Via freedom to coercion: The emergence of costly punishment.
Hauert C, Traulsen A, Brandt H, Nowak M A, Sigmund K (2007); Science, 316(5833):1905-1907. doi: 10.1126/science.1141588
Diversity, relative abundance, and metabolic potential of bacterial endosymbionts in three Bathymodiolus mussel species from cold seeps in the Gulf of Mexico.
Molecular diversity at 18 loci in 321 wild and 92 domesticate lines reveal no reduction of nucleotide diversity during Triticum monococcum (Einkorn) domestication: implications for the origin of agriculture.