Wednesday 26 January 2000

Scientific American

Pic of the day: "I read the January issue of Scientific American..."

Life is hard and then you evolve

All things are connected. Sometimes it seems to me that the best laid plans of mice and men are but details in a master plan, cells in a larger body of consciousness so immense as to be unfathomable, the way a single cell even in your brain cannot comprehend the totality of your life.

Today, for instance, I was planning to write about junk DNA (finally). I chose the working title "Life is hard and then you evolve" before breakfast. Then I walked to the bus. And all around me I heard these soft crackling, tingling sounds from the snow that fell from trees. It had been hanging there for days. Now the air was milder and that must have caused the change. The morning was light and clear, only a few feather-like clouds, and yet mild air had arrived in the deep of winter.

Then on the bus I read the January issue of Scientific American with an article on the "snowball Earth" event, which I have mentioned in passing before. Basically Earth froze completely over, including the oceans, and then melted due to a buildup of CO2. Temperature rose from -50 degrees Celsius to +50 degrees Celsius. (50 degrees C is half way from the freezing point of water (0) to the boiling point (100). Pretty harsh.)

Then as we approached Kristiansand city, the road was almost blocked by lorries. It turns out that something like 10 000 lorries all over Norway are out blocking industrial sites, warehouses and docks, in an illegal protest against the high prices on diesel. Norway has one of the worlds highest prices on petrol products, thanks to our high carbon tax. Nominally this is an attempt to curb greenhouse gas emissions, but so far this has not happened, and also it is incompatible with the decision of our Storting (parliament) to okay the building of two freaking huge gas power plants on the west coast, that will skyrocket our contribution of greenhouse gases.

Greenhouse effect, greenhouse effect, greenhouse effect.

***

It's not enough that we get junk e-mail in our inbox, and junk papermail in our mailbox. No, we even get junk DNA at the very hour of conception. The human genome researchers have found that a large part of our chromosomes are actually meaningless genebabble. Disconnected and partly dissolved duplicates of other genes. Long repeats of short meaningless codes. And even "fossil" retrovirus who have been lucky enough to splice themselves into a stem cell in our ancestors. Some of these are recent enough to be similar to modern retrovirus, but others are almost dissolved into random mutations during millions of years. At least that is how it seems.

But there is still something strange here. And it ties in with the "snowball Earth" theory. You see, shortly after the the planet went back to a more hospitable climate, there suddenly showed up a lot of new life forms. Until then, there had been only single-celled and simple multi-celled organisms. Now suddenly the progenitors of all main groups of current animals showed up, already differentiated. In addition, there were some strikingly different animals who later went extinct.

This seeming act of unbridled creation followed on the heels of the worst disaster our planet experienced after life showed up. A disaster that must have wiped out nearly all life on Earth.

We see this pattern later, though at smaller scales, as there was never again such a terrible event as the Snowball and the heat that eventually thawed it. There were climate changes, and the occasional asteroid impact, destroying much of our planet's ecosystems. And then, shortly afterwards, an explosion of new life forms. Do you already guess what I am pondering?

***

I find it suspicious that we carry around lots of useless DNA, but then when things really get tough, there is suddenly a lot of useful mutations all at once. May there be some kind of experimental lab in the unused part of our DNA, from which life can dredge up new ideas when needed? I can't see how any such mechanism would remain undetected. Then again, when I was a kid we did barely know how the genes worked at all. There may still be surprises in those little nanomachines.

For instance, we are supposedly close relatives of the chimpanzee and the bonobo ape. But we have a different number of chromosomes than they. And it is not just that one chromosome has broken in two or been welded to another ... the missing ape chromosome is spread out over several of ours. How would that suddenly happen? Things like that don't happen today. Even repeating one tiny chromosome in three copies instead of two leads to the severe dysfunctions known as Down's Syndrome. Breaking up a whole chromosome pair (not one chromosome, two at a time, and the same two!) and redistributing the genes ... well, it is an almost incredible task. If this was routine, there would be any number of different chromosome counts in each species. Are there certain events that triggers a complete genetic restructuring? If so, what? Will we ever know? Will we eventually be able to unleash it and jump to a new evolutionary level in the course of a generation?

Or will this incidentally happen if we fly off to colonize new star systems? Settling in a brand new environment where all ecological niches are up for grabs, and where conditions are extreme. It looks strikingly similar to the situation after Snowball Earth. If history were to repeat itself, mankind might branch into species as different from each other as spiders are from whales. I'm not sure if that would be a good thing ... But boy would it make for great science fiction!

***

And since I'm never going to the stars, science fiction is all I have to offer today. Tomorrow, if any, will probably bring something entirely different. Watch this cyberspace!


Yesterday <-- This month --> Tomorrow?
One year ago

Visit the Diary Farm for the older diaries I've put out to pasture.


I welcome e-mail: itlandm@netcom.no
Back to my home page.