Stochastic epigenetic variation as a driving force of development, evolutionary adaptation, and disease

Darwin's theory of evolution is based on the natural selection of genetic variations caused by random mutations. On the other hand, Lamarck suggested that phenotypes are shaped by nature and each individual striving to improve for survival. This paper proposes an alternative theory for evolutionary adaptation based on epigenetics. Epigenetic variations, such as varying DNA methylation patterns, that do not modify the phenotype could nevertheless affect its variability and that increased variability may in turn improve fitness and be passed on. The paper provides two experimental results to support their claims. Firstly, the variations in the extent of DNA methylation in the brain constitute evidence in support of stochastic or random epigenetic variation. Secondly, the loss or gain of CpG dinucleotides over time suggests a transmissible genetic mechanism for DNA methylation.


Christophe Boulay


Feinberg, A. P. and R. A. Irizarry (2010). "Stochastic epigenetic variation as a driving force of development, evolutionary adaptation, and disease." Proceedings of the National Academy of Sciences of the United States of America 107: 1757-1764.