References:
Elena, S. F. (june 26, 2003). Environmental stress and the effects of mutation. Journal of Biology, 2(2), 12th ser., 12.2-12.4. Retrieved April 05, 2016, from http://download.springer.com/static/pdf/834/art%3A10.1186%2F1475-4924-2-12.pdf?originUrl=http://jbiol.biomedcentral.com/article/10.1186/1475-4924-2-12&token2=exp=1460744982~acl=/static/pdf/834/art%253A10.1186%252F1475-4924-2-12.pdf*~hmac=7506036283fe89517540356de7f53878ae45e853ebe17d720a99c3467a7ad9c6
“Evolutionary History Is More than Skin Deep.” Evolutionary History Is More than Skin Deep. Web. 10 Apr. 2016.
Spencer, C. Evolution by Natural Selection & Phylogenetic Trees. (2014). Written by: Chrissy Spencer on August 15, 2014. Last revised by: Jung Choi on February 10, 2016. Retrieved April 05, 2016, from http://bio1510.biology.gatech.edu/module-1-evolution/evolution-by-natural-selection/
