Selfish Genes in Humans and Chimps
From New Scientist:
"These genes show signs of positive natural selection in both branches of the evolutionary tree and are changing more swiftly than would be expected through random mutation alone.
"...Cells carrying genes that hinder apoptosis [cell-death] have a greater chance of producing mature sperm cells, so Nielsen believes these genes can become widespread in populations over time.
But because primates also use apoptosis to eliminate cancerous cells, positive selection in this case may not be favourable for the mature animal: 'The selfish mutations that cause apoptosis avoidance may then also reduce the organism's ability to fight cancer,' Nielsen explains."
- New Scientist Article
So all those cancers everywhere are probably not the devil after all.