Gene, gene: the meadow is green. And where are you when I need to blame you for something?

In "Scientists and philosophers find that the gene has a multitude of meanings," (New York Times, November 10, 2008), Natalie Angier made a useful point:

Scientists have learned that the canonical “genes” account for an embarrassingly tiny part of the human genome: maybe 1 percent of the three billion paired subunits of DNA that are stuffed into nearly every cell of the body qualify as indisputable protein codes. Scientists are also learning that many of the gene-free regions of our DNA are far more loquacious than previously believed, far more willing to express themselves in ways that have nothing to do with protein manufacture.

Indeed.

Much of the public still thinks that there is a "gay gene" or a "swinger gene" or a "fat gene."

As if. As if some unhappy friend's tomcat boyfriend has a "swinger gene."

A message to any women who are reading this: Look, if your life is a mess, it's you, basically, it is not your genes. Forget all that garbage.

If your boyfriend is a tomcat, why are you with him anyway? If you know you deserve better, it must be true. Otherwise, how would you have known?

Perhaps you must live a while without a boyfriend, but ... at least you won't bother wondering who he is with. Maybe he's dating the Devil's daughter. So? If you hear screaming in the night, shut the window and call the police. Don't get involved.

If you have reached the end of your rope, go here for help. If you haven't reached the end of your rope, there are other places you can try, of course, but we deal with the worst cases here, so you may as well go here first.

Find out why there is an intelligent design controversy:

Remember - one gene codes for one protein? Also. you ARE your genes? And all that?

Good. Now exercise your brain by forgetting all that.

Here Emma Young at New Scientist (09 July 2008) brings us up to date with a more plausible story:

No one is arguing that Lamarck got everything right, but over the past decade it has become increasingly clear that environmental factors, such as diet or stress, can have biological consequences that are transmitted to offspring without a single change to gene sequences taking place. In fact, some biologists are already starting to consider this process as routine. However, fully accepting the idea, provocatively dubbed the "new Lamarckism", would mean a radical rewrite of modern evolutionary theory. Not surprisingly, there are some who see that as heresy. "It means the demise of the selfish-gene theory," says Eva Jablonka at Tel Aviv University, Israel. "The whole discourse about heredity and evolution will change" (see " Rewriting Darwin and Dawkins?").

The demise of selfish gene theory is long overdue, of course.

I am a bit queasy about at least one aspect of this New Scientist article: An attempt to blame modern obesity rates on ancestral diets. Modern obesity is mainly due to lack of exercise. If the most exercise you ever get is moving the cursor around, you have one impressive index finger, second joint upward, but ... that's like about .2 percent of fitness.


Find out why there is an intelligent design controversy:

Can a gene really make you fat?

Many people have worried a lot about genetic determinism—the belief that there are master genes that control our behaviour — crime, obesity, sexuality, honesty ...

There are two separate worries here: First, is it true? If so, free will does not really exist.

More practically, what if large numbers of people believe it is true, even if it isn’t? Then those people will act as if they, and we, have no free will. They will have a bad effect on society even if they are wrong.

Fortunately, recent developments in genetics are making clear that this sort of “reductionism” — reducing everything to a single factor — is nonsense. There are no single genes that control human behaviour. Popular literature often does not catch up with new science developments very quickly, so it might be helpful to summarize a couple of key points here:

Not very long ago, as MIT science historian Evelyn Fox Keller notes in The Century of the Gene, biologists thought that if we could read the human genome, it would explain everything there was to know about a person. As Francis Crick put in in 1957, “DNA makes RNA, RNA makes protein, and proteins make us.” This was the “central dogma” of biology for nearly fifty years.

Quoting another scientist from about 15 years ago, Keller says,

Spelling out his ‘Vision of the Grail,’ Walter Gilbert wrote, “Three billion bases of sequence can be put on a single compact disc (CD), and one will be able to pull a CD out of one’s pocket and say, ‘Here is a human being; it’s me!’"

Then she adds, “Today, almost no one would make such a provocative claim.”

So why would almost no one make such a claim today? Both genes and organisms have turned out to be much more complex than anyone imagined. As Keller notes, “Indeed, the functional gene may have no fixity at all: its existence is both transitory and contingent, depending critically on the functional dynamics of the entire organism.”

As a recent article in the Guardian Education supplement explained, most genes do not do only one job:

Rather than having a single major function, most genes, like roads, probably play a small part in lots of tasks within the cell. By dissecting biology into its genetic atoms, reductionism failed to account for these multitasking genes. So the starting point for systems biologists isn't the gene but rather a mathematical model of the entire cell. Instead of focusing on key control points, systems biologists look at the system properties of the entire network. In this new vision of biology, genes aren't discrete nuggets of genetic information but more diffuse entities whose functional reality may be spread across hundreds of interacting DNA segments.

Put simply, if you have a tendency toward inactivity that causes you to gain weight, there isn’t a “gene” that makes you fat. Your tendency is likely the result of a system with hundreds of components, interacting with other systems with hundreds of components. The bad news is that it is more difficult to understand than a simple system. The good news is that it is much easier to influence than a simple system, because you can influence many different components. So biology is not destiny after all.

Of course, we can expect years of headlines about the “shoplifting gene,” the “compulsive spending” gene and so forth. Promising ideas die hard. That little word “gene” promises us absolution without ever having to say we’re sorry—or even admit that we did something bad.

To find out more about my book about the intelligent design controversy, go to By Design or by Chance?