Tuesday, October 17, 2006

I knew nature vs. nurture was too simplistic

I learned something new today!

I love it when that happens! Too often I think I know it all and even when I know I don't know it all, I might know a little something of it, which - of course - makes me think I know it all.

I found out there is a field of study that I have never even heard about. I read about it in Discover, one of my favorite magazines (I am all about making science accessible and this magazine does that). Anyway, the field is Epigenetics, which has nothing to do with Eugenics (a black mark in the history of science that you should at least be aware of).

You've all heard of "Genetics" (the study of genes and heredity) and the Human Genome Project, which sequenced the entire human genome. That project was expected in some quarters to be the panacea - we could now develop designer drugs, or designer babies - and instead left us (as new discoveries are often wont to do) with a whole new set of questions. Like "How is it that humans only have about 50% more genes than a roundworm?" and "Wow, do you suppose 'junk DNA' might actually do something?... 'cause there's an awful lot of it".

Anyone who has ever thought seriously about DNA, has at one point wondered "If every cell has all the information in it to create every protein imaginable, how does a liver cell know not to make a brain protein?" Well it turns out that the protein environment that the DNA is in (chromosomes are only 50% DNA) makes some protein's information accessible and others not so much or not at all. What has mostly been assumed up until this point, is that only the DNA is passed down from parent to child; that the protein environment is a slate wiped clean once an egg or sperm is created.

Here is a shocking bit of news from the field of Epigenetics (epi - 'upon, near to, in addition' Greek Origin), the protein environment that the DNA is in, is also inherited from our parents (which is logical once you think about it, we inherit chromosomes from our parents, not just DNA). Even more shocking, the epigenetics may last several generations. Daphnia water fleas when exposed to predators, grow defensive spines that are heritable for several generations.

The Discover story starts off describing that a well-studied genetic defect in mice (causes mice to be obese and susceptible to life threatening diseases) can be completely erased with nothing more than a change in the mother's diet. When you consider that the epigenetic environment can be altered by diet or by social circumstances (war, famine, stress, love, joy), you start to get that how you see yourself really matters. In case I lost you with that last train of thought... how you see yourself determines what you do, and if you think that what you do only affects you, you may be way off.

The article in November's issue is really great, I highly recommend shelling out the twenty bucks it costs to subscribe to Discover (see link in sidebar).

1 comment:

Anonymous said...

Thanks!! For you, your insight, your friendship with my son, and your wonderful article on epigenetics. The article was not unknown to me on a psychological level but was something I didn't think about every day. I, however, thanks to you, will be making some changes.
Take care, you are one of the special ones.
Leslie Berg