Question 20.7: Yeast regulatory genes
----Guelzim, N., S. Bottani, P. Bourgine and F. Képès. 2002. Nature Genetics 31: 60-63.
Question 20.8:Silverswords
----inferred from Baldwin, B. G. and M. J. Sanderson 1998. Proceedings of the National Academy of Sciences (USA) 95: 9402–9406.
Question 20.15: Vole dispersal
----Sandell, M., J. Agrell, S. Erlinge, and J. Nelson. 1991. Oecologia 86: 153-158.
Question 20.18: Bee lifespans
----inferred from Visscher, P. K. and R. Dukas. 1997. Insectes Sociaux 44: 1-5.