Tuesday, May 3, 2016

An Intimate History

When the kids were grown, I decided to go back to school and finish the degree I’d started 25 years before. A college-level Biology class was being offered in town, and though I hadn’t taken many science classes before, I signed up.

 I never realized that studying Biology would be a religious experience. Nor that the idea of DNA was as difficult to comprehend as the sound of one hand clapping. I could barely get my mind around the idea before it would vanish—a disappearing revelation.

 Now I learn (through the New Yorker) that there’s more to the stuff our selves are made of than just the double helix. Things that happen to us are recorded on a cellular level, permanently, on those little ladder things that bridge the strands of DNA.

 They are called histones, and modifications to them can change the activity of the gene without affecting the sequence. They are epi-genetic, over-genes, and they are the way a cell can record experience.

All this is discussed in a book by Siddhartha Mukherjee to be released this month, The Gene: An Intimate History. Mukherjee, a professor at Columbia University’s medical school, won the Pulitzer Prize in 2011 for The Emperor of All Maladies, a book about cancer.

So Epigenetics is the hot new field of study in the biological sciences, and what is already known raises some revolutionary questions as well as posing some evolutionary problems. One question is whether those cell memories can be inherited. This possibility seemed to be resolved back in the nineteenth century when Darwin’s theories pretty much got those of Jean-Baptiste Lamarck (giraffes got those long necks by trying harder) laughed out of Science. Now the possibility—albeit remote-- is there again, since whatever happens to us is recorded on a cellular level. The cells multiply with this amended information, and our genes are of course passed on to the next generation.

Identical twins, such as Mukherjee’s mother and her sister, can become a great deal different from each other over time because of epigenetic information. A lot of things had been recorded in my histones between the 1950s in Tennessee and the 1970s in California. I was, as “The Music Man” had it, a sadder but wiser girl. So when we say “Oh, he’s a different person now,” we are speaking a scientific truth at a very fundamental level.

“Genes form the thread of the web (jaal) Hindu philosophers described as being,” Mukherjee writes. “The detritus that adheres to it transforms every web into a singular being. An organism’s individuality, then, is suspended between genome and epigenome. We call the miracle of this suspension ‘fate.’ We call our responses to it ‘choice.’ We call one such variant of one such organism a ‘self.’”

 That paragraph alone might well have earned the Pulitzer Prize.