Sunday, 1 February 2009

Darwin Was Wrong?

So saith New Scientist. Unsurprisingly this is not that creationism is true and evolution false, rather that one of Darwin's big predictions about life is being superseded. The tree of life central to Darwin's thesis is inadequate to tell the whole story of life on earth, that a process of horizontal gene transfer not only plays a part on the unicellular level but in multicellular life as it is today. Evolution is happening, just in a more complicated way than was originally understood.

The web of life?
The aforementioned articles are a must-read in order to understand what the articles are saying. It's important to realise that ideas in science are never static and will be replaced as more evidence combined with different thinking come to light. Evolution in general is about as true as science can get, but the mechanisms behind the process are still being discovered. After all, life is a 4 billion year mystery to solve. This doesn't degrade the role of natural selection in the slightest, more it's a rethink on how mutation and variation come about.

As the article says, the tree structure of life still plays a role especially in the animal kingdom. We still have a more recent common ancestor with chimpanzees than we do with wolves, just as dogs have a more recent common ancestor with bears than with cats. Hybridisation breaks the tree analogy, as do ring species. As for viruses inserting genes horizontally, that again breaks the tree structure. To think that the tree structure would be a perfect fit for life as we know it is somewhat naïve. So where does this leave Darwin's initial relevation?

Like all science, ideas change or get superseded over time. Darwin's theory was always incomplete as there wasn't the amount of evidence that was around today. The core of his theory - natural selection still stands at the chief architect of the process, though the role of genetic drift does take away the role of natural selection somewhat. Likewise the tree structure is still there mostly (at least for animals and plants), but it's not a complete explanation. Copernicus was on the right path when he posited heliocentrism, but the truth was not yet discovered - that we are in the outer spiral arm of one of hundreds of billions of galaxies that are moving away from each other at staggering speeds.

The tree of life is not completely dead yet, though it's a little more intricate than first realised. Horizontal gene transfer is hardly revelatory, nor are the implications in the article. Was Darwin wrong? Well he wasn't entirely right, that's to be expected. Indeed if Darwin was able to make a theory that could take into account findings that happened over a century later, it would have been almost godlike if he had predicted it. There was no way Darwin could know, and it in noway diminishes his role in evolutionary theory that he did not know. The tree of life may have a few cobwebs connecting bits of branches, but for now the tree is still there.

The humanising of Charles Darwin
There needs to be a means to distinguish between evolutionary theory and Charles Darwin, the creationist use of the word Darwinism is unhelpful in that respect. It also puts Darwin on a pedestal, and the concept of evolution contingent on the works of Darwin - something in science which simply does not happen. Darwin's work also created a cult-like status among scientists and atheists too, the celebration of his works and insight has bordered on the fanatical at times. Evolution as an idea does not imply atheism, but it has led people to re-evaluate what it means to be human and what that means on a universal scale.

The theory at the time was revolutionary, that life has changed over time and even came about without the help of a deity had been proposed before Darwin (even by his own grandfather) but Darwin (and Wallace) proposed a theory that had a valid mechanism that could account for life on earth as it stands today. That all life was related was another great insight, something that has been validated through multiple lines of evidence. Horizontal Gene Transfer doesn't shift the interrelatedness but it does shift the relationship of that interrelatedness.

This is the year of Darwin, 12th of February makes the 200th anniversary of his birth, and 24th of November marks 150 years since the first publishing of The Origin Of Species. I have a copy of the book that I hope to read to coincide with it's initial publication date, but first I want to learn as much about the theory as possible so I can see where the ideas put forth by Darwin have been superseded. He's a scientific hero, just like Newton or Einstein. They are minds that have fundamentally changed how we view the universe, of course there is going to be some reverence among subsequent generations. What Darwin put forth was fantastic, but it is still the work of man. It wasn't even unique, without Darwin there was still Wallace who came up with the same idea. It was a marvellous insight into the world, but still a human insight after all. A great man who had a great theory, a secular and scientific hero - but not the deity Ray Comfort wishes him to be in the eyes of atheists.

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