Free Radicals - Michael Brooks [82]
These accolades didn’t come without a fight – a fight, in fact, that Margulis waged against many of the people who now acknowledge her brilliance. She is a textbook anarchist. She is, Dawkins says, ‘extremely obstinate … the kind of person who just knows she’s right and doesn’t listen to argument’. Engineer and inventor Daniel Hillis is more direct about the anarchy. To most biologists’ minds, he says, Margulis ‘didn’t follow the rules and pissed a lot of people off’.
But she had to. ‘Most of the science that gets done gets done within a rigid set of rules, where you know exactly who your peers are, and things get evaluated according to a very strict set of standards,’ says Hillis. ‘That works, when you’re not trying to change the structure … when you try to change the structure, that system doesn’t work very well.’ He is right. Everyone else who had tried to get this idea across played by the rules – and without success.
In 1883, the French botanist Andreas Schimper made an interesting observation. He saw that chloroplasts, the parts of plant cells that make energy from sunlight, divide in exactly the same way as cyanobacteria, which also make energy from sunlight. Perhaps, Schimper tentatively suggested, this was because green plants were the result of some kind of merger between other biological organisms.
Konstantin Mereschkowski, who lived and worked in Kazan, Russia, liked this idea. He explored it in his herbarium, where he kept more than 2,000 specimens of lichen. Many of Mereschkowski’s lichen were ‘symbiotic’ combinations of fungi and cyanobacteria. In symbiosis, two organisms benefit from the other’s presence. In some lichens, for example, the bacteria gain a water and mineral trap, and the fungus gains access to nitrogen that the bacteria can pull from the air. Around one-fifth of fungi are now known to live in such a symbiotic relationship.
In 1905, Mereschkowski proposed that biological complexity might have arisen from such arrangements being made permanent. If simpler organisms start to live symbiotically, would it be such a stretch to imagine them becoming biologically unified? Yes, was the reply from biologists – and yes it remained for more than sixty years. As the ideas of Darwinian evolution took a firm hold, it became established dogma that biological change happened through the slow evolution of one species into another. Anyone who suggested that it could happen through a union of two organisms had to be deluded.
No wonder, then, that Ivan Wallin gave up on his research. In the 1920s, Wallin, who was working at the University of Colorado medical school, suggested that the mitochondria that generate energy in every cell in your body are actually enslaved bacteria. He made the suggestion because, looking down his microscope, he couldn’t tell mitochondria and bacteria apart. After none of his nine papers on the subject were taken seriously, he gave up research and became a teacher and administrator. It was only when a true anarchist arrived on the scene that Mereschkowski and Wallin’s ideas found the champion they needed.
As with Stanley Prusiner’s prions, Lynn Margulis’s big idea was essentially one that other people had had before. In her case it was Mereschkowski and Wallin’s suggestion that the mechanics of life going on inside our bodies is the result of symbiotic relationships between bacteria and other organisms.
The idea is so hard for Darwin’s successors to accept because it denies that all the variation in nature results from random genetic mutations. According to the classic genetics-plus-natural selection camp of biologists – known as neo-Darwinists – environmental factors produce mutations in the genome that are passed on to the next generation. Some