61 research outputs found
From Preferred to Actual Mate Characteristics: The Case of Human Body Shape
The way individuals pair to produce reproductive units is a major factor determining evolution. This process is complex because it is determined not only by individual mating preferences, but also by numerous other factors such as competition between mates. Consequently, preferred and actual characteristics of mates obtained should differ, but this has rarely been addressed. We simultaneously measured mating preferences for stature, body mass, and body mass index, and recorded corresponding actual partner's characteristics for 116 human couples from France. Results show that preferred and actual partner's characteristics differ for male judges, but not for females. In addition, while the correlation between all preferred and actual partner's characteristics appeared to be weak for female judges, it was strong for males: while men prefer women slimmer than their actual partner, those who prefer the slimmest women also have partners who are slimmer than average. This study therefore suggests that the influences of preferences on pair formation can be sex-specific. It also illustrates that this process can lead to unexpected results on the real influences of mating preferences: traits considered as highly influencing attractiveness do not necessarily have a strong influence on the actual pairing, the reverse being also possible
Evolutionary implications of heterochromatin and rDNA in chromosome number and genome size changes during dysploidy: a case study in Reichardia genus
In this study we showed that constitutive heterochromatin, GC-rich DNA and rDNA are implicated in chromosomal rearrangements during the basic chromosome number changing (dysploidy) in Reichardia genus. This small Mediterranean genus comprises 8-10 species and presents three basic chromosome numbers (x = 9, 8 and 7). To assess genome evolution and differentiation processes, studies were conducted in a dysploid series of six species: R. dichotoma, R. macrophylla and R. albanica (2n = 18), R. tingitana and R. gaditana (2n = 16), and R. picroides (2n = 14). The molecular phylogeny reconstruction comprised three additional species (R. crystallina and R. ligulata, 2n = 16 and R. intermedia, 2n = 14). Our results indicate that the way of dysploidy is descending. During this process, a positive correlation was observed between chromosome number and genome size, rDNA loci number and pollen size, although only the correlation between chromosome number and genome size is still recovered significant once considering the phylogenetic effect. Fluorescent in situ hybridisation also evidenced changes in number, position and organisation of two rDNA families (35S and 5S), including the reduction of loci number and, consequently, reduction in the number of secondary constrictions and nuclear organising regions from three to one per diploid genome. The potential mechanisms of chromosomal and genome evolution, strongly implicating heterochromatin, are proposed and discussed, with particular consideration for Reichardia genus
Système génétique, polymorphisme neutre et sélectionné : implications en biologie de la conservation
Organisation et fonctionnement hydrobiologique d'écosystèmes estuariens tropicaux (variabilité spatio-temporelle)
MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF
Meeting the biocalculus challenges: a reflection on didactic transposition processes in a cross-disciplinary context
International audienceUnderstanding how the contents of university mathematics education (UME) came to be what they currently are, as well as how they evolve (or are submitted to inertia) under various sorts of institutional conditions and constraints is an endeavor undertaken by the Anthropological Theory of the Didactic (ATD) under the name didactic transposition. In this paper, we present a reflexive analysis of transposition processes that we participated in when the first author (a mathematician and UME researcher) was given the responsibility of teaching and orchestrating a biocalculus course for more than 700 first-year biology students tutored by 10 mathematics instructors. The course material was developed on the basis of the official syllabus and materials provided by the second author, an evolutionary anthropologist familiar with quantitative approaches in biology. Didactic transposition processes will be modeled and discussed using ATD theoretical constructs in order to provide answers to the following research questions: What set of conditions and constraints allowed the emergence of a biocalculus course at the University of Montpellier (UM, France)? What are the characteristics of the transposition phenomena that took place, as compared to a more classical calculus course (such as the one that preceded it in Montpellier)
Modalités écologiques et évolutives des interactions entre les nématodes entomopathogènes Steinernema et leurs symbiotes bactériens Xenorhabdus
MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF
Histoire évolutive de deux espèces de cochevis ("Galerida Cristata" et "G. Theklae")
MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF
Meeting the biocalculus challenges: a reflection on didactic transposition processes in a cross-disciplinary context
International audienceUnderstanding how the contents of university mathematics education (UME) came to be what they currently are, as well as how they evolve (or are submitted to inertia) under various sorts of institutional conditions and constraints is an endeavor undertaken by the Anthropological Theory of the Didactic (ATD) under the name didactic transposition. In this paper, we present a reflexive analysis of transposition processes that we participated in when the first author (a mathematician and UME researcher) was given the responsibility of teaching and orchestrating a biocalculus course for more than 700 first-year biology students tutored by 10 mathematics instructors. The course material was developed on the basis of the official syllabus and materials provided by the second author, an evolutionary anthropologist familiar with quantitative approaches in biology. Didactic transposition processes will be modeled and discussed using ATD theoretical constructs in order to provide answers to the following research questions: What set of conditions and constraints allowed the emergence of a biocalculus course at the University of Montpellier (UM, France)? What are the characteristics of the transposition phenomena that took place, as compared to a more classical calculus course (such as the one that preceded it in Montpellier)
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