title: Xmrks the spot: life history tradeoffs,  sexual selection and the evolutionary  ecology of oncogenesis.
abstract: In a classic paper, George Williams (1957) argued that alleles promoting reproductive success early in life may be favoured by selection, even if they reduce the lifespan of individuals that bear the allele. A variety of evidence supports the theory that such 'antagonistic pleiotropy' is a major factor contributing to the evolution of senescence (Ljubuncic & Reznick 2009), but examples of specific alleles known to fulfil Williams' criteria remain rare, in both humans and other animals (e.g. Alexander et al. 2007; Kulminski et al. 2010). An intriguing example in this issue of Molecular Ecology (Fernandez & Bowser 2010) demonstrates that both natural and sexual selection may favour melanoma-promoting oncogene alleles in the fish genus Xiphophorus.
authors.affiliation: Department of Biology, East Carolina University, Greenville, NC 27858, USA. summersk@ecu.edu
authors.forename: Kyle
authors.initials: K
authors.lastname: Summers
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Crespi
mesh_terms: D000483:Alleles; D000818:Animals; D003532:Cyprinodontiformes / Q000235:genetics*; D019143:Evolution, Molecular; D005260:Female; D029941:Fish Proteins / Q000235:genetics*; D005787:Gene Frequency; D008297:Male; D052586:Mating Preference, Animal; D008545:Melanoma / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D012641:Selection, Genetic
chemical_list: D029941:Fish Proteins; D011518:Proto-Oncogene Proteins; D020794:Receptor Protein-Tyrosine Kinases; C077101:Xmrk protein, Xiphophorus