203 years ago today, Charles Darwin was born. Darwin’s most wonderful idea, evolution by natural selection, eventually became the organising principle around which the field of biology is built. But from a more self-absorbed perspective, that idea is also what first attracted me to biology.
In high school, I wanted to grow up to become either a filmmaker or an English professor. But I was also a giant nerd, and in Year 11 I won an award for biology, the prize for which was a book voucher. For the sake of the award ceremony I decided I should choose a book about biology–The Panda’s Thumb by Stephen Jay Gould. The cover featured a panda intensely inspecting its thumb, which resembled another intensely focused panda displaying another thumb, which was yet another panda, and inside were 35 essays on topics close to the paleontologist-writer’s heart: evolutionary theory, Darwin, the history of science, and the politics of human difference. Frankly, to my teenaged eyes it looked boring, but I read it anyway. I had long known the principles of natural selection, but in school the ideas seemed dry and cramped. My dinosaur phase had come and gone without me ever thinking too hard about the processes that turned the descendants of walking reptiles into flying birds. Gould’s reflections, on the other hand, gripped me with an intensity that I think is best encapsulated by the expression of the panda from the front cover. He (Gould, not the panda) made me think about adaptation and change in new ways. He used unforgettable stories from nature, like bacteria that sense magnetic fields, the pseudogenitalia of female hyenas, the mites that die before they are born, and of course, the panda’s ‘thumb’ that is really a modified wrist bone. He turned the bearded anonymity of Darwin into a tangible person, one that grappled with real data and put together his ideas as best he could. He picked apart those ideas with fire and grace. He drew me in to a world of scientific debate and I couldn’t get enough.
I quickly read every Gould essay I could get my hands on, and because I was spending so much time browsing the biology shelves of the public library, I started picking up other books on biology. One day, I came home with The Making of Memory: From Molecules to Mind by Steven Rose (fully illustrated). The book was not only about the neurobiology of memory, it was about what it meant to be a scientist. It opened with a kind of ‘day in the life’ of a neuroscientist and an extremely memorable description of a two-scientist production line, in which one person was responsible for cutting the heads off baby chicks, and the other scooped out the brains for analysis. As a vegetarian, and a snuggler of all things adorably fluffy, that book made me squeamish, but it also gave me the strange idea that I too could be a scientist, chipping away at our understanding of the world.
Factoid that connects the two books that made me a biologist: Rose was a Marxist. Gould was not, but was often accused of being a secret Marxist by his detractors.
But the book also made me sad. I thought science was out of reach for a book geek like myself. One night, at a gathering of restless teens, I told a friend about my new idea.
“I want to be a neurologist. But I can’t be, because I don’t think I could cut the heads off chicks all day.” My friend looked like she wanted to shake me.
“You could totally be a neurologist,” she insisted. “I want you to be one. You could employ me to deal with the chickens for you.”
Although that didn’t sound like a practical solution, the more I talked about my idea, the more confident I became. I asked my school’s vice principal if it was too late to drop my humanities electives and pick up chemistry. It was. He talked about how many months I’d missed, and how I would have to catch up by myself with the textbook. Then he told me that he knew I could do it.
So, fifteen years later, here I am, a soon-to-be-unemployed biologist. I lost interest in neurology at some point, but I never lost my love of Gould, and of Darwin, and their beautiful ideas. I tried, briefly, to become an evolutionary ecologist, before I realized I didn’t have enough maths training. Instead I find myself a specialist in the ways of the bakers’ yeast (brewers’ yeast, to its friends). Yeast are fungi, like mushrooms, but single-celled and not especially adorable. However, they do have their benefits as a study organism. The most important of those benefits, for my line of work, is that like every other living thing on earth, yeast are my relatives.
About a billion years ago, there was a free-living, single-celled organism not too dissimilar from a yeast, or a cell from my body, or one of the rat cancer cells in petri dishes that I will feed as soon as I have finished this post. That ancient organism had a nucleus, which is to say that a membrane separated its DNA from everything else inside the cell. That cell also carried a vital, energy-generating, pet bacterium (the mitochondrion). It also had a system for transporting things in and out of the cell in bubbles of membrane (the endomembrane system). At some point in its life cycle, it must have had a single, whip-like flagellum that flapped from its posterior end. This busy cell was the last common ancestor of both me and of the yeast I have just arranged onto a nutritious bed of jelly to be ready for an experiment next week.
Because we are related by heredity, many of the things I learn about those yeast cells will also be true of my own cells. I take advantage of this fact to study a human disease called antitrypsin deficiency using quickly dividing, cheap-to-grow, non-adorable yeast cells. When I make a discovery in yeast, I test whether it might also hold for mammalian cells by repeating the experiments in those rat cancer cells I should be tending. If my ideas are borne out by those experiments, then I turn them over to the medical scientists that study antitrypsin deficiency in the millions of humans that are afflicted by the disease worldwide.
Without an evolutionary framework, the way that I study antitrypsin deficiency wouldn’t make sense. It’s thanks to Darwin’s ideas that I became a biologist, but it’s also thanks to Darwin’s ideas that my work has value. So, please raise a glass of whatever you like to drink on a Sunday and wish a Happy Darwin Day to biologists, to all of humanity, and to our Opisthokont* cousins.
*Opisthokonta is a class of organisms that includes fungi and animals. Yeast and I are both opisthokonts because we are eukaryotes, but are more closely related to each other than to plants and our other, weirder, eukaryotic cousins.