Although I study conflict, I like to avoid it in real life, and in my professional work. However, I recently had a small dispute over a recent paper of mine. In brief, Phil Hedrick considered it incorrect to discuss ‘inbreeding’ at haploid, uni-parentally inherited loci. Here I briefly review my original paper, Hedrick’s comment, and our response. On the whole I think the debate was fun, although I’d rather be doing science than nitpicking about words, it is important that scientists form a common language to best communicate with one another and the greater community.
Mother’s curse – or ‘What’s in it for a mitochondrion in a male’: Since anything that is strictly inherited maternally is never transmitted by males, it seems like mitochondrial influences male fitness should be invisible to selection. This has been called ‘Mother’s curse’ by Gemmell et al, and Frank and Hurst argued that it may explain some diseases that preferentially strike males and may involve the mitochondria (e.g. Leber’s hereditary optic neuropathy).
Reversing Mother’s curse: The idea of mothers’ curse seems compelling, but my graduate co-advisor, Mike Wade and I thought that some proceses could reverse mother’s curse. Specifically, we argued that when maternal sibs depend on each other for help (i.e. kin selection) or mating (i.e. inbreeding) the success of a mitochondria in a female may depend on her brother. We argued that this indirect selection could act to maintain mitochondrial which function well in males. At the same time my friend, Rob Unckless and his collaborator Jeremy K. Herren came to the same conclusion.
Inbreeding and mitochondria: Recently, Phil Hedrick argued that since mitochondria are haploid, individuals cannot inbreed at mitochondrial loci. His argument is based on a common definition of the inbreeding level as the deviation in genotype frequencies from Hardy-Weinberg expectations (i.e. binomial sampling). With this definition of inbreeding, we cannot measure inbreeding at haploid loci, and therefore mitochondria cannot be inbred. Although this makes some sense, we countered that individuals cannot be inbred at haploid loci, they can inbreed with respect to mitochondrial loci. That is we consider mating between relatives tobe inbreeding, while Hedrick considers the deviation from Hardy Weinberg to be inbreeding. In our response we pointed out a few benefits of our ‘process’ rather than ‘outcome’ – oriented approach.