title: Evolutionary conflict: sperm wars, phantom inseminations.
abstract: A new experimental study has provided the first definitive evidence for conditional punishment of 'cheats' in a sperm-trading simultaneous hermaphrodite: the sea slug Chelidonura hirundinina. This also provides a rare unequivocal example of conditional reciprocity averting a 'tragedy of the commons' in biology.
authors.affiliation: Centre for Ecology & Conservation, University of Exeter in Cornwall, Penryn, UK. sashadall@iname.com
authors.forename: Sasha R X
authors.initials: SR
authors.lastname: Dall
authors.forename: Nina
authors.initials: N
authors.lastname: Wedell
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003220:Conflict, Psychological; D049851:Gastropoda / Q000502:physiology*; D008297:Male; D050090:Ovotesticular Disorders of Sex Development; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013094:Spermatozoa / Q000502:physiology*