Weiner, J. (1994). The Beak of the Finch. London: Cape.

Werren, J. H., Nur, U. & Wu, C.-I. (1988). Selfish genetic elements. Trends in Ecology & Evolution 3, 297–302.

Williams, G. C. (1985). A defence of reductionism in evolutionary biology. In Oxford Surveys in Evolutionary Biology (eds R. Dawkins & M. Ridley), pp. 1-27. Oxford: Oxford University Press.

Williams, G. C. (1992). Natural Selection: Domains, Levels and

Challenges. Oxford: Oxford University Press.

Williams, G. C. (1997). Plan and Purpose in Nature. London: Weidenfeld &

Nicolson.

Wills, C. (1990). The Wisdom of the Genes. New York: Basic Books.

Zahavi, A. & Zahavi, A. (1997). The Handicap Principle. Oxford: Oxford University Press.