Thursday, 28 February 2013

60 Years Ago on This Day: The DNA Structure's Discovery

On the 28 February 1953, James Watson and Francis Crick pieced together the first model of a DNA molecule – the three-dimensional double helix. A brilliant insight and also an interesting story that lifts the lid on the less appealing side of a scientist’s life – the race to beat your fellow scientists to the Nobel prize even at the cost of 'spying' (to use Watson's own word) on competing scientists. There is the notorious episode in which Watson peeked at Rosalind Franklin's X-Ray Crystallography image of DNA without her knowledge and consent. The fact that she died a few years later, apparently without knowing what massive contribution she had made to the the DNA structure's discovery, makes for a rather sad story.

It was perhaps the unfairness of this episode that prompted some commentators to ask quite how much Crick and Watson’s breakthrough owed to other scientists. Watson himself acknowledged without hesitation that they could not have succeeded without Franklin's involuntary help. There was one other contemporary scientist who supplied an important piece of the puzzle Crick and Watson so brilliantly solved. In 1950, Erwin Chargaff discovered a remarkable symmetry in the amount of nucleotides -  regardless of the species the DNA came from, Adenine occurs in equal amounts to Thymine, and Cytosine occurs in equal amounts to Guanine. Based on this, Crick and Watson figured out how the nucleotides were paired up in the DNA molecule.

Going further back in time, the first clues as to the structure of DNA was provided by Phoebus Levene in 1919. He revealed for the first time the polynucleotide structure of DNA. He also discovered ribose and deoxyribose as well as identifying sugars and phosphates as chemical constituents of the DNA molecule.

As for the function of DNA, this was well known by the time Crick and Watson elicited the structure of the molecule, although it wasn't clear how that function was performed. It was as early as 1869 when Johann Friedrich Miescher stumbled over DNA  (he called it “nuclein”), while studying the proteins in white blood cells. Amazingly, he even had the hunch that nuclein was the agent of heredity – an idea that was so far ahead its time that it didn't attract much notice. Decades later, in 1904 Thomas Hunt Morgan proved the correlation between chromosomes and hereditary traits, famously experimenting on fruit flies.  And in 1944 Oswald Avery proved that DNA was the active agent in heredity.

Crick and Watson’s breakthrough was indeed made possible by the work of many other scientists (everything considered, probably many more then the ones mentioned above). It is usually like that - hardly any scientific theory comes out of the blue, especially in our day and age when human knowledge is becoming more and more complex. The fact remains that the two scientists were the first to discover the structure of the DNA molecule and they deserve their prize. Had Rosalind Franklin lived, she would have certainly shared in the 1962 Nobel prize, as did her colleague at King's College London, Maurice Wilkins. I remember a happy note in Channel 4's "DNA - The Story of Live": Those who knew Franklin well say that what she wanted most was for her work to contribute to scientific advancement. That it most certainly did.

Wednesday, 20 February 2013

The Wisdom of Crowds

I’ve finally got round to reading James Surowiecky's “The Wisdom of  Crowds”. It's been sitting on a shelf for some years and every time I had a glimpse of the title I wondered if the book was going to highlight any positive sides to group-think.

Well, far from it. The author does argue that crowds are better at making decisions than individuals, but independent thinking by each of its members is vitally  important to the quality of the decisions. The independent judgements of the members are then aggregated or averaged into a crowd decision. The interesting point Surowiecky makes is that decisions made following this process will often be at least as good as – and sometimes better than – the decision of the cleverest members of the crowds. This is apparently true even when these individual members are experts in the relevant field!
The other success factor in this collective decision-making process is diversity. Therefore size matters – the bigger the crowd, the more diverse it will be.

It's good news for democracies, as well as an argument in favour of freethinking. It's good news for non-freethinkers too – apparently “you can be biassed and irrational, but as long as you're independent [in making your decision], you won't make the group any dumber”. The extreme positions held by various members of the group will cancel each other out. I do find it ever so reassuring, that any lapses in my freethinking will not cause any disasters. Perhaps a corollary of this book is that I should always abstain from proselytizing, so that I don't spoil the independent thinking of others :-)

Thursday, 14 February 2013

Is “I don't know” the first step to wisdom?

Heinrich Zimmer's “The King and the Corpse” is one of my favourite books. Although the English version is not the best written one, those who get past the clumsiness of the language will be well rewarded by rich meanings and beautiful metaphors.

The story is about a king whose judgement and wisdom are put to the test – he is given the grim task of finding the corpse of a hanged man on its execution ground and bring it into the magic circle of a sorcerer. Along the way, the corpse tells him a story, at the end of which the king has to answer a question. The rights and wrongs in the story are so tangled, the opposing sides of the argument so closely matched, that – if the king truly understands the complexity of situation – he will not be able to call it. The only way he can possibly come up with an answer is by deferring to custom, tradition, and borrowed “wisdom”. This is exactly what he does and, as soon as he answers the riddle, the corpse flies off his shoulder, back to the tree where it had been hanged.

There are twenty-four riddles in all. Twenty-three times the king is confident he has the answer, and twenty-three times the corpse returns to its tree. Until finally the king is presented with a riddle he cannot solve. As he goes on puzzling over it in silence, the corpse is finally satisfied that the king has reached the point of wisdom. Not only that the king is then able to complete his task, but he is also given the all-important knowledge that will enable him to defeat the evil sorcerer and become a truly great king.

The morale of this story appears to be that the king is wiser in his silence than in his replies. That admitting ignorance is better than giving simplistic answers based on prejudice.

Being realistic about the limitations of human knowledge safeguards our ability to better that knowledge. Every scientific theory is valid till proven wrong. Staying open to factual evidence and being ready to reconsider ideas that we have once held as truths is where the strength of science lays. Resilience through flexibility: the fact that bricks are replaceable makes the edifice as a whole long-lasting and stronger.

Tuesday, 5 February 2013

A freethinker, yes. An atheist? Not necessarily

Freethinkers are people who apply their own individual judgement in deciding what is true and strive to build their opinions on fact and knowledge, independently of authority, prejudice, group think and dogma.

Freethinkers are usually assumed to be atheist. I think this is not quite in line with the definition above. Since we don't really know how this universe came about, the existence of some creative power cannot be proven or disproven. Therefore wouldn't it make more sense that freethinkers should be assumed by default to be agnostics?

As far as I am concerned, keeping the question open does not in any way stop me from experiencing the sense of awe and wander at the miracle this world is.
This universe – billions of galaxies, stars dying, stars being born, atoms being forged – isn’t it just mind-blowing? Life on earth – how inanimate matter one day turned into a living thing – that is a miracle. We might one day figure out how it could have happened. That will not make it any less of a wonder. Each of us is a miracle of atomic engineering. We have billions of years of evolution behind us, enabling us to feel at home on this planet. If these are not blessings then I don't know what is. Even with no guarantees about our future, which a father-figure sort of God might grant, there is a lot to be grateful for.

However abstract and un-knowable the force that made this world possible, I think it could still be celebrated and – why not? – even worshipped.
In the same way that an optimistic or pessimistic outlook colours one's view of reality, we can also see the world and the universe as sacred or mundane. The question is: which one do you choose?