Endocrine- disrupting chemical (EDC) exposure can induce an epigenetic transgenerational reprogramming, with effects that differ between sexes, and this could have an evolutionary impact, because exposed individuals would not reproduce effectively; besides, exposure to EDCs during the embryonal stages provoke changes in behavior related to reproductive functions in the late adult individual. Then, the hypothesis would be that, if individuals have special preferences for mating, then an evolutionary impact may exist. To test this assumption, the authors studied the mating behavior of an F3 generation rats (n=12), descendants from an F0 group that was previously exposed to vinclozolin. After testing the mate preference behavior, they "found that all females preferred males from the control lineage [not exposed to vinclozolin but to DMSO], whereas males from both lineages exhibited no preferences for female type". They later repeated the experiments to minimize the effect of odor discrimination on behavior, and found that the "inability to discriminate among social odors [...] cannot account for the observed differences". Although the purpose of this paper was not to find a causal agent for this, the authors mentioned that many factors can be influential in this mate preference behavior, such as the MHC (HLA) variability, the exocrine gland- secreting peptide (ESP1), ultrasound emission, and others. They concluded that "the current study demonstrates that an environmental factor can promote a transgenerational alteration in the epigenome that influences sexual selection and could impact the viability of a population and evolution of the species." In my opinion, putting aside the fact that the purpose was not, for the moment, to establish a causal agent for the change in mate preference, I cannot help to think that the behaviour was "measured" using subjetive qualitative variables, while some other markers (biochemical, genetic, epigenetic, brain scan patterns, etc.) could be more informative -besides, I don't know for sure if twelve is a statistically significative number. Questions apart, the paper suggest an interesting principle of "perception of wealthness", that was long ago assumed by neodarwinists, but here from a neolamarckian perspective.
Crews, D. et al. 2007. Proc Natl Acad Sci USA 104(14):5942-5946
epigenetics
