This coming lab meeting (Tuesday April 29th), we
will discuss sexual selection and sexual conflict on the chromosome level. I
have chosen a paper that deals with mito-sex chromosome interactions,
inter-genomic coadaptation and conflict. Looking forward to some interesting
Authors: Rebecca Dean, Fabian Zimmer and Judith E. Mank
Abstract: Mitochondrial interactions with the nuclear genome
represent one of life’s most important coevolved mutualisms. In many organisms,
mitochondria are maternally inherited, and in these cases, co-transmission
between the mitochondrial and nuclear genes differs across different parts of
the nuclear genome, with genes on the X chromosome having 2/3 probability of
co-transmission, compared to 1/2 for genes on autosomes. These asymmetrical
inheritance patterns of mitochondria and different parts of the nuclear genome
have the potential to put certain gene combinations in inter-genomic
coadaptation or conflict. Previous work in mammals found strong evidence that
the X chromosome has a dearth of genes that interact with the mitochondria
(mito-nuclear genes), suggesting that inter-genomic conflict might drive genes
off the X onto the autosomes for their male-beneficial effects. Here, we
developed this idea to test co-adaptation and conflict between mito-nuclear
gene combinations across phylogenetically independent sex chromosomes on a far
broader scale. We found that, in addition to therian mammals, only C. elegans
showed an under-representation of mito-nuclear genes on the sex chromosomes.
The remaining species studied showed no overall bias in their distribution of
mito-nuclear genes. We discuss possible factors other than inter-genomic
conflict that might drive the genomic distribution of mito- nuclear genes.
In Argumentet (Ecology Building 2nd floor) at
11:30 – 12 as usual. I will bring fika!
Poison dart frog (Dendrobates pumilo) in Costa Rica 2005
(Photo: Erik Svensson)
Posted by Erik Svensson
This coming lab-meeting next week, we will listen to an informal presentation on poison dart frogs and colour polymorphism by visiting student Beatriz Willink, who will soon hopefully join the EXEB-lab as a new PhD-student. Beatriz has done a three-years Master's in Costa Rica, and is an experienced field biologist. Some of Beatriz work has been published in Evolution, Evolutionary Ecology and Behavioural Ecology and Sociobology, and you can follow these links if you want to take a look at her papers.
The title of Beatriz talk is:
"Not everything is black and white: Multiple predators and predator-avoidance strategies in a polytypic poison frog"
Time and place:
When: Tuesday, April 22, at 10.30 Where: "Darwin Room", 2nd floor, Ecology Building Any fika volunteer?
Common frog (Rana temporaria). Photo by Erik Svensson
Posted by Erik Svensson
It is spring time, and some of you have already noted the frogs that mate in the pond outside the Ecology Building. Then it seems highly timely to discuss some classical problems in ecology and evolutionary biology that have been subject to some previous lab-meetings, but which continue to fascinate many (including me): why are there more species in the tropics?
Is it because of evolutionary history, such as higher speciation rates in the tropics or lower extinction rates over millions of years? Or is it mainly due to ecological factors such as more energy through the sun and higher humidity in the tropics? Or a combination of ecological and evolutionary factors? What about the roles of niche conservatism and diversity dependence, and how do these affect tropical and temperate diversity?
We will discuss a recent paper about this by Alexander Pyronand John Wiens about latitudinal diversity gradients in amphibians in relation to speciation, extinction and phylogeny. You can find the paper here, and it is a phylogenetic comparative study, and the abstract is appended below.
When: Tuesday, April 15, at 10.30 Where: "Argumentet", 2nd floor, Ecology Building.