The great biologist Lynn Margulis was born on this day in 1938. She did a whole bunch of stuff that I have to admit makes no sense to me. I’ve finally gotten to the point where I understand basic human biology. I know what a liver is and I know more or less what it does. That’s a big step up for me. But Margulis did work on a really basic level. For example, Wikipedia says that, “She showed that animals, plants, and fungi all originated from Protists.” What are Protists? They are a group of cells that have a nucleus and a membrane. What does that mean? I really don’t know. I kind of thought that all cells had nuclei and membranes. I though that was what made a cell a cell as opposed to a bunch of carbon molecules. But apparently what she did was very important. I suspect that if she had been a man, she would have been awarded a Nobel Prize. Just saying.
I know Margulis because of her work on the Gaia hypothesis. This is the idea that the earth itself acts as an organism. It was originally an idea of James Lovelock, which to him meant that the earth creates its own climate. There is certainly something to this. At one time, the atmosphere was mostly carbon-dioxide. As a result, plant life developed that could metabolize it and turn it into oxygen. Now we have animals that metabolize oxygen and so we have a cycle that has climatic consequences.
A misunderstanding of the Gaia hypothesis, that Lovelock in particular fell into, was thinking that because of the homeostasis of the earth’s system, that the climate couldn’t be upset. This is very clearly not the case. Just think of a human body. It is possible for it to get sick. It is possible for it to get a fever that causes brain damage or death. Just because a system does have stabilizing mechanisms, doesn’t mean that those don’t have a breaking point—especially when some external actor is pushing it in very unnatural ways.
I don’t actually know what work Margulis did regarding the Gaia hypothesis. But I suspect, that if I did, I wouldn’t understand it either.
Happy birthday Lynn Margulis!
Also noteworthy as the first wife of Carl Sagan.
Not all cells have nuclei — bacteria don’t for instance. They have genes but the DNA is just scattered through the cell materia.
@mike shupp – Thanks! I was hoping someone would set me straight. I really need to get a book on this kind of stuff. I was poisoned in middle school by being "taught" this stuff out of context.
I wanted to mention the Sagan marriage, but I couldn’t seem to fit it in. It is notable because they were both interested in the beginning of life.