BZ 300 1st Edition Lecture 19Outline of Last Lecture I. Mate Choice continued…a. Mate Choice can be based on:i. Possessions of Potential Mateii. Indicator of Genetic Qualityiii. Nuptial Gifb. Female Mate Choicei. Good Genesii. Resourcesiii. “Sexy Son” Hypothesisc. Intersexual Selectioni. Fisher’s Runaway Selection Hypothesisii. Zahavi’s Handicap Hypothesisiii. Secondary Sexual Traitsd. Intrasexual Selectioni. Scramble Competitionii. Mate Guardingiii. Female Social Groupsiv. Cooperative Malesv. Leksa. Afer Matingvi. Sperm Competition1. Spawningvii. First Male Adaptionsviii. Secondary Male Adaptationsb. What If you Lose?ix. Alternative Strategies1. Conditional Strategies2. Behavior PolymorphismII. Mating Systemsa. Polygynyi. Resource-Defense Polygynyii. Female- Defense Polygynyiii. Male-Dominance Polygynyiv. Scramble Polygynyb. Monogamy c. Polyandryd. PolygynandryThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Outline of Current LectureI. Mating Systems continued…a. Polygynyi. Male Dominancy Polygyny1. Lek2. Example: Male Sage Grouse3. Why a Lek?b. Monogamyi. Why?ii. Malesiii. Femalesc. Polyandryi. Classicalii. Cooperatived. Polygynandry and Promiscuityi. Advantages of Polygynandryii. PromiscuityII. Hormones and Sexual BehaviorIII. Good Genes Modela. Other Genetic Considerations for Mate Selectioni. Assess Inbreeding/Outbreedingii. Major Histocompatability Complex Lociiii. Fluctuating Asymmetryiv. PlumageIV. Nesting, Parenting and Territorialitya. Teaching vs. Observational Learningi. Nesting1. Examplesb. Parental Investmenti. Can Take Many Formsii. Life History Traits1. R-selected2. K-selectedCurrent Lecture:I. Mating Systems continued…a. Polygynyi. Male Dominance Polygyny1. No monopolizable resources2. Lek- an area where males congregate and defend small territories in order to attract and court females. The territories are of no use or attraction to females. Spatially clustered territories that contain no resources3. Example: Male sage grouse are twice as big as females and a lot more colorful. 100 males in a lek creating loud high-pitched sounds, females come and choose a male. Not sure as to how the females choose the sage grouse.4. Why a lek?a. Reduce predationb. Increased signal/range timec. Special habitats may be required for that lek to show off specific signals are features.d. Or an area where females gather and show up. Females may prefer leks, because it reduces predators, put all of the best males in one are area, and facilitates mate choice in the hands of the female.b. Monogamyi. Why? Under what circumstances does it evolve?1. Males- evolves when circumstances must prevent them from being polygymous. Monogamy benefits offspring survival.2. Females- would evolve if no advantage of re-mating and polygymy is really high and it is never better to be second female. 3. Help is essential for offspring4. Polygymy threshold never reached5. Dominant female may not allow 2nd female6. Males defend single females7. Cost of acquiring mates- entire reproductive costs require the female to make the right choice in one mate, because you only get one change8. Methods to get around the cost of monogamy, and help if the female makes a poor choice- bet hedging: a. Serial Monogamy- monogamous for only one mating season, then find a new mateb. Extra pair copulations- helps to enforce monogamy. c. Polyandryi. Classical1. Male sets up breeding sites and females come and divide attention among all the males. Females have a better chance than the males do ofmating multiple times. Males incubate and rear young, while females get many mates.2. Example: spotted sandpiperii. Cooperative1. Group of males share effort with one female2. Example; Tasmanian Hen- ofentimes related males will help female to raise young. This can occur in harsh conditions or with limited resourcesd. Polygynandry and Promiscuity- Everyone is mating with everyone. We see this when males mate with multiple females and its advantageous for females to mate with multiple males.i. Advantages of Polygynandry1. Nuptial Gifs2. Care of multiple mates- if no one knows who the offspring is, than many can care for the young3. Reduce Cost of harassment4. Reduce disruptive influence of competition5. Hedge against first mate infertility6. Obtain enough sperm7. Can be fertilized by more than one male, which will increase genetic diversity8. Promote sperm competition, higher fitness of offspringii. Promiscuity- males and females appear to mate random. No pair bonds, this is probably very rare. 1. True promiscuity could only evolve when there is no basis for choice: toounpredictable, no territoriality. II. Hormones and Sexual Behaviora. *Note: Error p 328- LH/FSH from pituitaryb. LH linked to female receptivityc. Gonads respond to LH and FSh by producing steroid hormonesd. Afer ovulation LH/ estrogen fallse. Progesterone increases if pregnantf. Vasopressin and Oxytocin-from pituitary-for pairbonding, etc. g. Both sexes have testosterone and estrogeni. Different concentrations based upon sex, depending on whether a male or female.h. Testosterone is linked to aggression/territoriality i. Castration improves domestic behavior in animalsIII. Good Genes Modela. Costly signals can be an honest indication of mate quality. It is very hard for a weak male to be able to fake the signal. This can and ofen is linked to good functioning sets of genes.b. Good genes go beyond simply assessing the mate and the Good Genes Model. Two pieces to fitness: staying alive yourself and your genes getting passed down. A lot of animals need to be able to judge whom to share this immense invest with. Other geneticconsiderations for mate selection:i. Assess inbreeding/outbreeding: 1. Inbreeding likelihood that both copies of the allele will be the same, very little genetic variation2. Ways to avoid inbreeding:a. Sex Biased dispersal: one sex stays and the other sex disperses elsewhereb. Animals learn the identities of littermates and will not mate withthemc. Genetic Cues that reveal kin, can be expressed through odor. If kin share genes than you should be able to recognize the expression of the genes. ii. Major Histocompatibility Complex Loci- (MHC)- variability beneficial. *Note: Look up in book! Very Confusing.iii. Fluctuating Asymmetry (FA)- animals tend to prefer other animals that are moresymmetrical than less symmetrical. Symmetry may