are both toxic have the same markings Typically the more Biology Page 2 abundant species is the model and the less abundant species mimics them but this can be reversed I Batesian mimicry There is a toxic species that is the model and the palatable species is the mimic D Ex Monarch butterflies feed on milkweeds and acquire a bitter taste Yummy viceroy butterflies mimic the markings of the monarchs to protect themselves b Aposematic coloration b Poison dart frog a Cryptic coloration D Canyon tree frog c Batesian mimicry A harmless species mimics a harmful one d Milllerian mimicry Two unpalatable species mimic each other 4 Hawkmoth lt Cuckoo bee V Yellow jacket U 2039 Fearsco Eon31 cuquot in 0 Symbiosis when 2 or more species are in close contact with each other whether harmful or beneficial o Parasitism I Ex Pathogenic diseases like chestnut blight and pine blister rust o Mutualism I Ex Acacia and acacia ant have evolved to depend on each other coevolution D Plant has hollow thorns ants can live in D Plant produces small fruiting bodies for ants D Plant has Beltian bodies high in carbs and lipids D The ants protect the plant from herbivores and fungi I Ex yuccayucca moth pollination D Obligate mutualism B Female moths deliberately and effectively pollinate yucca D Moth also deposits some of her larva in the pollen I Lichen is a mutualism between a fungus and alga or cyanobacteria I Reef cleaning stations 0 Commensalism 0 0 Facilitation or 0 I Species can help other species survive without living in close contact with them D Provides refuge from stress predation or competition Improved resource availability and transport 9 Ex gut flora lichen corals mycorrhizae 0 Refuge from physical stress If your seeds land under the canopy of a nurse plant the nurse plant can provide shade water and nutrients to the seeds 9 Refuge from predation Nurse plants may also prevent herbivory of seedlings growing under Biology Page 3 them 9 Refuge from competition Seeds growing in nurse logs don t have to compete with plants and mosses that grow on forest floor 9 Transport pollinators may increase reproductive success by reducing pollen waste and increasing dispersal Pollinators gets a reward nectar fruit or pollen 0 Succession sequential change in a community over time often following a disturbance 0 Primary Succession colonization of organisms in a newly created habitat with no recent occupation I Ex retreating glacier 1 Pioneer fireweed 2 Dryas stage 3 Alder stage 4 Spruce stage 0 Pioneer stage with o 5 1o 15 fireweed dominant 1350 Kilometers t Alaska Q s 1 I 0 Spruce stage 0 Alder stage 0 Secondary Succession occurs when a place occupied by organisms experiences moderate disturbance Plcmeequot memes Latesuccessional species Tolerance for high sunliglht Large mot system Resistance to wind i Better water conservation Tolerance for nutrient poor SOIlS lDeepn roots Taller to outcompete ot hiers for Salinity tolerance Sumlght Windldl39i spersed seeds W ate rxdl39i spe reed seedls rselected species Ksellected species 0 Trophic Interactions 0 There is detritus at every trophic level p v f r I h The quotxquot cm 4w Biology Page 4 f The quotXquot en geese 5 39 4 fox interaction ihdipates that this interactien is E partly suppressed V 39 when shew geese quotT nest in asseciatiph j V l u Q with snowy owls in if Mr peak lemming I 39 y 1 V M V o 39 l 0 kl 1 3 l lfl 9 3 9 I d Q a l 0 V 0 Clicker Question What happened when wolves were reintroduced to Yellowstone National Park in 1995 0 Every aspect of the ecosystem benefitted Biology Page 5 11302015 History of Life on Earth Monday November 33D 2 15 124 PM Learning Objectives Know the age of the universe solar system and Earth When did life first arise on Earth How have the Earth s atmosphere and oceans changed over geologic time How have living organisms transformed the land oceans and atmosphere of Earth When did the different major groups of organisms evolve Understand that nothing on Earth is static but rather life is sustained by a complex balance of biotic and abiotic systems Clicker Question How old is the Earth 0 46 billion years old Universe arose 3914 billion years ago through Big Bang 0 Our solar system arose 46 billion years ago 0 First evidence of life is 35 billion years ago 0 Our galaxy formed 3910 billion years ago Earth39s crust formed 44 billion years ago and is 40 km thick 0 Affects climate sea level and biological evolution Earth39s atmosphere was primarily H and He 0 Due to volcanic gases those were retained in our new early atmosphere after H and He were stripped by solar winds 0 Today the atmosphere is Nitrogen 77 02 21 H201 Argon C02 Traces of methane and particulates 0 Most C02 is locked up in crystal rocks or dissolved in oceans Earth39s Oceans 0 Water was on land 43 billion years ago 0 Geochemical cycles as we know them were established about 1 billion years ago 0 Fossil Record 0 Fossils are found in sedimentary rock 0 Dating methods I Relative position sediment deposits in relation to other deposits El Original Horizontality rock is laid down horizontally due to gravity If the rock layers are not horizontal then some kind of deposition or tectonic activity has occurred since the formation of the rock layer El Superposition Older rocks are below younger ones I Index species If a species is found in the sample that we already know the age of it helps us determine the age of the unknown fossil III Diagnostic fossils El Principal of biotic succession illustrates sequential strata I Radioisotopes El Halflife The time it takes for half of the isotope to decay Used to calculate age based on concentration of isotope 0 Problem sometimes the decayed daughter material is lost to the environment and Biology Page 1 skews aging I Carbon dating El Ratio of C14 to C12 El C14 is in upper atmosphere and all living things I C14 decays into C12 when something dies El Halflife 5700 years I Works best for organisms that are preserved but not fossilized and lt50000 years old I Other methods I Geomagnetic reversals The N and S poles of the Earth flip over the course of LOGO10000 years We don39t know when the next one will happen You can look at iron deposits and age rock based on where polar north was 0 Life Assemblage organisms are collecting and fossilizing in the habitat where they lived 0 Death assemblage become fossilized somewhere other than where they lived PreCambrian Life Archaea Eubacteria and Eukarya Multicellular eukaryotes are lt1 billion years old First definite evidence of life is 35 billion years ago Clicker Question Which organism had the greatest impact on Earth39s oceans and atmosphere I Cyanobacteria 0 000 O Cyanobacteria I Stromatolite colonies of bluegreen algae that from biosedimentary dome of calcium carbonate Some of the earliest fossils Primitive atmosphere did not have oxygen From photosynthesis of cyanobacteria oxygen was able to start building up in the atmosphere and resulted in many organisms adapting to do aerobic respiration I The first oxygen was absorbed by the rocks and was poisonous at first but as more photosynthesis occurred oxygen built up and became useful to life I Atmosphere started to rise 22 billion years ago 0 0 Rise of Eukaryotes O Endosymbiont Hypothesis chloroplasts ingested but did not destroy cyanobacterium 0 Hydrogen hypothesis freeliving alpha proteobacterium formed a symbiosis with an archaeon partner This union of two prokaryotes gave rise to the host cell archaeon and the mitochondrion Ediacaran Fauna early metazoa 0 Evolution of multicellular organisms I Hox genes dictate the duties of particular cells for particular purposes I Found in all animals from Cnidaria up excluding sponges O Crawled on anchored to sea floor Flat and segmented soft bodies 0 640 million years old 0 Atmosphere was welloxygenated at this point Photosynthesized Cambrian Radiation 0 Sta rt of Paleozoic Era 0 Many taxa we have today originated here 0 Cause of this radiation We don t know Biology Page 2 I One hypothesis development of mesoderm permitted organisms to go from being flat to tubular O Organisms now had hard skeletal tissue why 1 Receptacles for excess minerals 2 Storehouses for scarce minerals Ex calcium phosphate 3 Support and muscle attachment for locomotion 4 Protection 5 Internal environmental control We think predation was the leading cause for development of exoskeleton Cambrian fauna 0 Huge predator Anomalocaris canadensis dominated the sea 0 Flora mostly single celled algae Trilobites were common Ancestors of modern insects and crustaceans Nautiloids were long straightshelled mollusks OO O Ohordts l a i Brachiopods O r Jawless vertebrates O Paleozoic Era 0 Warm time with highest sea levels in history 0 Southern continents were a single land mass Gondwana Panthalassic Ocean C880 A quot ro otethys K Arc apetusO J t u V 7 acgmc v quotii Ordovician Period 0 Ordovician rocks are mostly sedimentary O Brachipods bryozoans molluscs Biology Page 3 Fourfold increase of fauna Top predators nautiloids and starfish Agnathan vertebrates On land Arbuscular mycorrhiza is one of the earliest fungi Formed symbiosis with early plants and made nutrients available to them I Oldest land plants liverworts Ordovician Period ended with second largest extinction of all time 0000 O Silurian Period 0 Jawed fishes arose I Agnathans lacked jaws and had paired fins I Gnathosome jawed and ventral fins Placozoans This is when life really colonized land Plants began to stand upright ferns clubs mosses horsetails Earliest arthropods spiders mites scorpions millipedes centipedes Amphibians that came on land OOOOO Carboniferous Period 0 Gondwana and small northern continents form Late Jurassic 152 Ma Anon Lunanu 39 Modem Wu 6 Socnarzn Echo Harvn mm ml39h Wanem d wanton Cosh31 budquot PM Extensive vascular forests Winged insects Amphibians diversify and reptiles appear Widespread tropical climates large swamp systems Horsetail club moss and ferns dominated This was the last time in Earth39s history that large coal deposits could form I Because termites and cellulosedigesting insects had not yet arisen 0 Seed plants diversified due to wind pollination OOOOOO Permian Period 0 First egg layers 0 Pangaea formed and sea level dropped to lowest point in Earth39s history and altered climates O Largest mass extinction in history I At least 52 of families of skeletonbearing marine invertebrates went extinct 96 of all species Biology Page 4 I Most marine life perished I Extinction caused by change in ocean chemistry El Siberian Traps form large region of volcanoes in Siberia and volcanic activity continued for a million years I Dust in the atmosphere lowered temperatures drasticallygt widespread glaciation El Gases put into atmosphere primarily COZ dissolved in ocean and led to ocean acidification killing organisms with calcium carbonate shells Mesozoic Era 0 0000000 Fragmentation of the land masses allowed speciation in many different habitats Temperatures reached an alltime high Marine organisms that survived diversified Gymnosperms seed plants without flowers dominated the flora Cycads and conifers Later Angiosperms flowering plants developed and displaced gymnosperms Many insects arose during this time pollinators made angiosperms dominate DINOSAU RS went extinct very suddenly after massive asteroid hit I Layer of iridium deposited very quickly I Shocked crystals at site of impact suggest massive force I Inhibited photosynthesis collapse of food chains no animal gt50 lbs survived Temps dropped 395 degrees F Cenozoic Era 0 00000 65 mya to present Separation of continents Bering land bridge and isthmus of Panama Glacial expansion and retreat Large mammals and birds went extinct due to human hunting Humans developed agricultural practices Summary 0 O 0 Earth forms 46 billion years ago Solid surface forms 4 billion years ago Life starts 38 billion years ago Age of Bacteria Archaean era Oxygen atmosphere develops 2 billion years ago Eukaryotes develop Proterozoic era Ediacaran life 650 million years ago First multicellular life forms unknown today Cambrian explosion most current life forms appear 550 million years ago Paleozoic era 550 250 million years ago Marine invertebrates fishes amphibians invasion of the land Coal formation Permian mass extinction 250 million years ago 95 of all life dies end of Paleozoic Mesozoic 25065 million years ago Age of the dinosaurs reptiles Mammals birds and flowering plants appear Biology Page 5 O Cretaceous mass extinction asteroid hits the Earth killing much of life including the dinosaurs O Cenozoic era 65 million years ago till present Mammals dominant Biology Page 6 1242015 Extinction Friday December 4 24315 444 PM Learning Objectives How is extinction defined What constitutes a quotMass Extinctionquot event What are the causes of past mass extinction events What roles have humans played in the extinction of plants and animals What is meant by quotOcean Acidificationquot What is meant by the term quotLazarus speciesquot 0 Parasite wiping out Swollen Raiatea Tree Snail Dr Dashach witnessed the extinction of it 0 Clicker Question Which of the following are not extinct o Javan Rino 0 Extinction is a new concept 0 Charles Darwin came up with this idea 0 Baron Georges Leopold Cuvier some sort of terrible event would have to wipe out an entire species 0 Signs of God39s design in nature God created a perfect world so animals would not become extinct Thomas Jefferson 0 What causes extinction 0 Habitat loss 0 Temp change 0 PoHu on 0 Over harvesting of plants and animals 0 Nonnative animals and plants 0 Extinction and evolution BOTH correlate with environmental change 0 Become versatile move or become extinct o If the population has the ability to migrate to a place where the environment still suits their physiology and lifestyle it can survive o quotIf there is enough natural genetic variation in a population to survive the extremes of environmental conditions it may survive although strictly speaking a species cannot become39 more versatile it can only be preadapted and selected for versatility If neither of these conditions are met a population will die out If there are no other members of this species living in places that are not undergoing rapid environmental changes then the species will go extinctquot 0 Dinosaurs went extinct bc they could not migrate and did not have adaptations to be versatile 0 KT Boundary when the sun was blocked out from the debris of the volcanic eruptions 0 animals had to be able to scavenge or hibernate to survive 0 Not as much plant extinction as animals at this time 0 Mass extinction extinction of a large number of species 75 within a relatively short period or geological time 15my 0 5 major mass extinctions 1 Late Ordovician Biology Page 1 439 mya 60 of marine invertebrate genera go extinct Marine fossils are common because calcium carbonate shells easily fossilized and could easily and quickly be covered with mud Late Devonian 367mya 57 of marine invertebrate genera go extinct Late Permian 245mya 82 of marine invertebrate genera go extinct Late Triassic 208 mya 53 of marine invertebrate genera go extinct Late Cretaceous 65 mya 47 of marine invertebrate genera go extinct unique because there was a known cause of extinction Gradual increase in number of genera on earth Minor extinction events between these mass extinctions Ordered from largest extinction to smallest P gt O gt D gt Tgt C Ordered from oldest to most recent 0 gt Dgt P gt T gt C O 000 Extinctions increasing rapidly o Mammals the most then birds then vertebrates then invertebrates quotAverage rate of vertebrate species loss over the last century is 100x faster than the background ratequot 0 quotAre we in the midst of a 6th mass extinction Cause of extinction is not exactly known but is always related to when the environment changes rapidly and the organisms do not have the ability to adapt to those changes 0 Increase in human population seems to be causing increased rates of extinction Quaternary extinction event 1200015000 years ago 0 Large amounts of genera of large mammals became extinct when humans inhabited new land areas and hunted 0 North America South American and Australia all had large amounts of extinction while Africa did not I Why We coadapted with the animals in Africa when we migrated elsewhere we were the introduced species Temperature increasing throughout the world somewhat correlates with large mammal extinctions however human migration graphs correlate perfectly with large mammal extinction Known causes of animal extinction 0 Hunting species introductions habitat destruction 0 Changing the chemistry of the oceans and atmosphere has been humans39 greatest impact Ocean acidification Henrys law average ocean pH is about 81 C02 in water reacts with water and becomes carbonic acid fewer available carbon ions for organisms to utilize 0 Based on projections of C02 increase the rate of pH decline is in free fall 0 Due to ocean acidification oysters have not been able to reproduce on their own since 2005 in Washington State Permian extinction 0 ocean pH plunged to 76 O 90 of marine life died and multicellular life on Earth nearly went extinct o This is going to happen again at this rate Biology Page 2 0 Siberian Traps series of super volcanoes that were the source of C02 that caused the Permian extinction 0 Lazarus species is a species that disappears for one or more periods only to appear again later 0 Southern white rhino 0 Many species thought to be extinct actuay aren t 0 Ex the Bermuda petre Biology Page 3
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