Université Paris 1 Panthéon-Sorbonne

Actualités

 

 

Colloque : 

 

 

Sponsors :

Agence Nationale de la Recherche (Projet Biosex ANR-07-JCJC-0073-01)

Université Paris Ouest (Pôle 5 « L'humain en devenir », EA 373, ED 139).

Institut Universitaire de France

UMR 7205 OSEB Origine structure et évolution de la biodiversité, MNHN-CNRS-EPHE

 

 

 

 

 

Session 1 Historical issues, metaphysical commitments

 

Chair: Philippe Huneman (IHPST)

 

 

9h. Registration.

 

9h30-10h25 Marion Thomas (IRIST/DHVS, Université de Strasbourg)

Are females naturally finicky and males fickle? An appraisal of
histories of sexual selection and mate choice from Darwin to Wilson (1871-1975)

 

10h25-11h20- Michel Veuille (École Pratique des Hautes Études, Paris)

Why did Darwin reject Fisher's sex-ratio theory ?

 

 

11h20-12h15- Jean Gayon (IUF/IHPST, Université Paris I)

Sexual Selection in the French school of population genetics (Boesiger, Petit)

 

12h15-12h30. General discussion (1)

 

12h30-14h. Lunch break.

 

 

14h-14h55- Michael Ruse (Florida State University)

Caught in the Cross Fire? Sexual Selection and the Reductionism-Holism Debate

 

Session 2: Animal aesthetics ?

 

Chair: Michel Kreutzer (Université Paris Ouest)

 

 

14h55-15h50- Richard O. Prum (Yale University)

Sexual Selection and Evolutionary Aesthetics

 

 

15h50-16h45. Thierry Hoquet (University Paris Ouest)

What's wrong with animal aesthetics ?

 

 

16h45-17h. General discussion (2)

 

 

 

 

 

Session 3: More than competition?

 

Chair: Gérard Leboucher (Université Paris Ouest)

 

 

9h30-10h25 Nina Wedell (University of Exeter)

Sexual selection and selfish genetic elements

 

 

10h25-11h20- Tommaso Pizzari (Oxford University)

Evolutionary theory and sexual dynamics

 

11h20-12h15- Joan Roughgarden (Stanford University)

Teamwork, Bargaining, and Social Evolution

 

 

12h15-12h45. Pierre Henri Gouyon (MNHN)

Commentary.

 

12h45-13h. General discussion (3)

 

13h-14h30. Lunch break.

 

 

Session 4: Eager males, coy females? Challenging the old paradigm? 

 

Chair : Jean Gayon  (IUF, IHPST)

 

14h30-15h25- Frank Cézilly (IUF, Université de Bourgogne)

Female choice and sexual selection: new avenues for an old paradigm?

 

 

15h25-16h20- Malin Ah-King (Uppsala University)

Beyond the Darwin-Bateman paradigm:

The reaction norm of sex, flexible mate choice and the Switch-Point Theorem

 

 

16h20-17h. General discussion (4). Conclusions

 

 

 

 

 

Malin Ah-King, Uppsala University, & Patricia Gowaty, UCLA

 

Beyond the Darwin-Bateman paradigm:

The reaction norm of sex, flexible mate choice and the Switch-Point Theorem

 

Sex differences have been the focus of sexual selection theory since it was first formulated. However, sex in itself is variable and can even be considered a reaction norm. Variability in sex determination, sex change, sex differences in appearance and sexual behavior all corroborate this view of sex as a result of genetic and environmental influences on an already existing phenotype.       Choosy females and indiscriminate males constitute one of the central notions by traditional sexual selection theory, that is the Darwin-Bateman paradigm. However, accumulating empirical evidence shows that mate choice is flexible in response to environmental, social and internal factors. Here we put recent empirical evidence of flexible mate choice in diverse taxa in relation to a new dynamic theoretical framework, Gowaty and Hubbell's Switch-Point Theorem. While empirical studies have used trade-off hypotheses to explain each case of mate choice flexibility, such as predation risk, density, OSR, encounter rate, "chooser condition", the Switch-Point Theorem simplifies and unifies all or nearly all of these factors into the effects on five parameters that reflect constraints on individual time available for mating. We conclude by pointing out directions for future research in relation to this new dynamic unifying model of sexual selection.

 

 

 

Frank Cézilly, Morgan David & François-Xavier Dechaume-Moncharmont

Université de Bourgogne (UMR CNRS 5561), Institut Universitaire de France

 

Female choice and sexual selection: new avenues for an old paradigm?

 

The relevance of female choice for the evolution of sexual dimorphism was a strong point of disagreement between early evolutionary biologists, before it came to be widely accepted by the scientific community. Still, the evidence for female choice driving the evolution of secondary sexual characters in males deserves further consideration. In this talk I will address several methodological issues associated with the estimation of the importance of female choice in sexual selection, using new and original data on fish and bird species. I will first examine the relevance of the concept of personality to studies of sexual selection and mate choice. Then, I will present new data on rationality in female preference as assessed from transitivity. Finally, I will introduce a particular example of loss of sexual dichromatism as a challenge for the study of the role of female choice in the evolution of sexual dimorphism. 

 

 

Jean Gayon, IUF/IHPST, Université Paris I

Sexual Selection in the French school of population genetics (Boesiger, Petit)

 

Pierre-Henri Gouyon, MNHN, Paris

A commentary on J. Roughgarden's Genial Gene.

 

 

Thierry Hoquet, Université Paris Ouest

What's wrong with animal aesthetics ?

This paper attempts to survey a few objections that are raised against the idea of aesthetic pleasure as a proper incentive to animal behaviour. My presentation will try to review some of the main difficulties that the idea of an aesthetic sense in animals seems to encounter (beauty as an anthropomorphic projection, the question whether animals choose ? etc.). Finally, I will attempt to set some goals that a behavioural science of aesthetics should endorse.

 

 

Tommaso Pizzari, Oxford University

Evolutionary theory and sexual dynamics

 

Sexual selection is a cornerstone of neo-darwinian evolutionary theory. Over recent years however, sexual selection studies have ignited debate over the consequences of sexual selection for intersexual coevolutionary dynamics. At one end of the spectrum, the operation of sexual selection has been identified with sexual conflict. For example, Arnqvist & Rowe (2005) have argued that "the fit [between sexual conflict and sexual selection] is so good that it is entirely unclear whether a distinct boundary even exists between [...] sexual conflict and the body of theory on sexual selection" (p. 14). At the other end, it has been advocated that sexual selection theory should be replaced by a cooperative framework that is not entrenched in sexual conflict. For example, Roughgarden and colleagues (2006) have recently proposed that intersexual interactions as driven by "a sense of friendship [that] resides in animal bonding, a joy or synergy in the spirit of cooperation" (p. 966). In this talk, I review theory and empirical evidence for different evolutionary outcomes of sexual interactions: competition, cooperation, altruism and spite. I show that sexual selection has the potential to drive sexual dynamics towards all four of these scenarios. I make two conclusions. First, there is clearly more to sexual selection than selfish competition and conflict than often assumed. Second, current evolutionary theory (including sexual selection theory) provides a powerful heuristic to explain and predict all possible evolutionary scenarios of intersexual dynamics.

 

 

 

 

Richard O. Prum, Yale University

Sexual Selection and Evolutionary Aesthetics

 

Charles Darwin proposed sexual selection by mate choice as an evolutionary consequence of an innate, organismal "aesthetic faculty" or a "taste for the beautiful." Criticism by A. R. Wallace and others led to the complete abandonment of the aesthetic perspective in sexual selection. Wallace viewed any possible action of sexual selection as being subsumed within natural selection, and thus not worth recognizing as a separate evolutionary mechanism. Most contemporary sexual selection theory- in which natural selection acts on female preferences for honest quality indicator display traits- is intellectually Wallacean; only Wallace called it natural selection, and many contemporary theorist call it sexual selection. Recently, I have advocated that the Lande-Kirkpatrick sexual mechanism provides an appropriate null model of intersexual selection. Here, I argue that an intersexual selection theory that fully incorporates the L-K null closely captures the aesthetic evolutionary dynamics that Darwin intended. Although Darwin recognized that mating preferences could act on indicators of male quality, he was clear that there can be purely aesthetic/sensory consequences to displays and preference. Further, Darwin made unambiguous statements about the mutual coevolution of display traits and mating preferences. In the modern context, Evolutionary Aesthetics is the study of the coevolution of displays and mating preferences. Honest indicators are not excluded from evolutionary aesthetics. The study of sexual selection will greatly benefit from recognizing that display and preference can evolve unhindered by natural selection on preferences. Sexual selection establishes an independent and frequently arbitrary, normative attractiveness, or beauty, in each population. Other evolutionary aesthetic processes include the evolution of flowers and fruit advertisements.

 

 

 

Joan Roughgarden, Stanford University

Teamwork, Bargaining, and Social Evolution

 

The now-classical picture of social evolution from the 1960-70's relied on the hypotheses of kin selection, group selection, and reciprocal altruism to explain the evolution of altruism (and cooperation), together with the hypotheses of competition for mates with good genes followed by parental conflict of interest to explain the evolution of family organization. This picture has been dissolving in light of continuing empirical and theoretical discoveries. New approaches to the evolution of cooperation and family life are offered by Nash Bargaining Theory for modelling biological "teamwork", and by the notion biological "firms" for producing offspring. How evolutionary biology regroups to assimilate new approaches will determine whether it prospers or ossifies during the foreseeable future.

 

 

Michael Ruse, Florida State University

Caught in the Cross Fire? Sexual Selection and the Reductionism-Holism Debate

The late Stephen Toulmin spoke of science as being governed by what he called "ideals of natural order." These are metaphysical presuppositions that we bring to our understanding of science, imposed in a Kantian way rather than read from experience. They are akin to Kuhnian paradigms, but unlike paradigms can persist across scientific revolutions, and a scientific community can have supporters of rival ideals that persist nigh indefinitely. I look upon reductionism and holism as two such (rival) ideals, and I believe they have separated biologists perhaps even back as far as the Greeks. I want to explore the possibility that the controversies over sexual selection are primarily differences about these ideals, rather than other matters like sexism, and that taking such an approach makes clear otherwise puzzling aspects of history.

 

 

 

 

Marion Thomas, IRIST/DHVS, Université de Strasbourg

Are females naturally finicky and males fickle? An appraisal of
histories of sexual selection and mate choice from Darwin to Wilson (1871-1975)

In 1868, three years before publishing The Descent of Man, and Selection in Relation to Sex, Charles Darwin wrote to his friend and fellow naturalist Alfred Wallace that sexual selection drove him "half mad" because of the "number of collateral points which require investigation". Erika Milam's book Looking for a Few Good Males, Female Choice in Evolutionary Biology(2010)definitely echoes Darwin's remark, by retrieving the complicated and controversial fate of sexual selection and female choice throughout the 20th century. Drawing on Milam's book and other accounts, I will show how the works of biologists (Darwin, Huxley, Fisher, Tinbergen, Petit and Wilson) on sexual selection offer a unique vantage point to investigate intellectual debates, disciplinary divides and social developments of the 20th century life sciences. I will particularly illustrate how the topic of female choice encapsulates different epistemological questions like the animal-human boundary, the question of practice and place of research and the question of animal model. Supplementing Milam's study, I will also examine how scientists' understanding of sexual selection were informed by socio-political and cultural values of their time. For instance, I will explore how Fisher's interest in eugenics and Huxley's commitment to the feminist cause shaped their work on animal courtship behaviour.

 

 

Michel Veuille, Ecole Pratique des Hautes Etudes, Paris, France

Why did Darwin reject Fisher's sex-ratio theory ?

 

A recurrent problem which Darwin had to solve was whether his sexual selection theory was contradicted by the equal proportions of males and females in most species. In his Descent of Man (1871) he brilliantly presented, in his own words, the mechanisms later put forward by Fisher (1930) whereby selection for the fertility of progeny favors individuals producing sons and daughters in equal proportions, weighted by the cost of producing either sex. In the 1874 edition he replaced this part (the biggest change in the book) by an obscure discussion on how infanticide could increase inherited biases in human sex-ratio. The paradox of the 1:1 sex-ratio mirrors another of Darwin's promising hypotheses, that of the mutual selection of males and females for the most vigorous mates. Darwin seems to confuse the intensity of sexual selection, and the extent of its asymmetry between males and females. I will explore this, in relation with Darwin's erroneous hypotheses on inheritance and the expected link between external traits and heredity in pre-Mendelian thought.

 

 

Nina Wedell, University of Exeter

Sexual selection and selfish genetic elements

 

One aspect of sexual selection that Darwin was completely unaware of was the role of Selfish Genetic Elements (SGEs). SGEs are genes, organelles or microorganims present within the genome or cell of an organism that spread through populations by subverting normal patterns of inheritance in ways that increase their representation in the next generation. SGEs are ubiquitous in living organisms and despite their dramatic ability to manipulate host reproduction including the frequent reduction in male fertility their impact on sexual selection remains little explored. I will demonstrate the power of SGEs as an agent of sexual selection and show they can have remarkably wide-ranging impacts on male and female reproduction.

 

 

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Atelier de lecture : Deux, dualismes, duos, duels, dyades 

 

Atelier de lecture du Département de philosophie Université Paris Ouest Nanterre La Défense. 

 
Organisé par Martine de Gaudemar et Thierry Hoquet.

 

Horaire : le mardi soir de 17h à 19h.

Lieu : U. Paris Ouest Nanterre La Défense (RER Nanterre Université).
Bâtiment L. Salle à préciser.

 

Prochaine séance : Mardi 03 mai 2011, salle L420 ou L421

 

Séance animée par Lucie Laplane

Lecture: les travaux de Thomas Pradeu sur la philosophie de l'immunologie

 

Programme Complet

 

 

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 Vient de paraître 

 

Ilana Löwy 

Löwy, Ilana. 2010. Preventive Strikes. Women, Precancer, and Prophylactic Surgery. Baltimore, Johns Hopkins University Press.  voir pdf

 

Helga Satzinger

Satzinger, Helga. 2009. Differenz und Vererbung. Geschlechterordnungen in der Genetik und Hormonforschung 1890-1950. Böhlau: Köln, Weimar, Wien.
www.boehlau.at/978-3-412-20339-9.html

 

 

 

• Autres événements

 

 

 

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 Call for papers 

à envoyer avant le 01/05/2010

 

Call for papers :

 

CHALLENGING POPULAR MYTHS OF SEX, GENDER AND BIOLOGY