SFU’s Issues and Experts and SFU News have featured a recent study by Dan Greenberg and Arne Mooers.
From the reports: “A new study by Simon Fraser University biologists Dan Greenberg and Arne Mooers offers clues to why more than 30 per cent of amphibians, including frogs, newts, toads and salamanders, are at risk of extinction.
The researchers examined evolutionary patterns of modern extinction risk across more than 300 amphibian groups and found that species from groups with high ongoing diversification are at greater risk of extinction than slowly diversifying lineages. The research is published this month in the journal Evolution Letters.”
Click on the links below for more information and a link to the article:
The Faculty of Science Research News page has posted a summary of a recent paper by Felix Breden and colleagues, “Choosey female guppies select for more colourful males with bigger Y chromosomes” published in Nature Communications.
A study led by graduate students Alannah Biega and Dan Greenberg with post doctoral researcher Tom Martin, from the Arne Mooers lab, is the feature article in this month’s (April 2017) edition of Animal Conservation. They consider how well Zoos are doing at representing frogs and salamanders of conservation concern in their collections. As the “feature” article, the paper graces the cover, and there are three scholarly commentaries and a response discussing the role of zoos in mitigating global amphibian declines.
Article by the University of Jyväskylä highlighting Dr. Mokkonen’s work:
Men are from mars and women are from venus? Whiles this stereotype is extreme and controversial, gender differences in behaviour nonetheless are common in nature. Much variation in animal, including human, behaviour is regulated by expression of hormones and their receptors in brains.
For some animals, differences in the expression of vasopressin receptor 1a (Avpr1a) and oxytocin receptor (Oxtr) generates diversity in social and sexual behaviour; in humans, genetic differences at the gene for Avpr1a have been associated with marital problems. What is not clear, however, is why should the behaviour of individuals differ? And, if one type of behaviour is beneficial then why don’t all individuals express that behaviour?
A study published in Proceedings of the National Academy of Sciences (PNAS) asks the question: what mechanisms might maintain genetic differences in Avpr1a and Oxtr? The authors determined how genetic differences at these two genes associated with sexual behaviour affected the reproductive success (how many pups were born) of a small rodent, the bank vole Myodes glareolus.
The main result of the study was that the ‘beneficial’ genetic variants (alleles) at the vasopressin and oxytocin receptor genes depend on gender: in other word, alleles that are beneficial to the reproductive success of females are detrimental to success of males, and vice versa – this apparent conflict of interest between sexes is termed ‘sexually antagonistic selection’. Interestingly, the pattern of sexual conflict depended upon the social environment (the density of individuals). Changes in density of individuals, in space and time, often occur in nature, and this might be another important mechanism maintaining genetic and behavioural variation.
In the case of vasopressin and oxytocin receptors, there is a constant ‘battle’ to find a genetic optima, with diversity is maintained as no single optimal genetic variant (allele) for both sexes exits, and this is further complicated by environment change! While male and female bank voles do not come from different planets, they illustrate a potential ‘genetic battle’ that can happen as the sexes share the same genome but can nonetheless favour different behaviors.
Many behaviours are regulated by vasopressin and oxytocin receptor in other mammals and in humans. The new research raises an interesting question: is the evolution of our brains also regulated by a conflict between sexes?
More information: Eija Lonn et al. Balancing selection maintains polymorphisms at neurogenetic loci in field experiments, Proceedings of the National Academy of Sciences (2017). DOI: 10.1073/pnas.1621228114