Overweening Generalist

Monday, July 18, 2011

Epigenetics: the Revenge of Lamarck!

[If you're a non-biologist and you know Lamarck's name it seems likely that you think of his idea that giraffes have elongated necks because they needed to stretch them to get to the food above, and the ones that stretched the most sent their stretched necks on to their offspring, and eventually the giraffes with the longest necks got the most food, most progeny, longer necks, etc...]

Probably the most popular metaphor for the human genome - or any living thing's genome - is the "blueprint." The blueprint was devised by some architect and is a map that will determine how a structure will be built, presumably down to the last detail. It's neat, sleek, elegant, intellectual and, depending on how you unpack it personally, possibly depressingly deterministic.

Another metaphor I noted, after the race between Craig Venter and company and the government-backed NIH to sequence the human genome pretty much ended in a dead heat around June of 2000, it was written more than a few times that, yes, we have sequenced three billion base pairs, but now we have a brand new Steinway...but we don't know how to play piano yet! Much work was to be done to find out how/why/when genes are expressed, how they might combine, how some are "turned off" and others "turned on," and, if we learn this - how to play "the piano" (possibly the Hammerklavier Sonata?) - we might find out how to cure cancer, prevent genetically inherited diseases, and possibly prolong human life and delay senescence.

All along a slew of researchers were busy studying individual genes and trying to figure out why, even in monozygotic (formerly known as "identical") twins, the two people could be so vastly different by age 20. 

Jean-Baptiste Lamarck, whose theory of acquired characteristics had been relegated to the dustbin of science, was all the while looming over this research: could something other than the digital inheritance of mom's and dad's genes - and possibly a random mutation or two, as allowed by neo-Darwinism - explain all the odd disparities? It turns out that the study of the organic molecules that coat genes on the DNA double helix regulate their expression. And of course RNA is involved in a very big way, probably bigger than you were taught in high school. RNA is not simply the messenger-boy anymore, oh no. The mechanisms of epigenetics seem byzantine in complexity, but a wonderful new book makes it understandable to a dummkopf  like myself.

(Here's Lamarck, whose ideas were left for dead, but who rose in the late 20th/early 21st century to haunt us with complexity and wonder):

I just finished a fascinating book called Epigenetics: The Ultimate Mystery of Inheritance, by Richard C. Francis, a Ph.D in neurobiology and behavior from Stony Brook who did post-doc work at Stanford and Berkeley. It arrived earlier this year and is, as far as I can tell, the first book on epigenetics written for the intelligent layperson. 

What's odd is that, for some reason, I didn't see Lamarck's name once in the book. I wonder why? Maybe I'll write Francis and ask. He's a freelance science writer now, and a good one.

Many others who have reviewed Francis's book have made the Lamarck connection, though...The story of the triumph of neo-Darwinism and the decline of Lamarckism is filled with political intrigue (see Paul Kammerer's downfall, and polymathic Arthur Koestler's The Case of the Midwife Toad, for the inklings of a true mystery, and I know full well the delicious irony of linking here to a creationist's writing!), which I will not go into now. But it seems safe to say that both Darwin and Lamarck were "right" and their theories are so advanced now that they wouldn't recognize the intricacies of depth they have engendered.

The most beautiful thing about Francis's book, to me, was the very real "light at the end of the tunnel" promise of epigenetics as the way to find a cure for cancer. 

The most disturbing thing about the book is that your life may have been altered forever by mom's stress levels while you were in the womb. This new approach to genetics eerily explains how a famine in the 1940s still affects the physiology of people born recently. It places a tremendous burden on our responsibilities to optimize our environments, and not simply from toxins: from stress-inducing environments too, which cause our DNA's expression to alter even when we are middle-aged. 

In addition, we can inherit from our grandfathers, not just our fathers. Epigenetics has a rather fat role to play in explaining the obesity epidemic. The implications of this study - in which DNA no longer plays the role of Executive - are astonishing. Here's Francis:

"Epigenetics is the study of how these long-lasting, gene-regulating attachments are emplaced and removed. Sometimes epigenetic attachments and detachments occur more or less at random, like mutations. Often though, epigenetic changes occur in response to our environment, the food we eat, the pollutants to which we are exposed, even our social interactions. Epigenetic processes occur at the interface of our environment and our genes." - from the Preface

The complexity found in epigenetic research and its implications staggers me, and this book arrives just as I felt like I was finally getting a decent handle on the 23 chromosomes and what they do, which was already abstruse for me. The old idea of "OGOD," or "one gene, one disease," has gone the way of phlogiston or the luminiferous ether long ago, to say the least...(With some well-known exceptions, but it seems that something like the clear-cut genetic understanding behind, say, Huntington's Chorea is fairly rare. The epigenetic basis for most diseases are fuzzy.)

It seems crystalline at this point that, a detailed working-out of the dynamics of epigenetics will go a long way towards the human species learning to "play that piano" well. (How about the Goldberg Variations? That should cure cancer, at the very least! One would hope...)

I think we underestimate the value of writers who so thoroughly understand dizzyingly complex scientific ideas that they can produce a book about them for the intelligent lay public and make the ideas seem far less opaque. Richard C. Francis has accomplished this, and kudos to him! May many people read this book! There's even some good stuff for baseball fans, even if it involves steroids, Mark McGwire, Jose Canseco, and epigenetics. (But why no mention of Lamarck?)


Cleveland Okie (Tom Jackson) said...

I never heard of this book before, so I'm grateful that you took the time to explain it, and explain why I should read it. But I'm still going to read "How The Hippies Saved Physics" first.

Loved the reference to the Goldberg Variations. Have you read "The Gold Bug Variations" by Richard Powers?

michael said...

I'm still waiting with baited breath (I just had anchovies on my pizza) to read the book on Sarfatti, Sirag, RAW, Herbert, et.al.

I have not read Powers's book.

There is quite a lot I have not read.