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The Exam Has 200 Points 1. EVOLUTIONARY PSYCHOLOGY

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The Exam Has 200 Points 1. EVOLUTIONARY PSYCHOLOGY Bio 312, Fall 2018 Exam 4 ( 1 ) Name:__________________ Please write the first letter of your last name in the box; 5 points will be deducted if your name is hard to read or the box does not contain the correct letter. The exam has 200 points 1. EVOLUTIONARY PSYCHOLOGY. Empathy is often considered a uniquely human trait, but does helpful behavior based on empathy exist in other organisms? In 2015, Sato et al (Animal Cognition 18:1039-1047) studied whether rats would assist other rats who appeared to be in distress. Cages were set up in which a focal rat would be in the middle "ground" area while another rat was placed into water in a "pool" area and had to swim for up to 5 minutes (which they do not like at all). In experiment #1 the researchers then measured the time taken (latency) for the focal rat to open the door to the pool area and allow the "soaked rat" to escape. They gave each rat 12 sessions of 300 seconds and measured how long it took them to open the door. Since this behavior may just reflect helpfulness and not empathy, they reversed roles and then did the same test with the "soaked rats" from the first trials - the reasoning being that if they demonstrated the helpful behavior more quickly after experiencing the soaking, then this may be due to increased empathy. (a, 3 pts ea) In the pair of figures below draw data that does (left) and does not (right) support the hypothesis that rats feel empathy for other rats in distress and that this is enhanced when they have experienced the same distress themselves. Use dark and open circles to represent the mean values for the two treatments in order (i.e., initial naive rats in dark and role-reversed rats with open circles). 300 250 Actual figure 200 opening (sec) opening from paper - 150 100 50 0 Latency to to door Latency 1 2 3 4 5 6 7 8 9 10 11 12 These results are not enough because this helpful behavior may also arise just from a pro-social behavior in which the rats just want companionship, regardless of what's happening to the other rat. The experiment was therefore repeated, Experiment #2, but there was no water in the pool area. (b, 3 pts ea) In the pair of figures below draw data that does (left) and does not (right) support the hypothesis that the helpful behavior was driven by empathy for other rats in distress instead of just a desire for companionship. Use dark circles to represent the mean values for the treatment. 300 250 200 opening (sec) opening Actual figure - 150 from paper 100 50 0 Latency to to door Latency 1 2 3 4 5 6 7 8 9 10 11 12 Bio 312, Fall 2018 Exam 4 ( 2 ) Name:__________________ 2. HUMAN EVOLUTION. I claimed that evidence exists that implies that Homo neanderthalensis individuals were some of the first humans to truly consider the wellbeing and metal state of their fellows as well as have thoughts about abstract ideas about situations they could not see or hadn't experienced. These are key steps in the achievement of true conscious being. List the two pieces of evidence and what they each may imply. (4 pts each) Piece of evidence 1: A fossil with a healed broken leg indicates care taking of those too injured to care for themselves. Piece of evidence 2: Flower petals placed on the bodies of the dead suggest that perhaps survivors had concepts of an afterlife they were improving or that the dead body had meaning beyond just a corpse. When looking at the fossil skulls of our relatives and ancestors, I described three general trends in the evolution of the human skull over time. Two of these trends are apparent from a lateral view of the skull while the other is best observed from underneath. These trends indicate changes in lifestyle and behavior of our ancestors. Describe the changes in the skull due to each of the following inferred changes in the lifestyle or other traits of our ancestor. (4 pts each) (a, trend associated with intelligence): The size of the brain increases in animals with larger groups sizes as the brain is selected to process more social relationships, the human brain increased as our groups increased in size and the complexity of our behaviors increased. (b, trend associated with food): The size of the jaws reduces and the mouth protrudes less as we shifted to eating softer foods and cooked foods, causing a flatter profile face. (c, trend associated with upright posture): The foramen magnum moves anteriorly on the ventral surface of the skull as the spine moves under the skull due to a more erect upright walking posture. Bio 312, Fall 2018 Exam 4 ( 3 ) Name:__________________ 3. HETEROZYGOTE DISADVANTAGE. Consider Genotype Fitness a scenario of asymmetric underdominance with fitness values AA 1 represented as in the box to the right. Aa 1-s aa 1+t (a, 4 pts) Derive the equation for 푝̂, the equilibrium frequency of the "A" allele. (Show all steps in your derivation) 푝푞 ∆푝 = 0 = [푝(푤 − 푤 ) + 푞(푤 − 푤 )] 푤̅ 11 12 12 22 0 = [푝(1 − (1 − 푠)) + 푞(1 − 푠 − (1 + 푡))] 0 = [푠푝 − 푞(푠 + 푡)] 0 = [푠푝 − (1 − 푝)(푠 + 푡)] 0 = 푠푝 − 푠 − 푡 + 푝푠 + 푝푡 푠 + 푡 = 2푠푝 + 푝푡 푠 + 푡 = 푝(2푠 + 푡) 푠 + 푡 푝̂ = 2푠 + 푡 (b, 2 pts) If s=0.1 and t=0.2, what would the equilibrium frequency of the "A" allele be?. (You must show your work) 푠 + 푡 0.1 + 0.2 0.3 푝̂ = = = = 0.750 2푠 + 푡 0.2 + 0.2 0.4 (c, 4 pts) If p=0.7 and using the values for s and t from part (b), what is ∆푝, the change in the value of p in a single generation? (Show all steps in your calculation) 푝푞 ∆푝 = [푝(푤 − 푤 ) + 푞(푤 − 푤 )] 푤̅ 11 12 12 22 (0.7)(0.3) ∆푝 = [0.7(0.1) + 0.3(−0.3)] 푤̅ 2 2 substitute, 푤̅ = 푝 (푤11) + 2푝푞(푤12) + 푞 (푤22) = (0.49)(1) + 0.42(0.9) + 0.09(1.2) = 0.976 0.21 ∆푝 = [0.07 − 0.09] 0.976 ∆푝 = 0.215164[−0.02] = −0.0043 (d, 2 pts) What does your answer in (c) imply for the stability of the equilibrium you calculated in part (b) and why? Since ∆푝 is negative when the frequency is smaller than the equilibrium, the equilibrium is unstable because a negative perturbation will result in the fixation of the "a" allele. Bio 312, Fall 2018 Exam 4 ( 4 ) Name:__________________ 4. PHYLOGENETICS. Consider a set of eight taxa - A, B, C, D, E, F, G, H - for which the phylogeny can be described using the following: - Taxa A, B, D, and G constitute a monophyletic group. - Taxa A, B, and G constitute a paraphyletic group. - Taxa C, F, and H constitute a monophyletic group. - Taxon E is the outgroup. - There are only two sets of sister taxa: B and G, F and H. In the two boxes below draw the correct phylogeny for these eight taxa. In the box on the left use orthogonal lines with more recent events further to the right. (4 pts) In the box on the right use angled lines with more recent events closer to the top. (4 pts) (A miniature diagram of the desired format is shown in each box) E E C H F A D G B C H F A D G B 5. BREEDER'S EQUATION. Consider a situation in which a population of 284 individuals has a range of values for a quantitative trait like mass. (a, 5 pts) Consider a scenario in which the mean of the overall h2 = 0.300 population is 280 Kg and a subset with a mean mass of 290 Kg is chosen for mating, if they produce an offspring generation with a mean mass of 283 Kg, what is the narrow sense heritability of the population? (provide answer to nearest 0.001) (b, 5 pts) Now consider a scenario in which we choose a subset Mean = 283.900 on individuals with a mean mass of 286 Kg from the offspring generation and mate them, what is the expected mean mass of the third generation? (provide answer to nearest 0.001) Bio 312, Fall 2018 Exam 4 ( 5 ) Name:__________________ 6. PHYLOGENETIC RELATIONSHIPS. Use the list of taxon scientific names below to fill in the blanks (one has been filled in for you for reference) for the phylogenetic tree shown. (8 pts) Annelida Homo Pongo Arthropoda Mollusca Porifera Dipnoi Nematoda Platyhelminthes Echinodermata Onychophora Sirenia Gorilla Pan Tyrannosaurus porifera platyhelminthes mollusca annelida arthropoda onychophora nematoda echinodermata Dipnoi Tyrannosaurus Sirenia Pongo Pan Homo Gorilla Also, answer these questions (2 pts ea): ► Note that in the phylogeny above, the protostomia taxa are split into two groups. Each of these two groups has a technical name, they are the ___Ecdysozoa___ and the __Lophotrochozoa__ ► Note that the bottom eight taxa all belong to the same monophyletic group, this group is called the ___Dueterostomia______ ► Note that the bottom five taxa all belong to the same monophyletic group, this group is called the ___mammalia______ Bio 312, Fall 2018 Exam 4 ( 6 ) Name:__________________ 7. POPULATION GENETICS (a, 3 pts) If a recessive lethal disease is observed to afflict 1 in freq. = _0.002236_ every 200,000 babies what is the frequency of this allele? from q2 = 1/200,000 (b, 3 pts) If a dominant deleterious disease has a fitness cost of 10% freq.
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