A whole bunch of papers got published on PLoS-ONE yesterday. I did not have time to check them out very closely yet, but a few titles immediatelly caught my attention:
High Costs of Female Choice in a Lekking Lizard
by Maren N. Vitousek, Mark A. Mitchell, Anthony J. Woakes, Michael D. Niemack and Martin Wikelski
The cost to males of producing elaborate mating displays is well established, but the energy females spend on mate choice is less clear. This study monitored the heart rates of female Galápagos marine iguanas (Amblyrhynchus cristatus) and found they expended almost a days’ worth of energy a month choosing a mate. More choosy females lost weight, produced smaller follicles, and were less likely to survive El Niño years.
Female Sexual Polymorphism and Fecundity Consequences of Male Mating Harassment in the Wild
by Thomas P. Gosden and Erik I. Svensson
Genetic and phenotypic variation in female response towards male mating attempts has been found in several laboratory studies, demonstrating sexually antagonistic co-evolution driven by mating costs on female fitness. Theoretical models suggest that the type and degree of genetic variation in female resistance could affect the evolutionary outcome of sexually antagonistic mating interactions, resulting in either rapid development of reproductive isolation and speciation or genetic clustering and female sexual polymorphisms. However, evidence for genetic variation of this kind in natural populations of non-model organisms is very limited. Likewise, we lack knowledge on female fecundity-consequences of matings and the degree of male mating harassment in natural settings. Here we present such data from natural populations of a colour polymorphic damselfly. Using a novel experimental technique of colour dusting males in the field, we show that heritable female colour morphs differ in their propensity to accept male mating attempts. These morphs also differ in their degree of resistance towards male mating attempts, the number of realized matings and in their fecundity-tolerance to matings and mating attempts. These results show that there may be genetic variation in both resistance and tolerance to male mating attempts (fitness consequences of matings) in natural populations, similar to the situation in plant-pathogen resistance systems. Male mating harassment could promote the maintenance of a sexual mating polymorphism in females, one of few empirical examples of sympatric genetic clusters maintained by sexual conflict.
Interethnic Differences in Muscle, Liver and Abdominal Fat Partitioning in Obese Adolescents
by David Liska, Sylvie Dufour, Tosca L. Zern, Sara Taksali, Anna M.G. Calí, James Dziura, Gerald I. Shulman, Bridget M. Pierpont and Sonia Caprio
Our study indicates that obese Hispanic adolescents have a greater IMCL lipid content than both Caucasians and African Americans, of comparable weight, age and gender. Excessive accumulation of fat in the liver was found in both Caucasian and Hispanic groups as opposed to virtually undetectable levels in the African Americans. Thus, irrespective of obesity, there seem to be some clear ethnic differences in the amount of lipid accumulated in skeletal muscle, liver and abdominal cavity.
As always, if you read the papers and have questions or comments, post them at the paper, not on this post.