viernes, 5 de junio de 2009
Darwin, evolution, and the genesis of intelligent design
Charles Darwin has a lot to answer for. He saw the world with new eyes, fundamentally changed our understanding of nature, and upset a lot of people in the process. 200 years after his birth, Darwin’s work underpins modern biology. His findings still challenge, stimulate and—amazingly—offend people the world over. And his discoveries continue to teach us a lesson we are only now beginning to appreciate fully—that life is plastic; that it can change and adapt, and can therefore be manipulated and controlled.
It’s this last point I want to write about on the 200th anniversary of Darwin’s birth. Because as well as possibly marking another critical step in humanity’s history, it also contains a delicious irony—but more on that in a moment…
Manipulating living organisms isn’t new—people have been doing it through selective breeding for thousands of years. But until Darwin’s time, it wasn’t clear what the underlying principles were, and how far selective breeding could be pushed.
Darwin’s genius was that he recognized that plants and animals have an ability to adapt to their environment and to pass these adaptations on to subsequent generations, and that over time these adaptations through natural selection can lead to profound changes.
Yet while Darwin recognized that living things are constantly changing and adapting, he wasn’t able to elucidate the mechanisms underlying this adaptability. It was only when Crick/Watson/Franklin discovered the structure of DNA that things began to get really interesting. The combined knowledge that living things can change, and that the key to that change is a sequence of molecules embedded in all living cells, was powerfully transformative.
As science and technology progressed through the 20th century, this understanding led to genetic engineering—extracting sequences of DNA from one organism and transplanting them into another, to create plants and animals with new features and abilities. But this was—and still is—crude stuff. Granted, modern genetic modification is pretty sophisticated and has produced some important products (along with plenty of vocal opposition). But in absolute terms, it hasn’t progressed much beyond the equivalent of crafting fine jewelry while wearing boxing gloves.
All this is changing though. And it’s changing because of two developments that are transforming how scientists manipulate the genetic code that determines the form and function of all living things.
The first development is DNA sequencing. The ability to read the sequence of base-pairs that make up DNA has been around for a while, but it’s getting faster and more accurate by the day. The first “working draft” of the human genome took 13 years to compile, and was completed in 2001. Six years later, the first sequencing of an individual’s genome for under $1 million was completed—and it took a mere 2 months. And currently, there are companies speculating that by the year 2013, they will be able to read a person’s complete DNA sequence in the time it takes to boil an egg—three minutes!
This in itself is impressive. But it’s not the most important aspect of DNA sequencing. What is most significant is the transformation of biological information—information stored and used in the physical/biological world—to digital information. Because as soon as the full genetic information of an organism is in the digital world, it can be manipulated, re-written, and even debugged, with an ease and speed that would be impossible in the physical world. What is more, you can have 10, 100, 1000+ people working on the same “code” in parallel, working out how to change it to achieve specific ends.
But this development would be a mere intellectual diversion if it wasn’t for something else: the ability to construct DNA sequences, and splice them back into living organisms. The cost and ease with which DNA sequences can be synthesized is crashing. Have a sequence of base pairs on your computer you want as actual strands of DNA? Simply email it off to one of many companies, pay a few hundred dollars, and receive the physical molecules in the mail a few days later—what could be simpler?
This synthesis step completes the loop—it enables scientists to upload genetic information into the digital world, change it, then download it back into a physical organism.
Just as Darwin’s work transformed how we perceive biology, this new digital biology will transform what we do with it.
Think about it. We are on the brink of being able to transfer the instruction set of something that’s living into computer code, change that instruction set—even write a completely new instruction set—then transfer it back into something that’s alive. In means that the metaphorical boxing gloves are off as far as genetic engineering goes. It means that what we can achieve will be limited only by our imagination and understanding of how biology works. It means that, at some point soon, we will be able to design and create from scratch new life.
To get a sense of the scale of this development, consider for a moment how digital special effects have transformed movies—where the physically improbable can be made to look real. Now imagine being able to do this in real life—not just in a two-dimensional facsimile on a movie screen. There may be a dash of hyperbole in the analogy—but not a whole lot I suspect.
And this is where we get to that rather delicious irony I mentioned earlier.
One of the big objections to a Darwinian world-view currently in vogue is the idea of irreducible complexity. The argument goes something like this: Certain bits of biology are so complex, that they couldn’t possibly have evolved. Therefore they must have been intentionally designed by an intelligent being. Ergo, there must be a creator behind life as we know it, and evolution is simply an illusion.
Ignoring the fact that this argument sounds more like something out of a Douglas Adams novel than an inquiring mind, this line of reasoning leads to the theory of Intelligent Design—the idea that some parts of biology at least must have been designed rather than being the product of evolution.
The irony of course is that scientists are now close to being able to intelligently design biological systems and living organisms. But in this case, the designers are human, not deities or some super-intelligent race of beings.
This, naturally begs the question: If a thousand years from now (after scientists have designed the most intricate of organisms, society has subsequently collapsed and reformed, and humanity’s “institutional memory” has become a little cloudy) future scientists look closely at the organisms that surround them, how will they be able to distinguish between what has evolved naturally, and what has been intentionally designed?
A tricky question.
But here’s one plausible answer: Scientists, being scientists, are bound to insert their own hallmark into new designer bugs—a “designed by X” sequence that will allow anyone in the know to distinguish between what is natural, and what is not. We’ve already seen this with the first fully synthesized genome of a bacterium—where Craig Venter’s team inserted watermark DNA sequences. The sequence of amino acids expressed by these sequences spelled out “CRAIGVENTER” amongst other things—leaving you in no doubt whose brains were behind the bug.
OK, so there will need to be some fancy biology to prevent future watermarks being corrupted through mutations. But it’s a pretty safe bet that future intelligently designed organisms will carry some form of identity tag, care of their makers.
But if this is the case it makes you wonder whether, if the Intelligence Design advocates are right, we all have a designer tag buried deep within our DNA already—a sort of “GOD WAS HERE” watermark. Perhaps this is what the ID folks should be concentrating on, rather than the intellectually barren idea of irreducible complexity.
Perhaps they already are!
Back to reality though. Shifting biology between the physical world and the digital domain will likely lead to changes as profound and transformative as those instigated by Darwin 150 years ago. If the past is anything to go by, we could be in for an exciting ride. Molecular-level control over genetic information raises as many concerns and questions as it does opportunities. If we learn (as a society) how to use our new-found knowledge and abilities wisely, this is clearly a science and technology that could make many peoples’ lives significantly better. On the other hand, it will challenge some people’s notions of what life is, and the boundaries within which humans should operate.
Either way, this “synthetic biology” marks a turning point between natural selection-driven biology, and engineered biology—it is, quite legitimately, the genesis of intelligent design!
What better way to mark the bicentenary of the man who thought the unthinkable, and changed the world.
February 11, 2009
http://2020science.org/2009/02/11/darwin-evolution-and-the-genesis-of-intelligent-design/#ixzz0HaKgBsPJ&D
Darwin, evolution, and the genesis of intelligent design
2009-06-05T21:19:00+02:00
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