Since this is a fairly common discussion and or interest, I thought this might be an interesting read for those that are curious.

 

http://www.biomedcentral.com/news/20040527/01/

 

PS. Not sure if this is supposed to be in the news section or not, but since my last erroneous go at it, I'm feeling a bit reluctant of placing it there.

It doesn't really surprise me, even with small % differences of genetic sequences, you would expect most genes to vary (in this case 83%) because these small differences should be spread evenly. According to the paper, there's 2-3% genes that have changed enough to say they have 'adaptively radiated', and so stating that the 1.2% sequence difference has a big effect in terms of protein structure it doesn't really seem backed up if only 2-3% of genes show significant adaptive radiation.