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Define theories, hypotheses, assumptions, data, & inferences. - >>>Theories: explains CAUSAL relationships at an ABSTRACT level Hypothesis: deduced from theory (more specific, 2 variables) assumptions: conclusion without evidence data: information of any type inference: conclusion from evidence Darwin's Postulates - >>>1) Population is infinite, but resources are not
- Population varies
- Heritability (variation passed down) Ground Finches - >>>Birds on Galapagos island > Drought > big beaks survived to open big hard seeds > small beaks couldn't compete Postulates: 1) lots of birds, not that many seeds, 2) some small some big beaks, 3) heritable beaks Toxin Resistance in Daphnia - >>>?? Misconceptions about evolution by natural selection (6) - >>>DOES NOT happen at random, does NOT happen at individual level but a population composition, CAN be complex, CAN have rapid change, NOT always a good thing Why is phenotypic variation continuous even though genes are concrete? - >>>becuase each phenotype is not composed of one individual gene - genes determining phenotype can be found throughout range of different loci - phenotype also affected by environment
How does natural selection move populations far beyond their initial range of variation? (chihuahua effect) - >>>Hidden variation within genes - recessive genes are not replaced, just not passed down, but doesnt mean its eliminated 5 constraints on adaptation CDGLL - >>>Correlated Characters (have one characteristic --> leads to another genetically/genes affect more than one character) Disequilibrium (selection takes time to catch up w environment) Genetic Drift (random changes/mutations in gene frequencies) Local vs Optimal (natural selection favors trait atm, but does not look ahead -- most common phenotype may not be BEST phenotype) Laws of physical & chemistry Ring Species - >>>Same species that divulged so far that they are too distant to interbreed but still have some gene flow (result of allopatric speciation) Allopatric Speciation - >>>when population separated by barrier and diverge so far off they become reproductively isolated (process by which you get ring species) Essentialism - >>>idea that if a population changes it is no longer that population population thinking - >>>population is a population despite the ongoing changes - dynamic group of individuals Convergence/analogy - >>>similar traits but no common ancestor - traits bc of environmental adapatations Homology - >>>traits simlairty due to common ancestor
selfish herd (every man for himself) Crypsis (hiding) Cost/Benefit - strategies? - >>>Cost and benefit refer to the effect of particular behavioral strategies on reproductive success. Benefits/costs are measured as changes in reproductive success (currency). Behaviors are beneficial if they increase fitness, or they're costly if they decrease fitness. Tingergen's four level of explanation CDEF - >>>Causation: proximate explanation Development: ontogenetic explanation Evolution: phylogenetic explanation Function: ultimate adaptive explanation Biological Altruism - >>>Benefiting others at cost of yourself to pass down your genes for the greater good -- cost depends on level of relatedness between the 2 Hamiltons Rule - >>>biological altruism beneficial as long as rb > c Conditions for altruism to occur - >>>Opportunities to act often Keeping track of give and receieve Provide support to only those who help themm ex: grooming Parental investment / sex differences - >>>diff time investment/resources --> diff degree of benefit Males do not care for their offspring (1) when they can easily use their resources to acquire many additional matings or (2) when caring for their offspring would not appreciably increase the offspring's fitness.
dominance hierarchy - >>>high ranks get resources, mates male primate morphology - >>>more competition to mate = more sexual dimorphism to attract femaeles (large teeth, etc) female primate variation - >>>dominance hierachy -younger = high rank middle age = most succesful longevity = more fitness high ranking females receive moreprotection and resources and sperm lol!! inbreeding avoidance primate techniques - >>>Westermarck idea (recognizing who you grew up w) staying away from similar phenotypes age: male leaves when daughter turns into breeding age infanticide - >>>kill baby so mom can open up her reproductive cycle early for u naturallistic fallacy - >>>natural doesnt mean good (infanticide) life history traits - >>>- timeline of reproductive cycle -fast/slow life histories depend on the environment and resources avaialble to the species they evolve in bundles bc trade offs - energy is allocated and driven by selection (ex: rats put all energy in reproduction bc short life span so have lots of babies vs priamtes who live longer and have more time and resrouces to raise kid) -TRADEOFFS: growth vs body maintenance vs reproduction, quantity vs quality offsprings, mating efforts vs parental efforts
Compute: # fossil species known/#species that ever lived, Only 3% of all primate species have been found so far -- We are missing 97% of the data -lifespan of species : fossils mislead us about lifespand of a species (how long they all existed) because might find one here and one later but probably cant find the first and the last of any species Fossil Dating Methods 6CUTE PR - >>>C-14 aka Carbon dating Thermoluminescence Dating Uranium-Lead dating Electronic spin resonance dating Potassium-Argon dating Relative Carbon Dating - >>>Using carbon 12 and carbon 14 in fossil and in atmosphere (predictable cycle in atmosphere) to predict when the orgainmsed died by using half life (5,700) downside: can only predict up to 50,000 years (predict recent periods) Clock in a rock/potassium argon dating - >>>can only use on minerals trapping argon - only minerals, not organic materials -- dating volcanic rocks in assocation with fossil material (decay is slower so need to test for things atleast 500,000 years old) thermoluminescence dating - >>>based on high-energy nuclear particles traveling through rock, used trapped electrons in flints by heating in a lab & measuring how much light given off electron spin resonance dating - >>>a technique used to date fossil teeth by measuring the density of electrons trapped in apatite crystals in teeth - To estimate the number of years since the tooth was formed, paleontologists must once again measure the flow of radiation at the site where the tooth was found.
uranium-lead dating - >>>A method of dating zirconium crystals in igneous rocks that is based on the ratio of uranium to lead relative dating - >>>Method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock Red Queen Hypothesis & climate change - >>>Rather than envision evolutionary change as progress toward perfection in a static environment, think of it as a response to environmental change: often, change is the only alternative to extinction. The climate has changed substantially during the last 65 million years—first becoming warmer and less variable, then cooling, and finally fluctuating widely in temperature -- species adapting to that, not nesssecarily adapting to be the "best" (Ex: blind cave fish) -- pangea determined climate (larger continent, more extreme climate) -- animals adapting to these climates Primate fossils - >>>Grasping hands and feet Nails instead of claws Forward-facing eyes encased in bone Hind limb-dominated locomotion relatively large brain Generalized teeth ¨ 2-1-3-3 maximum formula Bipedalism traits - >>>Short pelvis
kill sites had bones with marks of carnivore teeth impacts and stone tool impacts (cut marks and bite marks) -- both seen on all parts of prey (not just cut marks on left over pieces like skull, but evidence of cut marks on meatier pieces that a scavenger wouldn't have had) Homo Sapiens and DNA - >>>mitochondrial DNA passed from mother and can be used to see if 2 organisms have same ancestors (recosntruct evolution) Y chromosomes passed down from father to son Both DNA supports the "out of atrica mdoel" -- denisovans and neanderthals are closetly related to each other more than they are with modern humans eurasian homo sapiesn interbred with neanderthals and denisovans contemporary non-africans: no neanderthal genes The mtDNA of every person on planet can be traced back to a single female u The Y chromosome of every man on the planet can be traced back to a single male Heritability - >>>used to estimate the degree of variation of a PHENOTYPIC TRAIT in a population due to GENETIC VARIATION (not environment) 1 -tells you about the SOURCES of variation AMONG individuals, NOT about the relative roles of genes & environment (cake analogy: genotypes are recipes and environments are like ingredients | At every moment during the baking of the cake, both the recipe (=genes) and the ingredients (=environment) are involved, and they're completely intertwined; there's no way to separate their contributions) 2 heritability tells you about the trait in a certain population at a certain time -- can change as genetic variation within populations change 3 A trait's heritability tells you nothing about the sources of phenotypic differences between groups that live in different environments
Many traits influenced by many different genes u Example: Height u Bell-curve distribution u Heritability (proportion of the phenotypic variation that's due to genetic variation) u Environmental covariation Vg___ Vg + Ve Genetics vs Environment: - >>>TWINS: If variation has a genetic origin, monozygotic (identical) twins are likely to be more similar to each other. If variation is due to the environment, then monozygotic and dizygotic twins (Fraternal) will be equally similar. Phenotypes are also environmental - shorter ppl live in tropics, taller ppl in colder The fact that variation within populations has a genetic component does not mean that differences between groups are caused solely by genetic differences. Sources of Genetic Variation in Humans (within group) - >>>1) Selection-mutation balance Mutation can maintain deleterious genes in populations, but only at a low frequency. Many diseases are caused by recessive genes. For example, only people who are homozygous for hemoglobin S are afflicted with sickle-cell anemia. All these diseases are caused by mutant genes that
different from each other than are the "average" genotypes of any two nations on different continents human diet before agriculture - >>>hunting big game/gathering/foraging (more protein, less carbs) 70% of our diet was not available back then (more poly-unsaturated fats) -- refined grains, dairy products, vegetable oils, refined sugars, high fructose corn syrup) why are learned behavioral patterns products of natural selection? - >>>The potential to learn behavior patterns can be seen as an adaptation necessary for survival Ex:rats quickly learn to avoid new foods that make them ill. This learning rule is due to rats living in a wide range of environments where they have to forage and constantly eat new food. men vs women on spatial ability - >>>women - object location tasks good bc of gathering skills men - 3d spatial rotation of shapes good bc need to track moving targets from hunting conditional rules - >>>The Wason Selection Test was designed to test people's ability to detect violations of conditional rules: If p, then q (rule violated when p is true yet q is false) Cognitive psychologists had discovered that people's ability to detect violations depended on the content of the problem, even though the logical structure was always the same: % of subjects answering correctly varied from 20-80% depending on content There was no clear idea about why people's logical reasoning abilities were content-dependent Cosmides(1989),using evolutionary theory, hypothesized that * people have special-purpose mechanisms for reasoning about (ancestrally) adaptively relevant problems, such as "Look for cheaters" in social exchange situations; people generally don't use the abstract rules of logic unless they've been trained in them* Also mental modules for taking safety precautions Context of the problems help us solve the problem if it had something to do with our evolution
Westermarck Hypothesis and evidence in humans - >>>The Westermarck hypothesis for * inbreeding avoidance states that individuals who are co-reared together (raised together as kids) are less likely to be attracted to each other in the first place ---an adaptation to avoid inbreeding Taiwanese minor marriages: children are given to husbands household as early childhood Bride and groom had lack of sexual interest Low fertility More infidelity More divorce Earlier the women were adopted at later ages, the less fertile they were Kibbutzim: unrelated children co-reared from early childhood never married or become romantically involved Nuerobiological-endocrine mechanisms in mating vs parental effort in human males - >>>Males shift energy allocations over their lifetime human males show signs of hormonal adaptations for facultative paternal care: socioendocrinology of fatherhood Prolactin: involved in mammalian maternal care, expected to be postively related to paternal care (high after mates give birth, to take care of kids, more time with infant = more prolactin and less testorone hehe) Testosterone: promotes intra-sexual competitiveness - expected to be negatively related to parental care -- low testorone = more care, more testosterone = less parental care (low after mates give birth) Personality variation in humans (2 hyp) - >>>Balancing Selection* -Trade-offs between the costs and benefits of having certain personality traits e.g. a study in Britain showed a positive correlation between Extraversion and number of sex partners, but
sex differences (and similarities between the sexes) in human mate choice criteria and attributions of the opposite sex's sexual/romantic intention - >>>men: love younger, more fertile women, more sexual partners, good looks women: men with money, resources both: get along with other person, compatibiltiy, agreeableness Language based on speech production, perception, grammatical competnce, and TOM - >>>speech production: anatomy of vertebral column allows control of breathing while shape of hyoid bone makes vowel sounds speech perception: you can perceive speech much faster than you can other sounds grammatical competence: deaf children learn and make up their own grammar/don't need to be taught TOM: to communicate, TOM abilities needed to cooperate w each other culturally transmitted information - >>>culture allows us to accumulate better strategies for exploiting local environments Social facilitation: the activity of one animal increases the chance that other animals will learn the behavior on their own
- e.g. by exposure to the relevant materials Observational learning (imitation): naïve animals learn how to perform an action by watching the behavior of experienced, skilled animals Emulation: naïve animals learn the end state of the behavior, but not what behavior generated the end state (they learn the behavior itself by individual trial-and-error learning) human capacity for culture - >>>To summarize: the human capacity for culture evolved from simpler social learning abilities that we
see in other animals including nonhuman primates...One aspect of human uniqueness is our ability to quickly acquire behaviour that's far too complex for any one individual to learn by trial-and-error difference between cultural evolution and genetic evolution - >>>genetic: cant change, get it at birth culture: can change whenver you want, can get it from anyone (media, etc), can be harmful and common Cooperation in humans vs cooperation in animals - >>>Humans are ultrasocial or "hypersocial" - cooperate in large groups that include non-kin
- This is obvious in complex societies: e.g. donations to charity, voluntary military service
- But it's true in all human societies, including huntergatherers... Experimental Economics Results: People don't behave as predicted by the model of self-interested Economic Man People also punish, at some cost to themselves, people who violate fairness norms in their conduct toward others: 3rd Party Punishment
