Anthropology 569

Sex Differences & Sexual Selection in Primates

Spring, 2008

Drawing by Nicholas Hall after Niko Tinbergen  Photo by Hermann Eisenbeiss/Frank W. Lane

From: Halliday, T. 1980. Sexual Strategy. University of Chicago Press, Chicago.

Instructor: Ryne A. Palombit

Prerequisites:  Permission of instructor (substantial background in behavioral ecology and/or primate behavioral biology)


Goal of Seminar:

Our goal is to reach some conclusions about the current state of studies of sex differences and sexual selection in the order Primates.

As a focal point of our efforts, we’ll consider the following interesting situation.  Primatologists spend a lot time talking about sex differences, male-male competition, and female choice in primates.  And yet, studies of nonhuman primates typically do not figure very prominently in general reviews of sexual selection (consider Anderssons’ tome, for instance).  Why is this?  Is it because the studies haven’t yet been done in primates?  Is it because the studies have been done, but they haven’t been done very well?  Is it because the studies have been done, and they’ve been done well, but there is currently little evidence for the action of sexual selection in primates?  Or, finally, have well-executed studies generating evidence for sexual selection failed to attract the attention they’re due?

We will address these questions for some major areas of sexual selection theory.  Even though it is now 13 years old, we’ll use Andersson’s book as our major reference work for what is considered “state of the art” sexual selection research (it remains the best comprehensive review of data, even if not completely up-to-date).  Using Andersson as a model, we’ll then evaluate what’s been done and not done (and what needs to be done), what’s known and not known (and needs to be known) in primate studies.   In other words, if Andersson were to update his work, do you think primates would figure more prominently in the new edition, just the same, or less?

Bring to my attention new papers or topics you run across that you think might merit our consideration.  The syllabus is flexible and we will alter it to suit current trends, findings, or interests.


Once or twice during the semester you’ll moderate discussion.  This means leading the discussion by offering your critical evaluations of the readings.  This does not mean simply rephrasing the content of the papers.  Rather, take a position on the work and present it.  Foster debate by presenting opposing views on a subject.

One of your responsibilities as moderator is to do a (computer) search of the literature on the topic you’re moderating and make recommendations regarding papers we should read in class.  The question basically is: are there other papers of enough importance to recommend we drop the currently assigned reading (see below) and replace it?  Your recommendations don’t have to be necessarily based on in-depth analysis of each paper.  Rather, you should be able to make a preliminary evaluation based on a quick reading of it.

    So, two weeks before your moderating date, you should hand in to me (or email to me) a list of several papers  (no more than 5) you’ve run across that you think are relevant for the discussion.  Then, for each one, explain in a few sentences why you recommend it or don’t recommend it for as a reading for the seminar.


Each meeting will have one person who will act as rapporteur, charged with summarizing the important points of the discussion that day.  This should generally be only one page (single-spaced).  Rapporteurs should link ideas with the people who offered them, and should identify and highlight in their reports the following:  (1) the 3 most important ideas presented (and explain why); (2) the best quote of the day (linked to the person who generated it).  Email the summary to me within 24 hrs of the meeting.  After checking it, I’ll then put in on the Sakai site.

Position Papers:

A couple times during the semester you will write a “position paper.”  These are brief and cogent articulations of your position and the support for it.  Position papers on a topic will be photocopied and distributed to everyone.  We will read the papers and then discuss them in the next meeting.  You are not graded on the position you take.  What is required for full credit is a serious effort to state a convincing position.
    The first position paper is a professional review of Zuk’s popular book.  Write as a biological anthropologist for an intended audience of biologists.  You will want to address: (1) whether or not it does justice to the subject; and (2) how empirically and theoretically sound the book and its ideas are.  To do this you will call upon your knowledge and understanding of the subject material derived from readings in and out of seminar.  Identify the way Zuk approaches and defines questions, and how she handles theory and data to answer them.  (Examples of book reviews can be found in the pages of just about any journal, but those in Science and Nature are useful).  Your review should be less than 2000 words (that’s about 3.5 pages single-spaced).
    The second position paper will come toward the end of the seminar.  This paper is somewhat similar to the “Open Peer Commentary” exemplified by journals such as The Behavioral and Brain Sciences. Position paper 2 should not exceed 1500 words.  Due date and topic TBA later in semester.  Remember: take a position and convince the reader of it.
    EMAIL:  On the due dates, please email your position paper to me at  Please do not email participants in the course directly. Around 5pm on the due date, I will email all position papers to everyone.  Make sure yours reaches me before then!


You will choose some topic in sexual selection.  There are many possible topics: female choice, male choice, benefits of mate choice, male-male competition, female-female competition, visual signals, speciation, acoustic signals, alternative mating tactics, body size dimorphism, weapons, cognition,  just to name a few.   You will pick some phenomenon in sexual selection & present the hypotheses explaining it (or variation in it).  Then review empirical evidence for the hypotheses and reject & accept them.

We will set aside some class periods for you to present a working version of your idea for your paper in class.  This will give you a chance to get feedback from colleagues before you hand in the paper.  You’ll assign some readings and then basically share your conclusions.

The paper is due on May 8.

Schedule of Meetings

Spring 2008 Reading List

Other topics possibly covered in more detail in the student presentations:
Sexual selection of cognitive processes, infanticide, sex ratios, visual signals, sexual selection & sexually transmitted diseases, sexual selection & speciation, alternative reproductive strategies (e.g., sexual bimaturism, extra-pair copulations), sexual selection & cultural evolution, inferring sexual selection from fossil evidence.

For each meeting, the relevant sections of Setchell, J.M. & Kappeler (2003), hereafter simply “S&K” are indicated by referring to the parts of the outline of their paper that I present below.




Jan. 24
Organizational Meeting
Jan. 31
Basic Principles
Andersson, M.  1994.  Sexual Selection, Princeton University Press, Princeton.  Chapter 1.

S&K, Sections I, II, III, IV

Darwin, Darwin, C.  1871.  The Descent of Man, and Selection in Relation to Sex, 1st ed., J. Murray, London.  Chapter 8.

Clutton-Brock, T.H.  2004.  What is sexual selection?  In: Sexual Selection in Primates, (P.M. Kappeler & C.P. van Schaik, eds.), pp. 24-36.  Cambridge University Press, Cambridge.

Clutton-Brock, T.H.  2007.  Sexual selection in males and females.  Science, 318:1882-1885.
Feb. 7
Inrasexual Selection & Dimorphism in Primates
Andersson Chapters 11 & 12

S&K, Section V, Parts A, B, C1, C2, C3, C4, C7, F.

Thorén, S., Lindenfors, P. & Kappeler, P.M.  2006.  Phylogenetic analyses of dimorphism in primates: Evidence for stronger selection on canine size than on body size.  Am. J. Phys. Anthrop., 130:50-59.

Plavcan, J.M.  1998.  Correlated response, competition, and female canine size in primates.  Am. J. Phys. Anthrop., 107:401-416.

Caillaud, D., Levréro, F., Gatti, S., Ménard, N. & Raymond, M.  2008.  Influence of male morphology on male mating status and behavior during interunit encounters in western lowland gorillas.  Am. J. Phys. Anthrop., 00:00-00.
Feb. 14
Female Choice
S&K, Section VI, Parts A, B

Andersson, M. & Simmons, L.W.  2006.  Sexual selection and mate choice.  Trends Ecol. Evol., 21:296-302.

Fisher, R.A.  1958.  The Genetical Theory of Natural Selection, 2nd ed., Dover, New York.  Excerpt: "Sexual Selection", pp. 146-156.

Andersson, M.  1994.  Sexual Selection, Princeton University Press, Princeton.  Chapters 2, 3, 8
Feb. 21
Some Female Choice Data,
Indirect Benefts:

Genetic Compatibility
S&K, Section VI. Part B, C, D2, D3, DF

Hamilton, W.D. & Zuk, M.  1982.  Heritable true fitness and bright birds: A role for parasites?  Science, 218:384-387.

Mays, H.L.J. & Hill, G.E.  2004.  Choosing mates: Good genes versus genes that are a good fit.  Trends Ecol. Evol., 19:55-559.

Schwensow, N., Eberle, M. & Sommer, S.  2008.  Compatibility counts: MHC-associated mate choice in a wild promiscuous primates.  Proc. Roy. Soc. Lond. B, 275:555-564.

Sefcek, J.A. & King, J.E.  2007.  Chimpanzee facial symmetry: A biometric measure of chimpanzee health.  Am. J. Primatol., 69:1257-1263.

Stumpf, R. & Boesch, C.  2006.  The efficacy of female choice in chimpanzees of the Taï Forest, Côte d’Ivoire.  Behav. Ecol. Sociobiol., 60:749-765.
Feb. 28
Some Female Choice Data
Direct Benefits
S&K, Section VI, Part D1

Møller, A.P., & R. Thornhill. 1998. Male parental care, differential parental investment by females and sexual selection. Anim. Behav., 55:1507-1515.

E. W. Heymann.  2003.  Scent marking, paternal care, and sexual selection in Callitrichines.  In: Sexual Selection and Reproductive Competition in Primates: New Perspectives and Directions (C. Jones), pp. 305-325.  New York: American Society of Primatologists.

Griffith, S.C. & Sheldon, B.C.  2001.  Phenotypic plasticity in the expression of sexually selected traits: Neglected components of variation.  Anim. Behav., 61:987-993.

Palombit, R.A., Cheney, D.L. & Seyfarth, R.M.  2001.  Female-female competition for male “friends” in wild chacma baboons (Papio cynocephalus ursinus).  Anim. Behav., 61:1159-1171.
Mar. 6
Sexual Conflict
Arnqvist, G. & Rowe, L.  2005.  Sexual Conflict, Princeton University Press, Princeton. [Chapter 1]

Holland, B. & Rice, W.R.  1999.  Experimental removal of sexual selection reverses intersexual antagonistic coevolution and removes a reproductive load.  Proc. Nat. Acad. Sci., 96:5083-5088.

Foerster, K., Coulson, T., Sheldon, B.C., Pemberton, J.M., Clutton-Brock, T.H. & Loeske, E.B.K.  2007.  Sexually antagonistic genetic variation for fitness in red deer.  Nature, 447:1107-1110.

Cordero, C. & Eberhard, W.G.  2003.  Female choice of sexually antagonstic male adaptations: A critical review of some current research.  J. Evol. Biol., 16:1-6.

Muller, M.N., Kahlenberg, S.M. & Wrangham, R.W.  in press.  Male aggression against females in chimpanzees.  In: Male Aggression Against Females in Primates, (M.N. Muller & R.W. Wrangham, eds.), pp.  Harvard University Press, Cambridge, Massachusetts.

Position Papers due tomorrow March 7
Mar. 13
"Role reversed" systems
Clutton-Brock, T.H., Hodge, S.J., Russell, A.F., Jordan, N.R., Bennett, N.C., Sharpe, L.L. & Manser, M.B.  2006.  Intrasexual competition and sexual selection in cooperative mammals.  Nature, 444:1065-1068.

S&K: Section V, Parts D & E; Section VI, Part C2, F.

Engh, A.L. et al. (2002).  Reproductive skew among males in a female-dominated mammalian society.  Behav. Ecol. 13, 193-200.

Setchell, J.M. & Wickings, E.J.  2006.  Mate choice in male mandrills (Mandrillus sphinx)Ethology, 112:91-99.

LeBas, N.  2006.  Female finery is not for males.  Trends Ecol. Evol., 21:170-173.

Position Papers: Reviews of Zuk
Mar. 20
Spring Break
Mar. 27
Postcopulatory Mechanisms
Birkhead, T.R. & Pizzari, T.  2002.  Postcopulatory sexual selection.  Nature Reviews Genetics, 3:262-273.

S&K, Section V, Parts C5, C7, C8, C9; Section VI, Part E

Evans, J., Zane, L., Francescato, S. & Pilastro, A.  2003.  Directional postcopulatory sexual selection revealed by artificial insemination.  Nature, 421:360-363.

Dixson, A.  2002.  Sexual selection by cryptic female choice and the evolution of primate sexuality.  Evol. Anthro., Supplement 1:195-199.

Pradhan, G.R., Engelhardt, A., van Schaik, C.P. & Maestripieri, D.  2006.  The evolution of female copulation calls in primates: A review and a new model.  Behav. Ecol. Sociobiol., 59:333-343.
Apr 1
Student Presentations
Robert: Parental invetsment patterns in humans focusing on sexually antagonistic coevolution of males and females.

   Trivers, R.L. & Willard, D.E.  1973.  Natural selection of parental ability to vary the sex ratio of offspring.  Science, 179:90-92.

Rolando: Religion and sexual selection.
Robert & Rolando
Apr. 10
Student Presentations
Alison: Hormonal regulation of sexual dimorphism: Implications for sexual selection theory.

Nancy: Female choice for direct benefits in primates
Alison & Nancy
Apr. 17
Student Presentations
David: Sexual seletion & speciation

Jay: How material culture influences sexual selection: Stone artifacts among historic period peoples of the American Northwest

    Kohn, M. & Mithen, S.  1999.  Handaxes: Products of sexual selection?  Antiquity, 73:518-526.
David & Jay
Apr. 24
Student Presentations
Lisa: Costs imposed by males on female choice and how females cope with these costs.

   Bachmann, C. & Kummer, C.  1980.  Male assessment of female choice in hamadryas baboons.  Behav. Ecol. Sociobiol., 6:315-321.

Emily:  Sexual selection on cognition.
Schöning, S., Engelien, A., Kugel, H., Schäfer, S., Schiffbauer, H., Zwisterlood, P., Pletziger, E., Beizai, P., Kerstin, A., Ohrmann, P., Greb, R.R., Lehmann, W., Heindel, W., Arolt, V., and Konrad, C.  2007.  Functional anatomy of visuo-spatial working memory during mental rotation is influenced by sex, menstrual cycle, and sex steroid hormones.  Neuropsychologia, 45: 3203-3214.
Lisa & Emily
May 1
Student Presentation

Sexual Selection in Homo sapiens
Kristy Longpre: Olfactory cues & female mate choice.

Miller, G.F.  2007.  Sexual selection for moral virtues.  Q. Rev. Biol., 82:97-125.

Apostolou, M.  2007.  Sexual selection under parental choice: The role of parents in the evolution of human mating.  Evol. Hum. Behav., 28:403-409.

Wilson, C.G.  2008.  Male genital mutilation: An adaptation to sexual conflict.  Evol. Hum. Behav., 29:149-164.

Haufe, C.  2008.  Sexual selection and mate choice in evolutionary psychology.  Biol. Philos. 23:115-128.

Gangestad, S.W. & Simpson, J.A. 2000. The evolution of human mating: Trade-offs and strategic pluralism. Behav. Brain. Sci., 23: 573-644.


Other graduate seminars:

Biology of Social Bonds Primate Ecology & Social Behavior Methods in Field Primatology

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