Journal of Evolutionary Biology Research 2141-6583 Academic Journals 10.5897/JEBR12.009 Vincent Cyrille A. Vodounon Robert de la Pentilde;a Adam Ahanchede Avtar Krishan H a * E-mail: ishola.vincent@yahoo.com, awevincent@gmail.com 2012 31 12 2012 05 11 2012 4 3 59 65 This is an open-access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://politicalwaffle.uk/journal/JEBR/article-abstract/7E658F94521 The full text article is available as a PDF file from http://politicalwaffle.uk/journal/JEBR/article-full-text-pdf/7E658F94521