Dear colleagues, We would like to draw your attention to the following review on speciation patterns in killer whales (*Orcinus orca*), published in the May issue of the Biological Journal of the Linnean Society: Riesch R, Barrett-Lennard LG, Ellis GM, Ford JKB and Deecke VB (2012) Cultural traditions and the evolution of reproductive isolation: ecological speciation in killer whales? *Biol J Linn Soc **106(1)*:1–17, DOI: 10.1111/j.1095-8312.2012.01872.x ABSTRACT Human evolution has clearly been shaped by gene-culture interactions, and there is growing evidence that similar processes also act on populations of non-human animals. Recent theoretical studies have shown that culture can be an important evolutionary mechanism because of the ability of cultural traits to spread rapidly vertically, obliquely, and horizontally, resulting in decreased within-group variance and increased between-group variance. Here, we collate the extensive literature on population divergence in killer whales (*Orcinus orca*), and argue that they are undergoing ecological speciation as a result of dietary specializations. Although we cannot exclude the possibility that cultural divergence pre-dates ecological divergence, we propose that cultural differences in the form of learned behaviours between ecologically divergent killer whale populations have resulted in sufficient reproductive isolation even in sympatry to lead to incipient speciation. KEYWORDS: Cetacea, culture, cultural evolution, gene-culture coevolution, vocal dialects Please feel free to contact me with any questions about this review ( rwriesch.evolutionarybiology@gmail.com). Best regards Rüdiger ----------------------------- Rüdiger Riesch, PhD Postdoctoral Researcher North Carolina State University Department of Biology & W. M. Keck Center for Behavioral Biology Raleigh, NC 27695-7617 USA Phone: 919-513-7552 Email: rwriesch.evolutionarybiology@gmail.com homepage: http://gambusia.zo.ncsu.edu/riesch/Home.html "The most exciting phrase to hear in science, the one that heralds the most discoveries, is not "Eureka" but "That's funny..." ––Isaac Asimov