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ALL Dr. Quinn Class Notes

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Biology
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BIOLOGY 1M03
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James S Quinn

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Dr. Quinn’s Notes Feb 27 Causation of Behaviour  Proximate – the immediate sequence of physiological effects that lead to the behaviour o HOW?  Ultimate – the adaptive value or evolutionary origins of the observed behaviour o WHY?  Basis of Behaviour  Environment/Genetic o Learned Behaviour –--continuum--> Genetic Behaviour o Epigenetic Traits – markers of DNA (turns genes on and off) Evidence for a Genetic Component to Behaviour 1. Deprivation Experiments: o Prevents learning opportunities through isolation of subject o Squirrels Burying o Spiders Web Spinning o Kangaroo Rat o Fixed Action Patterns  Pattern that appears, essentially complete and is played out to completion once activated by a simple sensory cue  First performed without training  Stereotyped and predictable  Sensory cue o Sign stimulus – external stimulus that triggers FAP o Releaser – stimulus that signals from one individual to another 2. Selection Experiments a) Hold environment constant b) Measure phenotype c) Breed Individuals with extreme phenotypes together d) Measure phenotype in next generation e) Back to C R.C. Tryton’s artificial selection experiment Through selective breeding of the bright with the bright and the dull with the dull generation after generation, Tryton produced populations of rats that either made maze errors (entering blind alleys) or made few such errors o A change in mean behavioural phenotype in Tryton’s selection experiment means that o The change is genetically based o The proficiency to learn a maze in partly genetic 3. Crossing of Genetic Strains o “Hygienic bees uncap and remove dead larvae” 4. Molecular Genetics o Eg/ Mono-Amine Oxidase (MAO) Mutation o Breaks down neurotransmitters as they are not broken down normally o Hyper-aggressive disorder o Homologous genes have been subsequently discovered honey bees and the roundworm Caenorhabditis elegans Feb 29 Development of Behaviour  Instinct: A Behaviour pattern that reliably develops in individuals that receive adequate nutrition and that is given in functional form on its first performance  Learning – a durable and usually adaptive change in an animals* - to experience by that -  Pink Cockatoo o Large birds, common in Australia o Overlap in range with the Galah o Build nests – raise young o Two species come together, both using the same next hole – pink cockatoo always wins because it is bigger o Cockatoo will lay the eggs – sometimes end up with a galah egg with pink cockatoo eggs raised by the cockatoo  Call Types o Begging Calls – begging for food from parents o Alarm Calls – given in presence of predator o Contact Calls – maintain associations with parents/flock  Results of Natural Experiment o Galah chick raised by pink cockatoo o Galah begging call – innate, genetically based (nature) o Galah Alarm Call – innate (nature); pink cockatoo may not even know what the alarm call means o Contact Call – learned Types of Learning  Habituation – repeated stimulae without appropriate feedback or unimportant stimulate (idle threats) o Habituates only to the unimportant stimuli  Imprinting – structured learning; critical periods, Life-long learning, often involves mating  Associative Learning – association of stimulate o Classical Conditioning  Eg/ Pavlov’s Dogs –food, salivation experiment, light/bell o Operant Conditioning – trial and error  Eg/ Trial and error – toad bites brightly colored millipede and is disgusted – will never eat it again (taste aversion)  Insight Learning – correct behaviour on first try (by reasoning, not instinct) o Eg/ Raven, meat string pull - figured out how to get meat just by looking o Eg/ Caledonian Crow, creates tools out of twig and leaves o Eg/ Crow – glass tube with food at bottom, tube too long for beak to reach, given a piece of wire – crow is able to make a tool out of the wire by making a hook and being able to pull food out  Play – physiological/social/cognitive practice – developing skills o Eg/ Baboons – leaping, fighting – practicing it in “play”  Fixed Action Patterns o Eg/ Chick would peck at red spot and male would regurgitate fish for chick  Instinctive to peck at red  To Recap: Instinctive behaviour changes over time in some cases, and the changes involve learning The degree to which evolution has shaped learning ability through genetically based neural substates  Predisposition for associative learning has been shaped by evolution (genetic constraints)  Rat o Sweet water, the follows with radioactivity that makes rat rick – learns not to drink sweet water – associates taste with nausea o Rat gets a shock when bell rings – associated sound with pain o Difficult to train rat to not drink sweet water by giving it a shock – hard to learn taste and pain o Hard to learn sound with nausea o Nature of cue and consequence determines whether rat can learn quickly to modify behaviour o Taste  Nausea Small samples of new food – omnivorous diet o Sound  Pain Warning of predators or other rats o Taste Aversion – taste associations are easily learned in species that might encounter toxic foods o Natural selection shapes your brain to associate certain things  Most mammals tested learn taste aversion easily  John Reynolds, Jeff Galef and colleagues asked if this was related to the risk of encountering toxins in their diets o Eg/ Vampire bats do not experience “bad blood” – looked at 3 different kinds of bats  Fruit Eating – learn taste aversion easily  Big Brown Bats – catches insects, learn taste aversion easily  Vampire Bat – sneak up on undulates, use teeth and cut skin near the ankle and lap of blood – only feed off live animals, blood is not toxic – does not learn taste aversion easily  Hypothesis – a neural substrate for rapid learning of taste aversion is not maintained by stabilizing selection in vampire bats  Prediction – vampire bats cannot easily learn taste aversion  Methods 1. Each species was fed foods with a novel flavour (cinnamon or citric acid) followed by a. (Experimental) an injection that made them sick OR b. (Control) an injection of saline that had no affect 2. Later – after recovery of sickened bats, they were tested to see how much of the novel flavoring food they would eat Mean (+/- SE) amount of flavored diet ingested (expressed as a percentage of the total amount ingested) by subjects in experiment 2 assigned to saline (S) and unpaired taste-toxicosis (UC) control groups and intermediate (I) and delayed (D) experimental groups. The left panel describes food choices of common vampire bats and the remaining three panels show food choices of frugivorous and insectivorous bats  A neural substrate for rapid learning of taste aversion is not maintained by stabilizing selection in vampire bats  Rapid learning of taste aversion occurs in other bats and mammals that may experience toxic foods  Evolution shapes learning!  Nobel Prize Winners o **1973; Niko Tinbergen, Konrad Lorenz and Karl von Frish o Studied behaviour from a proximate perspective  Stotting Springbak (Antelope) o Runs around when sees lion o Used to think that it was altruistic behaviour and that the antelope was sacrificing itself to warn the pack o In reality – antelope is proving to the lion that it is strong and fast and the lion leaves  Wynne Edwards o Animals assess population sizes and will forgo breeding if there are too many of them o Epideictic display – flock of birds flying; thought they were assessing numbers o View of life  Too many birds, not enough food – don’t breed  Selfish breeders  Altruistic breeders – don’t want to exhaust environment  Breeding season – selfish breeders will breed; more S’s in population  Will occur until they use up all resources March 1 Hamilton’s Rule  Some behaviours are costly to self and benefit others  Darwin struggled to explain sterile worker bees and ants  “Would I lay down my life to save a brother? No, but I would save two brothers or eight cousins” – Professor J.B.S. Haldane (1892-1964)  Hamilton’s Rule – an individual should help another when following inequality is met o rB > C o Where  r = coefficient of relatedness  B = Darwinian fitness Benefit to the recipient  C = Darwinian fitness Cost to the donor o Male Haploid, one copy o Queen female, diploid two copies o If fed normally – worker bees o Fed royally – queen bees o What is the likelihood that a rare allele came from mom? 50% o What is the r value between two sisters?  0.75  Hymenoptera females are less related to their own Daughters (r-0.5) than they are to their sisters (0.75) o Worker female bees are shown tending to their larval sisters  Kin selection also works in diploid systems o Termite queen is tended by workers o Naked Mole Rats  The Queen (pregnant below) lives in the central chamber with one or more “Kings” tended by non-ovulating workers  Workers are related to breeders and many colonies are quite highly inbred and share many alleles in common  Direct Fitness + Indirect Fitness = Inclusive Fitness o Indirect = through non-descendent young o Some critics claim that evolution does not explain human kindness o This implies an ignorance about the subject  IClicker o Blue collar crime = selfish behaviour which can be favored by natural selection because it can increase the amount of money or what the crime is worth o Natural selection doesn’t explain providing help for an unrelated friend  Can be explained by reciprocal altruism How Can Evolution Explain Helping Others?  Kin Selection (Inclusive Fitness)  What about Non-Kin? (Friends)  Reciprocal Altruism o If the fitness benefit to the recipient > the fitness cost to the donor, both participants will gain if the help is reciprocated at a later date o Cooperation with a time delay  BenefiR > CostD  Long term association (opportunity for reciprocation)  Individual recognition  Detection and punishment of Cheaters o Vampire Bats  Feed on blood  Cannot survive > 3 days without feeding 1. Associate with kin and non-kin roost mates 2. Regurgitate to kin 3. Regurgitate to kin and non-kin who regurgitate to them  BenefiR > CostD  Long term association (opportunity for reciprocation)  Individual recognition  Detection and punishment of Cheaters March 5  Example of Reciprocal Altruism o Smooth-billed anis in Puerto Rico 2011  “Referential alarm calling”  One call for terrestrial predators  Separate call for aerial predators o Peregrine Falcon o Red-tailed Hawk o Terrestrial-threat Alarm Call o “Chlurp” (Aerial-threat Alarm Call) o White Noise Control (matched to specific chlurp played to group) o North East NS o Rickety Gate Terrestrial Alarm o South Farm Mid-Fence Chlurp Why Warn Others  Reciprocal altruism or other form of reciprocity?  Benefit for some individuals to be in large groups?  Ongoing work… more to come  Natural selection for larger brain size: 1. Complex foraging o Skillful hunting may benefit from enlarged brains o Food sharing leads to increased sociality and other forms of reciprocity o Specialization and risk reduction leads to pair bonding and shared parenting (rare in mammals)  monogamy or polygyny 2. Cooperative breeding and complex social interactions (associated social competition) o Recall that Homo sapiens has long development time and short inter-birth spacing o Recent studies argued that H sapiens is a cooperative breeder o Cooperative breeding in humans explain how we can have long development time and reduced inter-birth intervals o Enhanced social skills may benefit from big brains  Understanding care givers may allow smart kids to gain more care  Smart negotiators may gain fitness within social groups 3. Cooking with fire o One human activity that is not shared by any other species: cooking food (controlling fire) o Carmody and Wrangham (2009)  Provide evidence that cooking decreases the digestion costs of human foods, allowing a reduction in the size and cost of the digestive system  They argue that this may explain the last increase in brain size in Homo sapiens  Conclude that cooking benefits exceed other non-cooking food processing: gelatinization of starch, denaturation or proteins and killing of foodborne pathogens being the most significant gains  These energetic improvements over eating raw foods may have led to decreased investment in the digestive system and increased energetic investment in our “growing” brain”  Constraints on brain size increase: 1. Temperature sensitivity of the brain 2. High metabolic cost of the brain (20% of resting metabolic cost, 2.5% of body weight) o 1 brain size increase corresponds increased meat consumption – high quality food o Emergence of Homo erectus and H. ergaster from Australopithecine ancestors o Small stomach and large brain (subsequently challenged)  Recent Study by Navarette et al. 2011 o Study of mammals in general suggests that increased brain size correlated with reduced fat levels and less so with reduced digestive system o Homo may have had a reduction in both fat and digestive system  Efficient bipedal locomotion  Steady and high quality food supply (partly due to cooking)  Less need for fat The expensive-brain framework proses complementary pathways for an adaptive increase in relative brain size 1) Brains can get larger when energy inputs are stabilized on a higher level (higher total metabolic turnover) through - An increase in mean dietary quality (eg/ more animal fat and protein in early Homo) - Energy subsidies from other individuals (eg/ cooperative breeding, allomaternal care) - Reducing fluctuation sin energy inputs (eg/ cognitive solutions including culture 2) At constant total energy intake, energy allocation to other functions may be reduced, such as locomotion (eg/ efficient bipedalism) or production (eg/ slower life history pace)  We propose that during human evolution improved diet quality, allomaternal subsidies, cognitive buffering, reduced locomotion costs and reduced allocation to production all operated simultaneously, thus enabling the extraordinary brain enlargement in our lineage Genetic Features of People  Comparisons with our nearest living relative: o Human and Chimp Genome projects o 1.06% fixed difference in DNA sequence (ignoring repetitive DNA and indels) o 13,454 homologous proteins shared o 29% of these proteins have identical AA sequences o Many of the other proteins have small changes that may not affect the proteins function  Many DNA changes may be neutral and under genetic drift  Some changes may be favoured by natural selection  Genetic drift acts on synonymous or non-synonymous substitutions  Selection acts only on non-synonymous substitutions  Directional selection favours base changes that have a positive effect on protein function March 7  Genetic code is redundant – doesn’t matter whether they change; natural selection will not play any role in dictating whether these mutations move forward in the population  Some mutations will affect amino acid  Genes with a high ratio of non-synonymous to synonymous changes indicates directional selection  However, in some cases, on or few mutations will change the protein appropriately to the gene will not stand out in N-S/S ratio o Eg/ FOXP2 gene – 2 substitutions led to large changes in speech ability in humans  Mutation in FOXP2 gene gives rise to language impairment (Specific Language Impairment, SLI)  Only a small fraction of protein coding genes show evidence of positive selection since the divergence of humans from chimp lineages  What about non-coding DNA sequences? o Why might non-coding DNA matter?  DNA regulation!  In 202 of the 35000 regions, human sequence had a significantly faster rate of change compared to other taxa (they included an additional 9 vertebrate species) o These 202 Highly Accelerated Regions were ranked and named – HAR 1 was the fastest of the fast. HAR 202 was slowest of the fast o HAR 1 (118 bp region on human chromosome 20) showed only 2 bp changes between chicken and chimp  There were 18 changes between chimp and humans, an 80x increase in the rate of evolution  HAR 1 codes for an RNA molecule that folds into a stable structure  Such as RNA molecules  specific protein  regulate gene expression  HAR 1 is expressed only in the brain, especially during development  HAR 1 associated with “reelin” protein, which plays a role in developing layered structuring characteristic of human brains but not of other species brains  Rapid changes in human HAR 1 are likely related to the fast evolution of the larger and more complex human brain  The study of such gene regulatory regions is in its infancy and will likely prove crucial to our understanding of the evolution of differences among species including our own Genetic Variation and Natural Selection in Homo Sapiens Human Skin Color  Skin color is partly genetic – “the 8818G allele of the agouti signaling protein (ASIP) gene is ancestral and is associated with darker skin color in African Americans” o Genetic Evidence for the Convergent Evolution of Light Skin in Europeans and East Asians  Skin color is linked to the environmental conditions of the place that these people evolved – due to natural selection  Melanin protects against UV radiation with its ability to prevent direct (blocking) and indirect (scavenging reactive oxidative species) damage to DNA at wavelengths where it is most vulnerable  Constitutively dark skinned folks have a sun protection factor (SPF) of 10-15 while moderately pigmented people like those form the Mediterranean achieves an SPF of only 2.5  Lighter constitutive pigmentation is associated with a higher sunburn response, a lower tanning response and a greater susceptibility to skin cancers  Vitamin D3 o Necessary for efficient use of dietary calcium o Needed for proper growth of bones in vertebrates o Shortage of Vitamin D 3eads to weakened bones (Ricketts disease) and recent evidence suggests a link with immune dysfunction and cancers o Synthesis/Breakdown – facilitated by UVB  Vitamin D3is made from 7-dehydrocholesterol  7-dehydrocholesterol found in keratinocytes of the epidermis, absorbs photons from UVB  Vitamin D3production is facilitated by UVB exposure  Vitamin D3and pre Vitamin D 3tages are broken down by UVB radiation (preventing Vitamin D “intoxication” from excess vitamin)  Melanin absorbs and scatters the UVB wavelengths that catalyze Vitamin D3synthesis o The photo conversion of 7-dehydrocholesterol to pre-vitamin3D in the skin is also adversely affected by:  Increasing age  Clothing  The Use of Topical Sunscreens (blocked UVB that is responsible for both sunburn and vitamin D3production) o Factors favoring dark skin in tropics:  Human skin is almost hairless- cooling through sweating is more effective  Melanin protects skin from UVA and UVB damage  UVA breaks down folic acid (folate)  Adequate folate status necessary for proper DNA synthesis, repair and expression  Folate deficiencies play a negative role in reproductive and developmental processes (neural tube defects, early pregnancy losses among others)  Predictors of Skin Color o Average UV MED (average UV radiation induced minimum erythral dose) – minimum dose of UVR to cause slight reddening of lightly pigmented skin o Average UVMED correlates with latitude and varies also according to precipitation levels and seasonal UVMED o All these factors were combined to predict optimal skin color as a function of UVR exposure o Actual measure of skin color of aboriginal populations match predictions well March 8 Lactase Persistence – Genetic Basis  Single Locus with two alleles  LTC*P/LTC*P  synthesize lactase and digest lactose as adults  LTCP*P/LTC*R  synthesize lactase and digest lactose as adults  LTC*R/LTC*R  do not synthesize lactase and unable to digest lactose as adult a) The frequency of lactase persistence is higher in north-central Europe (red) and declines toward the south and east b) The amount of genetic diversity for milk proteins in domesticated cattle is highest in north-central Europe (red) and declines toward the south and east. The dashed lines give the limits of the earliest Neolithic cattle pastoralists (called the Funnel Beaker culture) as inferred from archaeological data  Inuit because of their diet can afford to have dark skin  Skin color doesn’t match expectations because of environment  Beja pastoralists – live in deserts, nomadic, hardly no water, survive on milk  Humans are the only ones who drink milk when they are adults  These people are lactose tolerant  High diversity of milk protein = where cattle developed  Cant say that these people HAD to drink milk – could make cheese + yoghurt which doesn’t have a lot of lactose Milk “keeps” in Northern Europe  Stored for production of cheese or yoghurt (low in lactose)  Vitamin D facilitates gut uptake of calcium  Light levels low in winter  low levels vitamin D  rickets and osteomalicea (bone disease)  Calcium from milk may impair Vitamin D breakdown in liver  Milk proteins and lactose apparently facilitates adsorption of Calcium and milk contains high calcium levels  Northern Europeans with Lactase persistence are less prone to Calcium shortage and bone disease Detecting Selective Sweeps  Beneficial mutation favored by natural selection  Imagine this situation if there were no crossing over and recombination – then the whole chromosome would spread through the population and a genetic marker of this chromosome would detect presence of the mutation  But *** crossing over happens  When a new favorable mutation initially spreads, it will be surrounded by a large chunk of the same sequence. This sequence is linked with the mutation and is called a haplotype  Mutation, crossing over event, mutation is still associated with chunk of DNA  The haplotype will remain intact until recombination breaks the linkage – this takes around 10000 years depending on the size of the haplotype Lactose Persistence  Directional selection in populations with history of dairying  “Selective sweep” allows molecular evidence of this o Strong selection; mutation in region of DNA that affects lactase persistence – strong selection if it is beneficial, will also favour genes around this mutation  will be carried as a “block” throughout generation o 4 different haploid types – each block is identical o Selection will favour entire block of DNA – block of DNA will appear in striking numbers, increasing dramatically – should be able to go into population, find area of mutation and show blocks of haplotypes in individuals; very rapid selection o During selection, recombination can occur Frequency of “Lactose Malabsorption” in 39 countries Distribution of primary adult LM along 91 populations plus 9 nomadic low-latitude, lactose- absorbing populations Graphs – patterns based on geography or cattle for lactose absorption/malabsorption  Farther from equator – the better you can digest milk (lower lactose malabsorption) o Siberia and Greenland are exceptions o Far north – hard to keep cattle – not had selection for being able to digest lactose  High levels of malabsorption in hot areas, low levels of malabsorption in cool areas o Except Siberia and Greenland  Cattle diseases- low cattle disease number, more people can absorb lactose o High levels of malabsorption If more cattle disease  Lactose Malabsorption is found in high frequencies predominantly in low latitude, high temperatures and areas with a high number of cattle diseases  Barriers to dairying seem to explain pattern of lactose malabsorption  Lactose digestion ability in mature people of dairying ancestry may exemplify culture as a selective force driving organism evolution  CULTURE DRIVING EVOLUTION  Skin color is not a good variation to compare genetic similarity  goes east to west, not out north/south  Race is only skin deep! March 12 Evolutionary Psychology  Application of evolutionary concepts to understand human behaviour  Human cognitive abilities have been shaped in specific ways by natural selection over 30000 to 40000 years of evolution  Most of our evolutionary history was probably spent as small bands of cooperative hunters and gatherers  Food sharing was probably essential, organized as a form of reciprocal altruism  Food sharing likely favored adaptations facilitating attention to fairness in social exchange and attention to breaking of social contracts Environment of Evolutionary Adaptedness (EEA)  We evolved for a large part of our history under a certain set of environmental conditions that don’t match the environmental conditions today  Some of our traits do not make sense for the environment we live in today  Human behaviour was shaped during our long evolution as hunter gatherers  Complex behaviours  shaped over long time frame  Modern human environment is strikingly different from that which we emerged  Genetic constraints limit or shape learning o Our brains may be designed to solve the kinds of problems that our ancestors faced when they lived in small foraging bands o Small cooperative bands  Subsistence by hunting and gathering  Controlled fire  Had home bases  Talked, shared cultural beliefs, ideas and traditions o Exploited resources and then moved on?! o If our ancestors lived like this for many tens of thousands of years they should have brains that are shaped to solve problems faced in that social setting… such as detecting freeloaders in social exchanges o We communicate with our voices, ape relatives can learn sign language and can communicate that way o Slide 8 – blue dominant trait; 50:50; dominant mutation in fox P2 gene o SLI causes difficulty learning to speak – small vocabulary and poor grammar as adults o Pattern *  As seen earlier, organic evolution and genetic traits influence behaviour and in this case – language and culture o Culture also influences organic evolution  Evolutionary changes in genes such as FOXP2* Shared Human Characteristics  Inbreeding avoidance  Chimps and gorillas can taught to communicate non-verbally  As seen earlier, organic evolution and genetic traits influence behaviour and in this case – language and culture  Evolutionary changes in genes such as FOXP2 and others facilitated language, which affected our culture greatly  If ancestors lived like this for many tens of thousands of years they should have brains that are shaped to solve problems faced in that social setting… such as detecting freeloaders in social exchange Natal dispersal I non-human animals  Birds  typically females disperse farther than males or both sexes “shotgun disperse” after fledging  Mammals  typically males disperse once reaching maturity (eg/ deer mice) Incest Avoidance  Breeding with kin increases homozygosity  Loss of homozygosity (reduced heterozygote advantage)  Increased risk of homozygous deleterious recessives (eg/ human recessive diseases  PKU, Tay-Sachs disease, cystic fibrosis)  Inbreeding o Why is it bad?  Dominance  Heterozygote advantage  The more related to your mate the greater reduction in fitness Minor Marriages in Taiwan  Arranged marriage  Betrothed prospective bride adopted by grooms family during infancy  Those who were adopted very young – fertility rate not very high  Over 9 when adopted – fertility rate greater  divorce rate is low  Suggests that if you grow up with someone you tend not to be sexually attracted to them Sexual Selection  Why are the sexes so different? – Males are generally limited by mate acquisition  Males of most species are generally indiscriminant  Only contribution they make is the sperm, making mistakes not that costly o DNA comes out of sperm head – only contribution  Women – eggs are costly; must be careful with decision because it may have an impact on her fitness  female choice; inter-selection o Costly to create gametes  Intra-Sexual Selection  Inter-Sexual Selection  Anisogamy – morphologically dissimilar gametes But what if there is significant parental care? What limits reproduction when more than gametes are invest?  Parental Investment – investment that increases offspring survival at a cost to the parents ability to invest in other young  Usually: Female parental investment > male parental investment  Female reproductive success is limited by their ability to raise offspring  Male reproductive success limited by access to fertilizable eggs  Sexual selection usually acts more strongly on males o More male-male competition (access to mates) and ornamentation – female choice  Intra-Sexual Selection – within sex competition for reproductive access (usually male-male competition)  Female elephant seals are much smaller than male elephant seals – females do not have strong selection acting on them  Male elephant seals can have a harem of 80 females if successful o Some never father a pup; o Others father many  Harbor seals are about the same size – successful have one mate  Seahorse – male seahorses give birth; egg injected into male brood pouch, male injects sperm  Pipefish – close relative of seahorse; same mating system (male has brood pouch, female lays eggs in pouch, male cares for eggs) o Male eggs brooding takes 2 times longer than the time for a female to produce a clutch of eggs o Male investment > female investment o Male pipefish are coy and choosey  Basis of female body language – prefer larger females; larger can lay more eggs than smaller  can lay all eggs at once and make more offspring  Males like females with large ventral flaps Homo sapiens are sexually dimorphic  What limits human reproductive success?  Human Records in Reproductive Success o Moulay Ismail (the blood thirsty)  Emperor of morocco fathered 888 children o Woman had 69 o Scale of likelihood of intercourse  Minus values mean “not so hot” on intercourse  Positive means “maybe/yes”  Difference between male and female – males are more willing early on  Interesting =- sexes converge over long term  Mend tend to desire more “partners” than women do o Pattern is cross cultural – males have greater interest in having more partners than females  Women fertility curve peaks earlier than men  Men have a plateau earlier than women  Men that are successful with having kids happen later on in life Age-specific fertility rates give the probability of producing a child at particular ages. !Kung women have their first child between the ages of 15 to 19 and the highest fertility rate in their 20s. Women’s fertility falls to zero by age 50. !Kung men do not begin to reproduce until their early 20’s, and their fertility rates are fairly stable in their 30s and 40s, dropping to low levels in their 50s  Men generally favor traits that indicant youth (childbearing potential)  Women generally favour traits that indicate resource acquisition capabilities (resources) Mate preferences by sex a) In personal, advertisements, all but the youngest men state preferences for women who are younger than them. As men get older, the age difference between themselves and preferred mates increases b) Women typically prefer men who are somewhat older than themselves, and these preferences remain the same as women get older o As males get older, their range of interest in the opposite sex drops (rather younger wives) – don’t want to accept anyone as old as they are  Females as they get older – do not particularly care about having younger males, rather older males (older males have greater resources)  How chastity relates to sexes Culture accounts for substantial variation in mate preferences. The average ratings given by men and women in several countries surveyed are shown for a) the trait with the highest interpopulation variability (“chastity”) b) the trait with the lowest interpopulation variability (“good financial prospect”) o Between Sweden and china there are great differences o Chastity – lack of premarital sex (not infidelity during marriage) o Women are more concerned about having a husband with financial prospects – men provide resources, women are better able to produce young when they are younger March 14 Sexual Jealousy  Forces choice surveys indicate that: o Males are most concerned about sexual infidelity  If the female has a child with another man, they will have to help raise another mans child o Females are most concerned about emotional infidelity  Male is the support system; they need the man  When asked “how much they focused on each type of infidelity” the sex differences disappeared in one study but gained support in others  More current research supports the human sex differences in jealousy but indicated individual differences among members of the same sex may be great  Ongoing research attempts to resolve the differences in results on human jealousy o Among Hadza people, Grank Marlowe found that:  When men’s mating opportunities (abundance of eligible women) were low they invested more time caring for their genetic offspring  When eligible women were abundant, less time spend caring for genetic offspring Patterns of parental care and genetic relatedness  Some evidence suggests that genetic relatedness is important in decisions about parental care  Hadza – see text o Used police records of child murder – not subject to bias of surveys o Very few children are killed by natural parents o Many more young children have been killed when living with one natural and one step parent o Happens very rarely in context  Culture is an adaptation that is shared with our common ancestors and seen in other primates  Culture allows humans to exploit a wide range of environments o One chimp population puts a vine down a termite mound and slides vine through mouth to each termites o Another chimp population might use a stick to collect termites and pick them off and put them in their mouth o Methods consistent within populations o Cultural evolution – copying, social learning spreading throughout population  Culture allows humans to explain a wide range of environments  Certain features of culture that leads to expansion of our range o Eg/ Inuit person hunting green mammals using kayak and harpoon  People able to live far north along with Norse folks  Norse did not pick up on Inuit culture – Inuit able t develop in harsh environment while Norse died out  Inuit people out-lasted the Norse living on Greenland because of their culture that developed in the same environment  Norse did not learn from the Inuit and died out because of shortage of food amidst an abundance of food that could have been hunted  Culture o Information stored in brains that is acquired by imitation, teaching or some other form of social learning that is capable of affecting behaviour or some other aspect of the individuals phenotype  Meme o A unit of cultural information (belief or value) transmitted by imitation or learning (R. Dawkins) o Culture spreads through the survival and persistence of memes in a form of cultural evolution o Some memes may not be adaptive – not all memes lead to increased fitness  Eg/ Rock climbing Ecology  Eco = house or abode  Logy or ology = body of knowledge or collection  Ecology is the study (collection or knowledge of the environment and how organisms interact with it  The environment can be divided into o Abiotic – compromised of non-living attributes  Eg/ substrate, humidity, temperature, wind etc. o Biotic – comprised of living attributes; living organisms that make up the habitat in which the organism live  Including competitors, predators, prey etc.  Biotic environment includes conspecifics Canada’s Most Biodiverse Habitats  Wetlands  A) Bogs are stagnant and acids o Lack nutrients o Unproductive habitats o Carnivorous plants  Eg/ Sundew plant, fly goes near plant, fly stuck to tips of plant, plant slowly closes around fly – fly breaks down, plant gains nutrients from fly  Small points with downward facing spines, fly dies in water, water goes into plant and plant absorbs nutrients from fly o Wainfleet Bog o Quaking Bogs  Sort of like a water bed  B) Marshes have nonwoody plants o Productive – no trees o Cootes Paradise Marsh  Estuaries – river flows out of fresh water source into the sea o Productive marine environments o Dropped off in the delta  Tropical Wet Forests – extremely rich in species; Biodiverse o Temperature  High  Does not vary much o Precipitation  High rain fall (precipitation)  Variation is high – rainy season and dry season  Plants need to be able to survive with both high and low rainfall  Subtropical Dessert o Temperature  High  Moderate Variation – does not go below freezing but can get cool – variation as a function of season o Precipitation  Low amount of precipitation  Low variation o Saguaro cacti are a prominent feature of the Sonoran Desert in the southwestern part of North America  Temperate Grasslands o Temperature  Moderate temperatures  Moderate variation – pretty hot and below freezing o Precipitation  Not much moisture, evaporated and wind gets rid of moisture  Little precipitation  Low annual amount of rainfall (more than desserts) – moderate variation o Not very diverse o Grasses are the dominant life form in prairies and steppes o No trees  Temperate Forest o Temperature  Moderate temperature  Moderate variation o Precipitation  Moderate amount of precipitation  Low variation o Temperate forests are dominated by broadleaved deciduous trees  Arctic Tundra o Temperature  Vey low temperatures  High variation o Precipitation  Very low amount of precipitation  Low variation – desert like in some regard – low availability of moisture) o Cannot withstand wind much and cant get moisture o Lichens and herbaceous plants (flowering plants) o Permafrost - some has began to melt and causing problems o No trees o Dominated by cold-tolerant shrubs, lichens and herbaceous plants  Boreal Forests o Temperature  Low temperature  Very high variation o Precipitation  Low amount of precipitation  Low variation o Needle leaved ever greens – can withstand low temp and low rainfall (absorb moisture through ground and doesn’t evaporate as quickly) o Dominated by needle-leaved evergreens, such as spruce and fir How can organisms interact with their environment?  Evolutionary Adaptation – Long Term – genetically based changes due to natural selection favoring individuals carrying beneficial mutations o Eg/ Evolution of crypsis o Eg/ Scorpian Fish living on coral, matches environment well – natural selection has favoured genetic individuals who match background well – solution if slow change o Global climate has been changing faster (because of2CO ) – not good solution to rapid change environment, lots of species will be left behind and cause extinction  Physiological Acclimatization – Medium Term – metabolic or physiological adjustment within the cells or tissues of an organism in response to environmental stimuli that improves the ability of the organism to cope with its environment o Eg/ adjustment of fish to rising temperature in a body of water  tolerance to high temp increases over time  Three curves of fish that were acclimatized to different temperatures Time-temperature curves of cold-tolerance: Lower median tolerance limits in relation to the time (duration) of exposure to the test temperatures. The specimens were previously acclimatized to three different temperatures (12°, 20° and 28°), indicated on each curve  Behavioural Response – Short Term – behaviours in response to the environment in broad terms o Eg/ Lizards  Will adjust their body temperatures – early morning (cool) will orient body to sun that will keep them warm  Retreat to burrow during intense heat, escape from a predator Major Ares of Ecological Study  A) Organismal Ecology o When hatched out, go to ocean and will live there for a couple of years o Will use celestial cues to find stream and then use scent to track up a stream to find their nesting area – female lays eggs, males drop sperm on eggs o Good at defending nests o Jacks – not territorial, small, hang out in vicinity of nest, when female lays eggs – sneak in and drop sperm on eggs and can fertilize some eggs  less fertilization, but better at surviving (more likely to fertilize because likelihood to survive is higher)  B) Population Ecology o How and why does population size change over time o Eg/ Each Salmon produces thousands of eggs and very few survive at seam how to navigate back home and drop eggs again o Human fishing pressure can affect populations of salmon  C) Community Ecology o Population – groups of same species that are somewhat isolated from others o Community – various population of different species that interact together  D) Ecosystem Ecology o Animals breed once – whole life culminates in getting back to natal stream, breeding and then dying o Leave behind all kind of nutrient – change productivity of area they go to breed o If they weren’t coming back, productivity would diminish Consequences of Human Activities  Mountain Pine Beetle Outbreak – Climate Change  Cheatgrass – Eurasian invasive in North America, transported by humans  West Coast – brown trees, conifers  pine trees that were in the process of dying or already dead – brown needles o Reason – trees are being hit by mountain pine beetles – lay eggs, bore into tree, kill tree if lot of beetles o Pine beetles growing dramatically because of global warming – usually winter kills 90% of beetles, but winters are warmer and pine beetles have been surviving (used to be 10% survive, not 80% survive now) o Lays eggs, population increases, more trees die  Trees uses to be a carbon sink – change carbon into sugar and structure of tree; when the trees die, they fall they rot and release carbon dioxide o Used to be carbon sink  not carbon source  Native pest  mountain pine beetle o Beetles can now attack jack pines  Cheatgrass “cheats” native plants of water in the spring, before Native plants become active o Adds fuel to fires, which increase in frequency and burn hotter o Cheatgrass is adapted to thrive in fire dominated environments, being an annual plant with seeds that sprout effectively in fire depleted soil o Filled in and created biomass that burns o Seeds can withstand fires, native plants cannot withstand fires and will not come back o Cheatgrass does well in soils that are deprived of nutrients due to fires Word List  Population  Community  Ecosystem  Biome  Conservation Biology  Biotic  Conservation Biology  Biotic  Abiotic  Benthic  Littoral  Wetlands  Lakes  Streams  Estuaries  Oceans  Rain Shadow  Biogeography  Invasive Species March 15 Population Ecology  Population – a group of conspecifics living in the same place and time  Spatial element varies as a function of motility of species o High likelihood of interaction with other members of group without having to migrate  Demography o Study of factors and processes that affect the size and age structure of a population over time  Population Size o Count or estimate by aerial counts of large organisms, especially in migration or on breeding colonies, or in nesting colonies o Active nest colonies (colonial nesting birds)
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