One of my interests is epigenetics.*
Below is a video explaining in simple terms for a general audience how changing epigenetics over time can offer one reason why identical twins grow different as they age. Considering that this is a fairly complex topic, I think this is a pretty good effort to explain the basic concepts.
For those that want a little more detail…** Epigenetic control of genes determines what genes are used in different parts of the body through controlling if a gene is unpacked and open to be ’read’, or packaged away. The packing state of a gene is determined, in part, by modifications of the DNA bases, the ‘epigenetic tags’ referred to in the video.
A slightly more technical summary is given by George Martin in his commentary Epigenetic drift in aging identical twins*** before he goes on to discuss some of his concerns with a paper presenting evidence for this effect in the same publication. (Both open access.)
* For the more technically-inclined my interests are mainly with chromatin structure, i.e. with the role of nucleosomes and higher-order structures in the control of gene expression. (I also have many other interests in computational biology, some closer to computer science others very ’biological’ in nature.)
** One day I hope to give readers a lot more detail.
*** Proc. Natl. Acad. Sci. July 26, 2005 vol. 102 no. 30 10413-10414.
Some recent articles in Code for life: