Adam, Pluto, and Gene

First, let me acknowledge a cool new blog that a good friend of mine has started, called “Psychohistory.”

The blog, written by Adam Nash, a Director of Product Management at eBay, does a better job of explaining the title than can I. But suffice it to say that Adam is one of the brightest and most critical thinkers I know, and I’m quite sure that his thoughts will be both interesting and abundantly insightful.

Speaking of Adam’s blog, I’m reminded of a recent pop-science discussion topic from the past week — the downgrading of Pluto from planet to non-planet. If you read any typical news outlet, you’ve probably heard some buzz about this little scientific determination, and you probably have the same reaction that Adam and a lot of others have had — how can such a basic fact of high-school science be overturned so quickly and easily that virtually every general science text is immediately outdated?

It seems crazy that something that has been presented as basic scientific fact for so long is proven otherwise. But, believe it or not, this sort of thing happens all the time. And more times than not, it doesn’t make the front page of any newspaper, and it’s not until our kids (well, other people’s kids :) ), come home from school and recite some scientific truth that completely contradicts what we learned so many years back in high school.

As an example, here’s another piece of conventional scientific wisdom that may be changing…

A friend of mine pointed out a short article in a recent issue of The Economist, called “A Curious Tail.”

(The link above requires a subscription…but here’s a related story from the BBC and another from The Scientist).

The article discusses a recent finding by some researchers at Inserm, a health-research institute in France, regarding the ability to transfer inherted traits through mechanisms other than genes/DNA.

As you might recall from high school biology, the basic unit of inheritance is a gene, which is piece of DNA — the master copy of the genetic code. In classical genetics, it was believed (and most of us have been taught) that every offspring is endowed with two sets of genes (two copies of DNA), one from the mother and the other from the father. And all of our inherited traits come from just these two sets of genes. In other words, the two sets of DNA that we inherit from our parents are the sole determiner of our genetic fate. Further, we’ve been taught that DNA follows a two-step approach to passing on its genes. First, it creates sub-copies of itself in the form of RNA. This RNA then creates the proteins that build life.

The theory holds that all hereditary information is stored in the DNA, and only that information may be replicated and therefore inherited. But the experiments above indicate that this basic tenet of biology may not hold — that RNA may have “memory” and replicate traits that were held by previous generations of genes, but not by the specific set of genes most recently inherited.

This means that we may inherit traits of our parents (and perhaps even grandparents?) that weren’t necessarily passed on to us through our genes!

I wonder how many other basic tenets of scientific fact have changed since I first learned them? I guess I’ll have to wait until I have kids of my own in high school to find out…