Completed Life Science 15 Final Review PDF

LIFE SCIENCE 15 FINAL REVIEW LS15 Important Post-Midterm Topics Question topics: ○ Topic One: Happiness / emotions ○ Topic Two: Mismatch / technology influences on out biology ○ Topic Three: Neurons and drugs ○ Topic Four: Hormones...

LIFE SCIENCE 15 FINAL REVIEW LS15 Important Post-Midterm Topics Question topics: ○ Topic One: Happiness / emotions ○ Topic Two: Mismatch / technology influences on out biology ○ Topic Three: Neurons and drugs ○ Topic Four: Hormones ○ Topic Five: Mating and reproduction ○ Topic Six: Nutrition and macromolecules ○ Topic Seven: DNA fingerprinting General exam information: ○ Will have a short answer question on 6 out of 7 of these topics ○ 22 mc questions (roughly) are post midterm ○ Focus on lecture notes ○ Talks about things that he thinks are most important ○ If you could write a nice essay about everyone of the 36 questions, you could potentially ace the exam Topic One: Happiness / emotions 1. Why is the rate and direction of change in your financial situation more important than your absolute level of wealth when it comes to happiness? Core of this idea: emotions are tools that your genes use to manipulate your behavior. But because of that they are not responded to at an absolute level. They are responding to changes? The emotion of happiness is a tool our genes use to induce us towards behaviors benefiting them Evolution is a relative game. Alleles that win are those that do better than its alternatives We think that achieving goals will make us happy, but it is truly the progress toward the goal that makes us happy. Absolute levels actually have little effect on happiness Material acquisitions: level of well-being does not increase with annual income. In fact, this is typically an inverse correlation ○ Anthropologist that went to an undeveloped village, and the village broke into his stuff and took the material gifts ○ Acquisitive desires exist cross culturally Rich people are no happier than poorer people Evolution is a relative game → the alleles that do better than the alternative allele win Absolute values have very little effect on happiness  We love making progress Expectations play a central role 2. Why are emotions less permanent than they feel? Bc purpose is to motivate you But once genes have done that, they have to be able to use them again in order to be an effective tool Emotions are brain states designed to alter our behavior, once we reach our goal our happiness fades We think they are going to last forever, because their purpose is to motivate you, because they seem like a great incentive, but because their goal is to motivate your behavior to change your behavior, once your genes have done that, then, in order for them to be an effective tool, it has to be able to do something else (we have to be able to use them again) 3. Describe three lines of evidence supporting the idea that emotional happiness are tools that our genes use to manipulate our behavior. If they are just tools to manipulate behavior if something really good happens, you should feel really happy but then they should reset themselves Victims of accidents (people who survive catastrophic accidents) Lottery winners One line of evidence: they are just tools to manipulate their behavior, so if something really good happens, you should feel happy, but then it they should reset themselves (so those feelings of happiness should settle down) People are much happier after the win the lottery, but then it comes back Topic Two: Mismatch / technology influences on out biology 4. Using two examples, explain why human culture reduces the usefulness of our instincts. We reach sexual maturity and we become interested in having sex. However, the culture we are in typically frowns on you having kids at fourteen (or younger). Instincts to consume food because you’re not always going to have access to it due to our beginnings in a hunter gatherer society. However, now because of agriculture and industrialization we no longer have limited access to food but our instincts tell us to eat as much as we can, so people become overweight. And since we live in an industrial world we do not have to search for food on foot, which limits our fitness and contributes to issues regarding weight. ○ Agriculture: large-scale farming of crops  ○ Horticulture: smaller-scale gardening ○ Pastoralism: raising live-stock ○ Industrialism: a social or economic system built on manufacturing industries Agriculture and industrialization 5. What is the fundamental reproductive equation and what does it reveal about culture and biology? Sex = Pregnancy = Babies = Maternal Child Care = Loss of Female Economic Opportunity = Loss of Female Political Power ​Condoms allow sex not to equal pregnancy ○ Biological instincts don’t have to lead to a loss of female political power Abortion allows pregnancy not to equal babies Rubber baby bottles allow babies not to equal maternal child care Day care allows maternal child care not to equal loss of female economic opportunity ○ Pay someone else to take care of your kids ○ Gain economic welfare ○ Because of rubber too Everyone is able to vote, whether you are rich or poor allows loss of female economic opportunity not to equal loss of female political power ○ Culture saying biology shouldn’t dictate outcomes you get ○ Culture undermining fundamental reproductive equation Culture can free us from out biological constraints and make equality possible 6. Using two examples explain what constrained learning is and how it illuminates the culture biology plays. You can’t learn everything. Sauce bearnaise phenomenon ○ A certain thing happens and you want to make a connection. You ate these things and got sick, even though it wasn’t the cause of you getting sick. Example: rat study ○ Can learn that when drinking water, noise and lights will be followed by an electrical shock ○ OR drinking water will lead to a weird taste will induce nausea ○ HOWEVER the rats can’t learn that drinking water followed by a weird taste will lead to an electric shock ○ OR drinking water followed by noise and lights will lead to nausea ○ Rate have a “genetically coded hypothesis” for “if I feel sick it must be something I ate”  ○ This shows us that our biology constraints our learning for certain things, not allowing culture to shape our behavior ○ It is really easy to learn some things and harder to things which were not a part of our EEA “Sauce Béarnaise” effect: a conditioned taste aversion for certain foods that were eaten and followed by illness. This is an adaptive mechanism to protect oneself from future poisoning. Many times the sickness is completely coincidental and not related to the food, but we learn to avoid the food anyway ○ Phelan’s beef wellington example ○ His mom made it and he threw up so now he will not eat it again ○ Prepared learning eliminates the leash of biology reining in cultures' ability to shape our behavior. 7. What is the EEA? And why is it important for us to be aware of it? EEA: Environment of Evolutionary Adaptiveness ○ (Culture) ○ (Technology) ○ Unpredictable food ○ Small populations ○ Hunter-gatherer: men hunt, women take care of kids Today’s environment is very different from our EEA. We are no longer hunter-gatherers living in small communities. Because of culture and technology, we can’t trust our instincts. We need to be aware of it so we can alter our behavior accordingly. With readily available food, we can eat whenever we want. Our instincts insist that we eat the calorie ridden fats, and as much of them as possible, leaving us subject to obesity and other health related problems Birth control reduces the cuckoldry risk, but sexual jealousy persists because we were evolved to have these feelings in order to protect our reproductive success. We don’t have the capacity to produce our own: food, medicine, shoes, contact lenses, houses, sanitation systems. Natural selection is really good at adapting us to our environment There is a mismatch every time the EEA and environment don’t match up 8. Why is the EEA sometimes different from our current environment? (come up with a couple of reasons)  (example) Culture allows very fast change of our environment, while evolution remains a slow generation by generation change Culture Technology ○ Changes in the environment really quickly ○ Not always changing at a constant rate We are dependent on other people to grow our food, build our homes, and many other things ○ Good is not difficult for us to get ○ Hunter gatherer communities did not have this luxury We have massive agriculture with readily available food, and we generate power and electricity We are money-centered and can not provide many things for ourselves without it ○ Reduces are reliance on others Our culture and ideas change our environment rapidly, and we have not been able to adapt yet Firearms reduce need for strength Armies can fight our battles (additionally) Environments change quickly. ○ We are adapted for a hunting-gathering environment but we live in a modern, industrialized society. Adapted for unpredictable food sources, small groups, and movement ○ There is a lag time in evolution so we are not adapted to our current environment; takes many generations for evolution to keep up ○ If environment changes quickly (which it does because humans are so good with technology), natural selection can’t keep up, which causes mismatch Leads to impacts: obesity, cuckoldry (females have lots of mates so 9. Describe three examples of species having different EEA than the current environment. (realistically come up with ten) Animals in the zoo ○ Evolutionary perspective: bred an environment where they have to fight to survive, hunt for food ○ Zoo: animals are given free food and they are protected so they don’t have to fight to survive Teenagers in modern industrial society ○ When biology/your body tells you have sex and kids versus when society says it’s okay for you to have kids ○ When your body is ready to have kids versus when you want kids  Dogs being kept as pets ○ Schedule when they eat and protect them from danger → can lead them to becoming fat Squirrels on ucla campus? (fed from food in vending machines and they get fat) Astronauts in space Months flying into glass Animals in medical research labs that get free access to food 10. What does mismatch mean? What are its implications for our instincts? Mismatch: difference between current environment and EEA ○ our behaviors have evolved in a different environment and its not as useful anymore, maybe even maladaptive (not evolutionary adaptive) ○ → our instincts are unreliable Instincts: we can’t trust them anymore (examples) ○ Our EEA had us eating in preparation for famine, therefore eating as much food as possible, with as many calories as possible (fat). We tend to overeat and eat unhealthy now, because of this, with readily accessible food ○ Birth control reduces the cuckoldry risk, but sexual jealousy persists because we were evolved to have these feelings in order to protect our reproductive success Just because it feels good doesn’t mean it is going to lead you to the best outcome ○ Cocaine – stimulating the “do it again” feeling – which obviously is not the right thing to do Example: Exercising ○ In the EEA, hunter gatherers had to walk everywhere and hunt to get their own food so they were exercising naturally without even realizing ○ Now in our current environment we drive everywhere and sit in desks at work all day long ○ We now schedule specific time to workout in our daily routine Topic Three: Neurons and drugs 11. Why is it hard to be a teenager? Be specific (but not too specific) Not hard everyone Society that is still living as hunter gathers → it wouldn’t be problematic Industrialized world → discrepancy between when you want to have kids and when your body/biology says to have kids Instincts don’t really add up  ○ When our bodies tell us to have sex and when it's socially acceptable to begin having kids ○ Start having sex at ages 15-18 and have kids mid twenties to early thirties Instincts only apply to hunter gatherers Culture now alters our instincts Due to mismatch! The age of sexual maturity is far from the age of our wanting children. Culture wants us to hold off on having sex, but our instincts are in conflict with this. Body wants sex, culture says no 12. Describe three other examples of conflict that humans experience due to the alien nature of our world. (really ten) 1. Obesity ○ It’s conflict because in many cases people want to weigh less they do, but instincts tell us to eat when we have food (because food was scarce and our instincts prepared us for that, but then we evolved and now food is scarce) 2. Drugs: cocaine ○ The first time they do it they think it’s fine. But at some point they may think they rather not be doing this. It is interfering with my performance in school. And it becomes hard to not do it 3. Food distribution system ○ Eat as much fats as money can buy ○ Calorically dense (1g = 9 cals) That’s why we like the taste 4. Birth control ○ Cuckoldry/cheating was a real risk 5. Day care ○ Females don’t have to be with babies 6. Having children at 24-27 years old: ○ Sexually mature over a decade earlier ○ New conflict: society says don’t be sexual, biology says be sexual 7. Firearms ○ Available for everyone, at a low cost ○ Physical strength is not as important Sex differences are less important 8. Army service: ○ Why do thousands of men join?  ○ Are they altruists? ○ Why are some ideas so powerful? Other: How has our environment become “alien” to us? ○ We don’t have the capacity to produce our own food ○ We don’t have the capacity to produce our own: Medicine Shoes Contact lenses Houses Sanitation systems CHAPTER TITLES IN MEAN GENE ○ Debt ○ Fat ○ Drugs ○ Risk ○ Greed ○ Gender ○ Beauty ○ Family ○ Friends 13. Describe the organization and functionalization of the nervous system. You have the central nervous system and the peripheral nervous system. Peripheral nervous system ○ Part of it is sensory ○ It is detecting sounds that are out there or smells or sights, or just all these things that are physical pressures. You detect what is in the world ○ The information that you just detected for what’s in the world, goes to your spinal cord and up into your brain. (then comes the role of the central nervous system) Central nervous system ○ Stores the memories of every situation you’ve encountered, other things you know, as motivators demotivators. ○ It decides how to respond to this and then back to the peripheral nervous system Peripheral nervous system ○ Back to the peripheral nervous system, but the MOTOR CONTROL part. It allows you to control your muscles, so that you can run away, move towards something, or eat it, or punch it… whatever seems appropriate  But it’s TWO SEPERATE things ○ The way you can have knowledge and memory(s) and they can be stores in a safe place ○ And you can get information and act on it 14. What our senses all have in common (in terms to how they all help our body respond to the external environment) They're all modified dendrites specialized for responding to external stimuli by initiating action potential and convey information to the brain No matter which sense it is, somewhere on the sensory neuron there is a modified dendrite that has a receptor that responds to a force ○ The force might be soundwaves, light energy, physical force, chemical interaction, etc Definitions to know: ○ Dendrites: A short branched extension of a nerve cell, along which impulses received from other cells at synapses are transmitted to the cell body ○ * Photoreceptors: specialized cells located in the retina of the eye that convert light into electrical signals, essentially allowing us to see by transforming light into a form the brain can interpret ○ * Chemoreceptors: Specialized cells that detect changes in the chemical composition of blood and the environment. They are responsible for maintaining homeostasis by regulating the levels of oxygen, carbon dioxide, and pH in the body There are different things that they respond to but if you think about it in every case there is some kind of force that results/opens a sodium/ion channel allows the action potential to start and works Any sensory system that we or another species have is part of the nervous system and is an element of the nervous system in which the external stimulations sends a signal to the brain allowing you to integrate to what you know → if relevant to generate some kind of response Whether it is hearing, seeing, touching, smelling, etc → the initial interaction between the stimulus and the nervous system differs → when it goes to your brain they are all the same OUR SENSES ARE ALL VARIATIONS ON A THEME: cells responding to physical or chemical stimuli by opening channels within neurons and stimulating or blocking action potentials ○ There is a physical or chemical stimulus → causes signal (that brain can receive) → opens channels (most of the action potentials) → action potential goes → action potential sends signal to muscle telling it to contract  ○ Example: smell (roast beef) – roast beef chemicals cause the sandwich to smell → in the membrane you have dozens of different shaped receptors (exactly conformed so a certain chemical can bind to it): when you have chemicals that bond sodium channels open up → sodium rushes in → potassium out → after linkage of chemicals, you then smell the roast beef ○ Example: taste– taste buds are neurons that stimulate the brain message of what you are eating 15. Describe an action potential. Which part of the process accounts for most of the energy used? Review section explanation: ○ Sodium channels open and sodium rushes in because there is more of it outside than inside. The idea of the concentration rating is really important to how the nervous system works. You send it up when it is ready to be used. There's way more sodium outside than inside so all you have to do is open the door. It all rushes in and it doesn’t take any energy to do that. ○ Then potassium came up, they opened. And because there is a concentration gradient, there is more potassium inside then outside, they rush out. ○ So first you have these positive charges coming in, the charge goes away, then you get rid of a bunch of different kinds of positive charge and it goes way back down. That's what that spike looks like when you plot/graph it. That doesn’t take any energy either because there is more potassium inside than outside, and then what happens? ○ To get ready to fire again, you gotta go back to the original condition, so you have to take a pump and push all the sodium where it doesn’t wanna go. It doesn’t wanna be all concentrated and all packed into the outside area. It wants to be even with the two. So that takes energy. ○ Taking the potassium ions produced, rushing out and moving a bunch of them so there’s more inside. ○ That takes energy to, It’s the same motor that does all that, and it takes a huge amount of energy That’s why our brain for the size that it is consumes way more energy ____ another organ in our body. How he would ask the question on the test: ○ The brain uses more energy than any other human organ. And about 2/3 of the energy used by the brain is to fuel action potentials. Describe an action potential and which part of the process accounts for most of the energy used. In your answer include a graph indicating the electrical changes that occur during an action potential and describe what is responsible for these changes  1. What is an action potential? An action potential is a self-propagating, all-or-none change in the membrane potential that travels down an axon. The three components are depolarization, repolarization, and the resting state. 2. Which part of the process of generating action potentials accounts for most of the energy used? Describe the movement of the ions. The most energy used during action potential is during the restoring of the resting membrane after an action potential. The sodium-potassium pump is working through the process, 3 sodium ions (Na+) move out of the cell and a potassium ion (K+) moves into the cell Stages: 1. Resting state ○ Na+ and K+ channels closed. ○ Some leaking of both 2.Depolarizing state ○ Open Na+ channels; keeps K+ closed ○ Na+ rushes in ○ Cell becomes positive 3. Repolarizing state ○ Closes Na+ channels; open K+ channels ○ K+ rushes out ○ Cell becomes negative again 4. Return to resting state ○ Na+ and K+ channels closed ○ K+ pumped out ○ Na+ pumped out 3. Graph indicating the electrical changes that occur during an action potential  Threshold: ○ Threshold potential is the membrane potential value at which an action potential is triggered in a neuron. When the threshold is reached, a large number of sodium channels open, allowing positively charged sodium ions into the cell. This causes the neuron to depolarize, and the membrane potential reaches zero and then becomes positive. This is the rising phase of the action potential Hyprolorization: ○ A change in a cell's membrane potential that makes it more negative, which makes the cell less likely to generate an action potential Overshoot: ○ a phase of an action potential when the membrane potential of a neuron becomes positive, exceeding its resting potential 16. What is the myelin sheath and how is it related to development and disease? Myelin Sheath: protects and insulates the axon, allowing signal to propagate more quickly (fatty coating) Development: babies have underdeveloped myelin. They can’t walk because they can’t send the signal to ○ They understand the concept and send the signal, the signal just never reaches the muscles Disease: multiple sclerosis (MS) (many scars) is when the body attacks the myelin, causing it to scar. Now they can’t serve as insulators and the signal can’t propagate properly so they lose control of their hands, legs, etc. ○ Gradually breaks down myelin ○ Lose control over muscles An action potential is an all or nothing change in the membrane potential Less myelin, less ability/control over muscles → very problematic Nodes of Ranvier → space in between myelin 17. Using an example describes how drugs influence stuff at the synapse. (gave eight examples in class) Can block NT release, over-facilitate NT release, increase/decrease NT breakdown in synaptic cleft, or block/facilitate binding to receptors. Drugs interfere with normal neuron functioning, changing the way we feel and function  Our brain is built with pleasure centers. When we stimulate them, we want to do it again. Drugs, however, can hijack these centers and provide the same feelings w/out doing the work. Ex. Morphine->endorphin rush. They can't distinguish between false and real highs. Serotonin affects appetite, sleep, anxiety, and mood ○ Makes you content and satisfied Example one: caffeine ○ Caffeine: over the course of a day, adenosine (cellular exhaust) builds up in brain synapses, filling receptors and opens ion channels making cells less likely to fire. This makes us tired and slows brain activity. When you sleep, it is reabsorbed. Caffeine acts as adenosine, but doesn’t make the neuron less likely to fire. It is a better fit than adenosine and can actually bump it out of receptors to prevent it from inhibiting brain activity, making you feel alert and less tired. Can help athletic endurance and learning. More adenosine the more tired you feel When you sleep the adenosine goes away The caffeine can kick these adenosine out and keep you awake and alert The more caffeine you intake, the more receptors your body acquires, meaning more caffeine is required to have the same awake feeling Example two: ecstasy ○ Ecstasy: increases serotonin production and blocks serotonin reuptake. This permanently damages serotonin producing cells in the cerebral cortex (learning) and hippocampus (memory). Action potential arrives at terminal button, serotonin blocks the reuptake valves, the vesicles fuse with the membrane and the neurotransmitters are released into the synapse and cannot go up the reuptake valve and more neurotransmitters enter the synapse Example three: botox ○ Botox: blocks calcium channels from opening so neurons cannot fire and muscle becomes paralyzed Muscle is paralyzed and can smooth out wrinkles Example four: SSRI’s/Prozac ○ SSRI’s/Prozac: blocks serotonin reuptake transporter proteins to stop depression. Serotonin makes you content and satiated when it accumulates in the synapse Example five: cocaine ○ Cocaine: binds to dopamine reuptake receptors and blocks them to keep dopamine in the synapse and intensifies pleasure Example six: alcohol  ○ Alcohol: alcohol binds to the GABA receptor, which keeps it open for longer and more Cl- ions enter the postsynaptic neuron Almost all drugs work by affecting the synapse By interfering with normal neuron functioning, drugs can change the way we feel and function (for better or for worse) 18. Explain how adenosine build up causes the need to sleep. Where does it come from? How does it build up? How does caffeine interfere? (what evidence supports that it works) (example) Rodents get better at learning mazing (example) Learning increases (example) College rowers performance increases when drinking caffeine It is getting produced as a byproduct (Phelan calls it) → cellular exhaust. It binds to adenosine receptors in the postsynaptic cells. Causes them ___ sodium so that you can’t create concentration gradients. So still/now how are we gonna know how to respond to stimulation Caffeine interferes by bumping out the adenosine and taking up residence in that receptor, not moving, but not (taking in) force to sodium ions So now you keep working even tho you produced a ton of adenosine and your body should be going to sleep so that other stuff can happen (cellular movement and stuff) Evidence to support that it works ○ Learning increases ○ Rodents get better at learning mazes ○ Physical performance improves College rowers 19. What is the process by which we metabolize alcohol? Why do some people have an unpleasant reaction to alcohol? What are the effects on the brain? Fast flushing/slow flushing (alcohol flush reactions) ○ Is a type of alcohol intolerance that can cause: facial redness, nausea, headaches, and increased heart and respiration rate ○ The speed at which someone's face flushes after drinking alcohol depends on their metabolism and the amount of alcohol they consume: Metabolism: People with a faster metabolism tend to eliminate alcohol more quickly than those with a slower metabolism. Alcohol consumption: Drinking alcohol quickly can cause more noticeable flushing How we metabolize alcohol  ○ 1. Liver breaks down the alcohol molecule (ethanol) using alcohol dehydrogenase, which converts it into acetaldehyde (a toxic substance) ○ 2. Acetaldehyde is broken down even further by another enzyme, aldehyde dehydrogenase, which converts it into acetate ○ 3. Acetate is eventually converted to carbon dioxide and water and is eliminated from the body through breath, sweat, and urine Why can we metabolize alcohol at all? ○ Our intentional bacteria produces ethanol (but in small amounts) Unpleasant reaction ○ “Some people have an unpleasant reaction to alcohol because of a genetic variation that prevents their bodies from properly breaking down alcohol, specifically due to a deficiency in the enzyme aldehyde dehydrogenase (ALDH), which leads to a buildup of toxic acetaldehyde in the body, causing symptoms like flushing, nausea, headaches, and rapid heart rate, even after consuming small amounts of alcohol; this is often referred to as "alcohol intolerance’ Effects on the brain ○ 1. Alcohol reduces anxiety GABA is an inhibitory NT docks cells won’t fire. Releasing it calms you down Alcohol mimics GABA, enhancing it’s efficiency ○ 2. Alcohol produces stimulated energized feel Dopamine makes up happy Dopamine increases dopamine levels ○ 3. Alcohol blocks pain Endorphins block pain messages Alcohol stimulates end release ○ 4. Alcohol decreases depression Serotonin makes us content Alcohol increases ser receptor activity ○ 5. Alcohol slows you down Geotamate is an excitatory NT Alcohol blocks receptors: slow/slurred speech Topic Four: Hormones 20. Hormones. What are they and how do they work? Hormones are chemical signals, secreted into bodily fluids  Reach many cells, only targeted cells respond Elicit specific responses in target cells Pineal – melatonin Adrenal – Adrenaline Pancreas – insulin Ovaries – estrogen Hormones are regulators secreted by glands that alter gene function in a target cell somewhere else in the body Testosterone: males score higher in mental rotations, stimulate growth and maintenance of male reproductive system, stimulates secondary sex characteristics, numerous effects on mood and behavior ○ Songbird territories: small birds given testosterone become more aggressive and won territory to increase reproductive success; shorter life span, too aggressive for their size. ○ Rat maze learning: males better only during mating season ○ Chess/ tennis/ football battles: two males competing have elevating testosterone. After competition: winner’s stays high and loser’s decreases. Even fans experience this. Estrogen: females score higher in object memory and math equations (better scores during ovulation); improves memory, concentration, promotes brain cell growth, mating, and fertility, increased levels increases mood Hormones are like radio signals– radio wave is always passing through but you need the radio (receptor) in order to hear it (or for it to react) Example: adrenaline ○ 1. Sense danger – heart rate will increase ○ 2. Glycogen will breakdown in liver and release fatty acids from fat cells ○ 3. Increase rate of heart beat ○ 4. Dilate bronchioles in lungs so more oxygen gets to cells 21. Describe three lines of evidence (each) suggesting that estrogen and testosterone are responsible for some biological male biological female differences? Testosterone ○ 1. Increased testosterone has been linked to enhanced physical performance. This evidence suggests that males are built with higher muscle mass because testosterone stimulates muscle growth ○ 2. Higher testosterone increases mental rotations and spatial awareness. Males tend to do better on these tests than females ○ 3. Testosterone has been linked to increased aggression, which can explain the population within prisons that is disproportionately male.  Estrogen ○ 1. Estrogen has been linked to higher memory, which can explain why females do better on object memory tests than males. ○ 2. Estrogen levels have been linked to mood. When a female enters menopause, her estrogen levels decrease dramatically. This has been linked to depression amongst middle age women, and elevating their estrogen levels to pre-menopause levels helped to alleviate their depression. This could explain the colloquial belief that women tend to have more mood swings then men which varies upon her menstrual cycle. ○ 3. Estrogen is what causes the development of secondary sex organs in females, like breasts and ovaries. Females have larger breasts than males because of their exposure to this hormone. Males exposed to greater levels of estrogen tend to develop bigger breasts, so it is the hormone influencing this gender-related difference. 22. Describe when oxytocin release is stimulated and the consequences. Cortisol too. Skin to skin contact enhances/build trust Oxytocin and cortisol are not related Oxytocin: ○ More trusting of others, can foster relationships, can be bad in that people can manipulate it ○ Depends on where the oxytocin goes that has that receptor (and a lot of other signals at the time) ○ You have something that responds to a que in the environment and it causes a change in your functioning. (that you get some information) ○ Skin to skin contact enhances/build trust In this case it doesn’t change what you do but how your brain works → “oh I have more trust with this person” ○ Financial negotiation game I am going to be more certain that they’re going to take care of you Cortisol: ○ Fight or flight response, long term we deal with it, depresses immune system which gives ulcers ○ Cortisol is released by your adrenal glands when you’re in a situation that you perceive as threatening, stressful, etc. ○ (bc more glucose can be available to your body, so you’re fight or flight response is going to be more affected) Topic Five: Mating and reproduction 23. How does reproductive investment differ between mammals and birds? What are the consequences? Male gametes are smaller than females (so there is asymmetry?) More monogamy among bird species than mammals In both cases (just by definition), the male gamete is smaller than the female gamete → so there is asymmetry in investment Mammals ○ Because of internal gestation and lactation in females, the asymmetry becomes much more significant between males and females energetically. Whereas the fitness pay off is the same Mammals generally invest more heavily in their offspring during gestation and lactation after birth Results → typically having smaller litter sizes with longer developmental periods Bird ○ Birds don’t have internal gestation. There’s an egg. They don’t have lactation. They feed them food. It changes them because they don’t have this constraint where there is always a significant amount of asymmetry. It can be much more equal. And that is a consequence(?) Birds invest most of their reproductive energy into the large, yolky egg they lay, with varying levels of parental care after hatching Results → birds can lay multiple eggs in a clutch with shorter individual development times Q: Why do we see more monogamy among birds than mammals? ○ Eggs (males can sit on the eggs but can’t make them → physical constraint) ○ Defining feature of mammals: lactation (females do this providing huge amounts of lactation for offspring. Mammals lactate, birds can’t → physical constraint) Mating system definitions: ○ Polygyny: [high variance in males reproductive success(RS)]/[low variance in female RS] One male bonds with multiple females Examples: elephant seals, bamboo, (sage grouse?) Most mammals? ○ Polyandry: [low variance in male RS/high variance in female RS] One females bonds with multiple males Example: idk ○ Monogamy: low variance in both, low number of mates each  One female bonds with one male Most birds species (populations) are monogamous 24. Describe the (biological) male (biological) female differences in vulnerabilities when making mating decisions. Do you produce the smaller gamete or the larger gamete? Because the female has made more of an investment early on she’s at risk of being taking advantage of by the male that gets the same evolutionary payoff with less investment Species with great discrepancies ○ We tend to see a greater amount of discrimination against of females than males in terms of whether they will or will not mate But then there is different vulnerabilities ○ Species where there is any maternity uncertainty Even if the offspring really really benefits from both parents providing resources to it to the extent that the male is not sure genetically that the offspring are his, so that when the fitness pay off comes, you get a vulnerability there Bc the female has made more of an investment early on she’s at risk of being taking advantage of by the male Females: more investment (lactation, size of gamete, internal gestation) = more discrimination ○ Demands honest signals of health ○ Peacocks, friggit bird, moose with big rack of antlers ○ Person: height, weight, age Value fighting ability, control of resources, valuable physical attributes ○ Dung beetles, elephant seals Elicit a commitment to invest: ○ Courtship dance: goose follow female for 2 weeks to show he doesn’t spend time with another female ○ Nuptial gifts: builds house for female, she mates with him if she likes it, if not he will rebuild it ○ Bush cricket ejaculates 1/3 of body weight Lower reproductive investment ○ 1. Competition for access ○ 2. Mate guarding/extended mating Male frogs hang onto female so when she lays the egg, he can fertilize it right away Decreases the paternal uncertainty ○ 3. Sperm competition  Have physical differences in build One sex is more vulnerable to the other ○ For example female mammals who agree to mate with male are more vulnerable than males ○ Females in this case are more choosy ○ Males compete to have sex with the female Male make decision after offspring is born if he wants to invest time, energy and food because of paternity uncertainty Females are more vulnerable at point of mating and males are more vulnerable afterwards 25. What is the relationship between sexual dimorphism and mating systems? Why? Sexual dimorphism: DEFINE Sexual dimorphism is a good indicator of mating systems. Larger sex is the competing sex with higher variance in their RS. A lot of male competition ○ Deer have the huge rack of antlers ○ Male Peacocks have the extravagant and colorful feathers Cannot fly around but they risk it Hurts survival Females are able to choose ○ Sometimes it is the dominant male ○ Sometimes it is the one who looks better in the particular trait Greater the sexual dimorphism the stronger the selection – also greater value for the winner Top males get picked the most The more polygamous the more variance in reproductive success Topic Six: Nutrition and macromolecules 26. Are all proteins created equally? Are all fats? Are all carbs? Are all proteins? Describe the difference (and give examples) No each has a category Proteins ○ For construction ○ There are 20 amino acids, we can produce 11 of them ourselves and need to consume the other 9, called essential amino acids Milk, eggs, and meat have all 9  ○ Animal proteins contain all 8 essential amino acids, making complete proteins. Plant proteins do not contain all 8, usually 6, making incomplete proteins, which must be paired with another plant protein to get all 8 essential amino acids. Soy and quinoa are the only plants with complete proteins ○ Only digestible as amino acids or polypeptides ○ Functions as enzymes ○ Can be broken down to release energy or stores as fat ○ Contains a nitrogen which is eliminated as urine ○ Example: hair Curly vs straight hair Sequences of amino acids Color and texture Amino acids binding to other features People inherit either curly or straight hair from their parents Chemicals can break down chains (r group) temporarily the bonds break and you can change the hair Make it straight or curly Water has properties that hydrogen bonds where you can alter your hair and will form new bonds until you get your hair wet again Fats (lipids): ○ Hot water soluble ○ Major storehouse for energy ○ Good insulator ○ Molecule we use for storing and generating useful energy ○ The difference between saturated and unsaturated depends on whether there are double bonds in hydrocarbon tail ○ FOR STRUCTURE – see 10/27 lecture ○ Saturated: more stable, easily stored as fat. Solid at room temperature. ○ More hydrogens. Animal fats, less reactive ○ Unsaturated: less stable, easier to release energy. Liquid at room temperature. Double bonds in hydrocarbon tail, plant/fish oil ○ “Partially hydrogenated” vegetable oils: More like animal fat Stops snacks from being greasy Added hydrogens to oil to make it more solid M&M’s Melt in your mouth, not your hand  Just enough solid ○ Lipids are water insoluble molecules important in energy stored in ○ membranes and as hormones Carbs ○ Glucose – composed of carbon, hydrogen and oxygen o Quick energy ○ All energy used by brain comes from glucose ○ Monosaccharides: simple sugars. Fast energy, readily available Broken down really easily Not packed together as densely as lipids Captain Crunch cereal ○ Polysaccharides/ Starch: Starch Many linked simple sugars. Slow and long release of greater energy Slower Long release Long chains More energy Potatoes Bagels – better study food because it releases sugars slowly and will last longer amount of time (cream of wheat example when Phelan was a grad student) ○ Cellulose All plants Every single cell has a cell wall made up of cellulose ○ 3-7 Carbons ○ CH20 o *Fuel* 27. Describe the chief features of each type of macromolecule. (Show the relationship between the structure and the function. Why they have that dual energy storing building. How their structure allows us to understand why that’s the case) Carbohydrates Fats Proteins Section on macromolecule in textbook is a good place for review Section/chapter in the book on macromolecules You don’t need to write down the chemical structure for tristeron, but I’d like you to maybe be able to sketch it out maybe and just say that it’s got what’s called triglyceride. They have three long  fatty acid tails, and they’re long and can be diagrammed like ____(this)____ because carbon connected to carbon connected to carbon connected to carbon with two hydrogens off the sides, with a ton of energy stored. So the fact that it’s like __(structured the way that it is)___ → it has a huge amount of energy stored at the bottom. (that's how it’s really great for energy storage?) (Sketch out chemical structure for chrsitolom? Fats (lipids): storage of energy long term ○ Mostly about storing energy for longer term ○ If you grow up without food, all of the glucose in your body, glycogen in your muscles, will be gone within a matter of hours. You could live off the fat that is stored in fat cells in your body for weeks and weeks and weeks, probably months ○ Major Types fats/triglycerides The lipids in the diet On food label grams of fat Phospholipids Steroids Regulate development, sex characteristics, behaviors ○ Not water soluble ○ Good insulators Walrus is a warm blooded animal but live in cold water and the thick layer of lipids allow walrus’ to survive in their environment Example: Elephant Seals Same as walrus Example: salad dressing Water and oil do not mix Proteins: construction of cells and tissues (“building blocks”) ○ Used for construction (for building stuff) ○ For building muscles , hair, the lining of your stomach, the enzymes that are going to catalyze the buildup of stuff for your body to break down stuff that you consume ○ Has nitrogen in it Everytime you are building something you need nitrogen and the only place you get it is from protein in your diet BE ABLE TO DRAW THAT ○ Made from chains of amino acids ○ Caused to fold up differently by AA sequence- curly/ straight hair Different folds to create different structures Carbs (carbohydrates):  ○ Mostly about fueling our body ○ Molecules connected to OH’s ○ Burst of energy as break down molecules easily (Won’t ask for the structure of carbs or fats) 28. Why do taste preferences exist? They reduce the amount of time you have to spend getting food allowing you to maximize your fitness Evolution has shaped our taste preferences, making us love energetically rich fats Hunter gatherers looking for energy, we have inherited this preference because those preferred fats have more calories and were more likely to survive and reproduce Fats have more calories per gram than carbs or proteins Fats have twice as much energy 29. What is dietary fiber? Why is it valuable? Fiber = indigestible carbohydrates that can’t get digested so they go through the system and scrape and clean the bowels Cannot break it down – you don’t get any energy from it All plant material has cellulose (fiber) Fiber: plant structures, which cannot be digested by humans ○ Cellulose, pectins, gums, lignins Valuable because it aids in digestion: ○ Helps move food through you gut ○ May lower cholesterol by preventing absorption of it ○ May reduce colon cancer risk; scrapes and pushes along to assist in excretion ○ Improves heart health o Reduces cholesterol Think of fiber like a steel wool brillo pad moving through the digestive system – chyme is able to latch on and pulls the chyme through as well 30. What are vitamins and minerals? 5 categories/situations where you need them Vitamins: ○ Necessary organic molecules ○ Organic molecules are needed as raw materials when the body creates enzymes. ○ Fat-soluble vitamins pass into fat cells and stay there, accumulate, and can have adverse reactions. ○ Water-soluble vitamins are excreted through the urine and are not stored. Minerals:  ○ Necessary inorganic elements In the U.S. almost no adults suffer from vitamin/ mineral deficiency disease- so most people gain no benefit from supplemented vitamins. Taking fat soluble vitamins when you do not need them can have adverse reactions ○ Too much vitamin A= hair loss in men ○ Too much vitamin D= growth retardation ○ Liver damage from excess vitamins and minerals Some people need vitamins: ○ Pregnant and breastfeeding women ○ People on extreme caloric restriction ○ People with low milk consumption and extremely low sun exposure may need extra vitamin D ○ People with absorption problems (such as when on antibiotics) o Women who lose unusually large amounts of blood during menstruation may need extra iron 31. Describe the general process of digestion and absorption. 1. Mouth → 2 functions ○ Mash up food ○ Partially digest starch If you chew a bite of a bagel and let it sit on your tongue for 20 minutes it will break down and you will be able to taste sugars ○ This is important because you have to increase the surface area of the food because the stomach cannot break down the outside layer of foods – need to gain access to the nutrients inside 2. Stomach → 3 functions ○ More food mashing ○ Short protein digestion ○ Secrete acid: denature protein, kill bacteria 3. Small intestine → 4 features ○ 20 feet long ○ Neutralize chyme pH Return to a pH of 7 ○ Finish protein/starch digestion ○ Digest lipids (bile) Lipid – don’t dissolve in water Bile is stored in gallbladder Bile breaks down greasy aggregations so enzymes can get access to them  ○ Absorb nutrients and a little bit of water To do this you need a lot of surface area Some people who are trying to lose weight have a surgery done where part of the small intestine is removed so less is absorbed in the small intestine ○ Most nutrients are absorbed here 4. Large intestine → 3 functions ○ Mostly water is absorbed here ○ Absorb nutrients produced by bacteria ○ Push chyme into rectum for exit Digestion: Take food in in order to get access to macromolecules by breaking then down in different parts of the body Absorption: getting nutrients into the bloodstream and getting it to where it needs to be. Small intestine, large intestine 32. What is BMR? Why is it useful? How does it differ from metabolic rate? Basal Metabolic Rate (MR): ○ BMR is the minimum amount of energy your body needs to perform basic functions like breathing, blood circulation, and cell repair while completely at rest; essentially, the calories your body burns just to stay alive Usefulness: ○ Essentially, the calories your body burns just to stay alive, making it a useful tool to understand how many calories you need to maintain your current weight or adjust your diet for weight loss or gain ○ It is useful because it represents the minimum amount of calories your body needs to perform basic functions like breathing and cell maintenance, essentially giving you a baseline understanding of how many calories you should consume to maintain your current weight, and allowing you to adjust your diet accordingly to either lose or gain weight based on your goals Difference: ○ BMR (Basal Metabolic Rate): refers specifically to the minimum amount of energy your body needs to perform basic functions like breathing and organ function while completely at rest Measurement: usually measured under very controlled conditions, like after a fast and with no recent physical activity Application: often used as a baseline for calculating calorie needs  ○ Metabolic rate: encompasses the total energy your body uses for all activities, including physical movement, digestion, and basic bodily functions, meaning it is always higher than BMR when you are not completely at rest. Measurement: can be measured under various activity levels Application: is more useful for understanding overall energy expenditure throughout the day Topic Seven: DNA fingerprinting 33. What are STR loci and how do they differ from each other and other STR lowsigh beings? Use these in a description in how DNA fingerprinting works (be able to describe them) High variable. IMPORTANT THING is that they are highly variable. Inherited just like structural traits (in billions. Mendel’s law of segregation). But they don’t code for anything 34. The science behind DNA fingerprinting is universally accepted. Why are there still reasonable criticisms about its use? The existence of STI loci High amount of variation The way they are inherited The fact that we have a lot of them in our genomes so we can look at 10 or 12 or 13 of them Using PCR to separate out the fragments to figure out what someone did ○ All of the above are true Take home message about DNA fingerprinting ○ It is about the best thing to come to criminal justice ever. Both for catching criminals and releasing people who were accused of something but did not commit the crime Reasonable criticisms about its use ○ There’s a long historical record of people, shooting(?) somehow, contaminating sources, labs that don’t have high levels of quality control ○ Cities or counties that don’t have oversight properly to make sure that they are doing the labs right If those are true then you want to be cautious. You want to have blind testing done that are assuring us that it is being used the way it is suppose to Potential Pre-Midterm Topics (my guess): What is revealed preference? Why is it important? Revealed preference: preference shown through behavior, not based on what a person says A way of evaluating which reminds us that perceptions of thought can be different from actual behavior Also known as RP Example: when someone says they like movies and then you ask them what is the last movie they have seen and it was a movie from several years ago the revealed preference speaks louder than their words What is the naturalistic fallacy? What is an example of how people commit it? The assumption that things that are natural are good and things that are unnatural are bad Just because something is produced by natural selection doesn’t mean that it is morally good/right. Just because something is unnatural doesn’t make it morally bad Example: ○ Food labels advertising “all natural” ingredients. This does not mean that it is healthier for you, however many people believe that when they see those words People commit naturalistic fallacy unconsciously People making the mistake that there is a linkage between natural and good and unnatural and bad Scientific thinking: Why is it so useful? How can we apply it to nearly every aspect of our lives? (Be able to use it) Scientific thinking has the ability to illuminate situations in which we should change what we think. There are 5 different steps that we follow. ○ 1. Make observations ○ 2. Formulate hypothesis ○ 3. Make predictions ○ 4. Collect observations in a collective way (test hypothesis and alternatives) ○ 5. Draw conclusions, and modify our hypothesis if necessary An efficient way to learn about and understand the world Observations, hypothesis, prediction (if...then), critical experiment, conclusions Critical experiment ○ Control → control group, testing for one thing ○ Randomization → people being tested are random ○ Double blind → neither receiver or provider know what treatment is being given  Female named hurricane, hurricanes kill more people. Don’t take them as seriously when named after females (possibility) Evolution and Natural selection: What are they and how do they work? Evolution: ○ A change in allele frequencies within a population ○ 4 mechanisms/agents (that allow it to occur) 1. Mutation: an alteration of the base-pair sequence in the DNA of an individual's gamete-producing cells that changes an allele’s frequencies 2. Gene flow (migration): WITHIN a population some individuals leave or new individuals arrive, thus changing the overall allele frequencies 3. Genetic drift: a random change in allele frequencies caused by individuals moving into or out of a population 4. Natural selection Three conditions: variation, heritable, differential reproductive success Natural selection: ○ Must have three conditions in order to occur: Variation/variance Example: eye color Heritable/heritability Example: offspring resemble their parents Differential reproductive success turkeys with large breast reproduce more than turned with smaller breasts ○ Types of natural selection Directional selection Individuals with 1 extreme of the variation range have higher fitness Mean changes, variation decreases Example: farmers selectively breed cows with high milk production so subsequent generations will have less low milk producing cows Stabilizing selection When individuals with intermediate phenotypes have the highest fitness  Mean stays the same, variation decreases Example: birth weight Disruptive selection Individuals with extreme phenotypes have the highest fitness Bimodal distribution, variation increases Example: big fish can defend territory and small fish can sneak in and fertilize the eggs but the intermediate sized fish can't Artificial selection Goal oriented selection of favorable traits to produce offspring with more and more exaggerated versions of these traits Differential reproductive success is determined by humans Example: animal breeders breed dogs for specific traits for shows Genetics! Why do kids look like their parents? Why aren’t they (siblings) identical to each other? Mendel's first law → mendel’s law of segregation ○ → A gamete receives only 1 allele from each gene (even though the organisms generally has 2) ○ → Fertilization reestablishes the diploid number ○ The law of segregation points out that a gamete receives only one allele from the pair of alleles possessed by an organism ○ As a result of mendel's law of segregation Half sperm carry an y-chromosome Half sperm carry an x-chromosome All eggs carry an x-chromosome Love and Kindness! Why are we nicer to our relatives than others? Hamilton’s rule helps us predict when we’ll see kindness among genetic relatives B*r>C ○ (Natural selection is favoring whatever allele we are talking to (when true)) ○ B = benefit to relative ○ r = coefficient of relatedness (goes from 0.0-1.0) ○ c = cost to me ○ For situations in which this equation is true, we expect the “kind” act to occur ○ Hamilton’s rule → (says) when and why individuals should exhibit apparent altruism (acts of kindness) towards genetic relatives Hamilton’s rule But coefficients were of relatedness. The most important part is to know exactly what you said. As that gets higher, the likelihood that b times r is greater than c goes up. We're more likely to see acts of apparent altruism. As r goes down, it's less likely that b times r is greater than c, and it's less likely that we see those acts of apparent altruism ○ Apparent altruism: is any action that looks like it comes at a cost to the individual doing it while benefiting some other individual (definition from class review session) Love and Friendship! Why is “friendship” rare among animals? Why is it so common among humans? Why does unconditional love not exist? Why is friendship rare amongst animals? ○ Cooperation amongst non-kin is almost non-existence in the animal worlds (out of ∼2 million species) → Cooperation is rare in the animal world ○ Sad reminder: among unrelated individuals, selfishness is the rule. Kindees is the exception ○ Vampire bats One of the only cases of apparent altruism among unrelated individuals Suck blood for food 10% of adults and 33% of juveniles fail to find a meal on any given night A bat will starve to death on more than two nights in a row A “full” bat with sometimes regurgitate blood meal into a hungry bat’s mouth A bat is significantly more likely to give food to bats that have previously helped it Bats shun individuals that do not help them ○ “Most animal interactions are primarily driven by survival needs like food, reproduction, or protection, meaning their relationships tend to be more transactional and less based on emotional connection like human friendships”  Why is it so common among humans? ○ “Humans, on the other hand, have a complex social structure that necessitates cooperation and emotional bonds, making friendship a key evolutionary advantage, allowing for greater social support and cooperation” ○ Example: (rule of thumbs) I look at some other individual and I don't know if that other individual is my genetic relative. But he has the same last name as me and we shared a room from the time we were little kids. We shared a room in the dorms, he calls me all the time, he looks and sounds like me. Those are all rules of thumb that tell me he's probably a relative. Therefore, you should behave in ways that benefit him because they're gonna help you out So I don't know that it's true, but if I follow these rules of thumb, they tend to get the outcome that is good Why does unconditional love not exist? ○ Come back to if I have time Love and Kindness! How can you enhance your friendships? “Your avenues to enhancing cooperation” ○ Tinker with the perceived costs and benefits 1. Reduce the perceived cost to the person 2. Accentuate the benefit that you’ll receive from the cooperation (Our levels of kindness/selfishness is influenced by the cost of kindness) ○ (being able to) distinguish cheaters and kind people 3. Facilitate the building of reputations 4. “honest signals” that can’t be faked 5. Keep track of and punish cheaters (Our level of kindness/selfishness is influenced by how we perceive the benefit to the recipient) (our motivation to do acts of kindness is influenced by “reputation enhancement” ○ Reduce the perceived vulnerability of partners 6. Make the first step: gifts 7. Acknowledge debts clearly and concretely (our motivation to do acts of kindness is influenced by “reputation enhancement”) Why is it so easy to remember gossip? (even about people you will never meet) Q: what brain features would be useful for a species during reciprocal altruism? We out to excel at remembering faces  ○ Vampire bats: hundreds Humans: thousands ○ We ought to be good at keeping track of cheaters ○ We out to be voracious consumers of social information Who is this? What do you know about him? Gossip, social info, and protection from cheaters *Why are our brains good at keeping track of social information? *Why do we keep tabs on people we’ll never see? ○ Our brains were built for a world in which we encountered only a small number of people (∼100) and we may have needed any one of them ○ (Take home message) humans recognize faces, keep track of kindness and sleepiness, and live for a long time. This makes reciprocal altruism possible But we’re extremely aware of our vulnerability (and act accordingly) “Gossip is easily remembered because it often triggers our brain's reward system, making it engaging and stimulating, especially when it involves negative or juicy information about others; this is linked to our innate social nature, where understanding social dynamics and reputations within a group is important for navigating social situations, even if the people involved are strangers” Etc (if time allows) PEDIGREES Coefficient of relatedness MC questions we came up with!