A couple of weeks ago, I finished teaching The story of evolution: from theory to fact, as part of the Open Learning Programme in the School of Education, at Queen’s University, Belfast. I used to work as a schoolteacher but it’s quite a few years since I last taught in formal setting. I learned a couple of things about myself while I was teaching this course. First and foremost, I was reminded of how much I enjoy teaching! And that I’ve missed it. The second thing I was learned is that “biology”, in its many manifestations, is of primary importance to me. While writing has been a constant in my life, the natural world has forever been my core inspiration. I have a typical biologist’s facility for numbers (not so hot in other words!), which meant that following the science route in terms of my own education was often an intimidating slog. However, since I was very young and discovered the existence of the idea of evolution, I have always experienced it as thrilling in the breadth and depth of its narrative of life’s unity and diversity. Getting the chance to teach a course on it has only reinforced that sense of exhilaration.
I was clear that I didn’t want to teach a course arguing about the “theory” of evolution. As I emphasised to my class, evolution is only a “theory” in the same sense that there’s a “theory” that the earth orbits the sun. I wanted to teach a course the way I’d loved to have been taught about evolution myself. Not as the barely mentionable when I was at school, or the unquestioned doctrine when I was an undergraduate, but the story of how we, as human beings, came to understand and accept that evolution is a reality. A story of struggling human beings with vague intimations that gradually developed into this model that has such explanatory power. As Dobzhansky put it: “Nothing in Biology makes sense except in the light of evolution”. Evolutionary theory is a just that, a light we can shine to enable us to make sense of the world and our place in it.
I wanted to teach the historical story of evolutionary theory because the study of evolutionary biology is a historical science. So we swept grandly through two and a half millennia from Ancient Greece to the present day. I drew on my own decades of reading the work of individual scientists; and of reading about them. And, because I’ve only fairly recently completed my PhD, I was also able to incorporate the latest developments in evolutionary theory. After briskly passing through Ancient Greece and the Enlightenment, we were able to spend a bit of time with Darwin. Darwin’s own personal journey has been much told, of course, but the man’s life remains a fascinating reflection of the journey of evolutionary theory itself. How his personal revelation – backed by unremitting labour, the slow accumulation of fact after fact after fact, his fearful but convinced interpretation –started a revolution. We moved through the debates and disagreements of the late nineteenth and early twentieth century, until we reached the consensus of the Modern Synthesis of the 1940s. Which was swiftly discombobulated by the flow of information arising from the discoveries of molecular biology. That flow of information hasn’t stopped, but it is fascinating how epigenetics and plasticity theory are overturning the Central Dogma of molecular biology: that information flows outwards from the genes. In truth, a revised and more realistic version of Lamarckism – the idea that environmental effects on the body can be inherited – is gaining ground; but only with a fuller realisation and understanding of the complexity and responsiveness of the organism. The body and its development was a black box for the discoverers and explicators of DNA. We have opened that box. We are beginning to get a handle on it. It’s still dark in there but it’s definitely getting lighter.
The truth, as always, is rarely simple. As I quoted Orgel’s second rule recently (I love this. I can see myself continuing to quote it): Evolution is cleverer than you. Evolution – life – escapes our simplistic definitions, our search for grand unifying theories. It will not, actually, be kept in our boxes. Or our silos. It branches, twists, digresses – regresses – progresses only in the sense of what some have called the continuous dialectic between the internal and external environments. Life is responsive, flexible and dynamic. Maybe another word is creative? And our modern understanding of how evolution works through the interaction of genetics, environment and the responsiveness of the individual organism, continues to shine light on the beauty and diversity of the living world.
I was blessed with a great group of participants who really engaged with material and debated the issues with thoroughness, scepticism, passion and profound interest. I really enjoyed the discussions and the challenges of a diverse group of people united, as one put it, in the need to understand evolution for the twenty-first century. I would like them to thank them sincerely for being my “guinea pigs” in helping me develop this course which will – I hope – itself continue to evolve into the future.