BIO A 208 Exam 1 Questions And Answers With Verified Solutions

What are the three criteria of a good scientific explanation? - Falsifiable predictions, replicability, parsimony Define proximate explanations - During the organism's life -- anatomical/physiological -- "how" Define ultimate explanations - evolutionary -- functional/historical -- "why" What are the ways one can test ultimate explanations? - Correlation and Experimental Manipulation Where is the nature and nurture dichotomy useful? - In dealing with MEASURABLE components (ex: heigh, weight) What is the blank slate view? - That the human mind is "a general purpose learning machine, capable of acquiring whatever information to which it was exposed" Define Heritability - the proportion of total phenotypic variability observed for a given trait that can be ascribed to genetic factors Why is heritability important? - It shows how different just one trait can be within individuals based on genetics. What is evolution - A change in the genetic structure of a population. The term is also frequently used to refer to the appearance of a new species. What are the four forces of evolution? - Mutation, Genetic Drift, Migration, Natural Selection Define mutation - The ultimate source of all genetic variationDefine migration - Individuals of any species moving around and sharing genes among populations. Define genetic drift - Random population change overtime;bottleneck; founder effect Define Natural Selection - Non-random population change overtime. What are the prerequisites for evolution by natural selection? - Variation, differential reproduction, heritability What are the factors that govern the rate of evolution by natural selection? - Strength of association between variation and reproductive differences, Heritability, Generation time How does heritability affect the rate of evolution? - The higher the heritability, the faster the rate. What are the three constraints on perfection. - Cost, Variation (chooses only from available choices), Time (organisms adapt to ancestral environments) Define obligate adaptions - Traits that are not affected by the environment Define facultative adaptions - Trait changes in relation to environmental variable Facultative adaptions have _______ heritability - low what is mental modularity? - The thought that the mind is a collection of facultative adaptions. What are the three levels of selection? - gene, individual, groupWhat is the problem with group selection? - It favors traits that benefit the group rather than the individual What are a gene's two routes into the next generation? - Front Door; Back Door Front Door: - Good genes pass on because it will increase the fitness of it's carrier or will inevitably spread. Back Door: - Genes that decrease fitness of it's carriers in order to increase the reproduction of other bearers. What is kin selection? - a gene can spread by increasing the reproductive success of other bearers of the gene at a cost on one's own reproductive success. What is Hamilton's rule? - rb>c What is inclusive fitness? - the sum of one's own reproductive success and one's effects on the reproductive success of kin What is sex? - The recombination of DNA from two individuals to produce an organism with a novel genotype. What are the costs of sex? - Recombination (untested genotypes), meiosis (only passing 1/2 of genes), producing sons, mating (time, energy, vulnerability, disease risk) What are the four hypotheses put forward concerning evolution of sex? - Adaptability hypothesis, Muller's ratchet, Lottery principle, Red Queen Hypothesis Describe the Adaptability hypothesis: - a hypothesis concerning the evolution of sex: variability is generated.Describe Muller's Ratchet: - a hypothesis concerning the evolution of sex: mutations don't affect all offspring in sexual populations like they do in asexual populations. Lottery principle applies to ____-selected species; benefits the ____________ - r ; parents Red queen hypothesis applies to ___-selected species; benefits the ________ - k ; offspring Define anisogamy - sexual reproduction by the fusion of dissimilar gametes. The 4 mechanisms of sexual selection: - Contest competition, mate choice, sexual coercion, sperm competition Describe Contest Competition: - Intra-sexual selection: Traits favored (size, strength, aggression, weapons, threat displays) Describe Mate Choice: - Inter-sexual selection: Traits favored (behavioral and morphological traits that attract mates) Describe Sexual Coercion: - Inter-sexual selection: Traits favored (harassment, punishment, forced copulation) Describe Sperm Competition: - Intra-sexual selection: Traits favored (favors the males with large ejaculates) Why did sexual dimorphism evolve? - What is Batemen's principle and how does it relate to reproductive variance? - Greater variance in reproductive success in one sex relative to the other results in increased opportunity for sexual selection. Characteristics of the fast sex: - more eager to mate, less choosy.Characteristics of the slow sex: - choosier, provides greater parental investment. What is the Coolidge Effect? - The ability to copulate with a new partner right after copulating with one Four costs of choosiness: - Time, energy, predation risk, opportunity costs. What are the non-genetic benefits of choosiness? - Investment and resources Fisherian Runaway Sexual Selection - a trait that initially has natural selection value eventually drives trait to extremes and produces "sexy sons" Hamilton-Zuk hypothesis on Sexual Selection: - Mate choice based on traits that indicate heritable disease resistance. Lek Paradox (How genetic variability is maintained in populations): - Females prefer good genes => shifts population toward favored genes => lower heritability (because everyone has it), variation maintained. Operational Sex Ratio: Arrows - Parental investment -> relative reproductive rates -> operational sex ratio -> opportunity for sexual selection