As some of you know, Dr. Henry Heng visited Carleton this week and spoke about cancer biology. Cancer biology might seem like it has little to do with the levels of selection debate. However, I found his talk very relevant. In short, he has found that cancer evolution occurs at the genome rather than the gene level. I'm not an expert in this area, but I understand that many genes are involved in the development of cancer and that these genes are different for every individual. He has also found that during cancer development, the chromosomes become "mixed up" and these changes are responsible for cancer development. His studies of cell cultures have also shown that cancer cells go through two stages: an unstable macro-evolutionary stage where random changes occur and new "species" of cells are created and a more stable anagenesis-like stage where a single population of cells survives the chaos stage. Dr. Heng has therefore concluded that the key to cancer biology lies with the study of the genome.
In our last discussion, we explored the possibility of selection at the gene, individual, population, species, clade etc. levels. Dr. Heng's work excludes at least one of these possibilities. The genes cannot be the level of selection because genes don't work independently, they are part of a coordinated system. Dr. Heng demonstrates that the entire genome is under selection during cancer development but that the individual genes are not. Perhaps we can put gene selection to bed?
All potential errors of interpretation or of the description of Dr. Heng's work are my own.
Links to Dr. Heng's relevant publications (the first is especially relevant in the discussion of the levels of selection):
http://onlinelibrary.wiley.com/doi/10.1002/bies.200800182/abstract?userIsAuthenticated=false&deniedAccessCustomisedMessage=
http://onlinelibrary.wiley.com/doi/10.1002/jcb.22497/abstract;jsessionid=9122184DEAB05136AC78170B4F529ED5.d03t02?userIsAuthenticated=false&deniedAccessCustomisedMessage=
http://www.ncbi.nlm.nih.gov/pubmed/21640814
