Debunking myths on genetics and DNA

Saturday, May 10, 2014

Sex, Genes, and Rock 'N Roll: Dr. Rob Brooks talks about how evolution has shaped the modern world

My guest today is an evolutionary biologist "who thinks about sex for a living": his job consists of exploring "the evolutionary and ecological consequences of sexual reproduction." Dr. Rob Brooks, a professor at the University of New South Wales, in Sydney, Australia, studies how evolution shapes many aspects of our life, like mate choice, the costs of being attractive, the reason animals age, and the links between sex, diet, obesity and death.

I just finished reading Dr. Brooks' book Sex, Genes & Rock 'n' Roll: How Evolution Has Shaped the Modern World, a fascinating journey into human habits and cultures seen under an evolutionary perspective, and I thoroughly enjoyed it. I confess it also left me pondering with some questions, and that's why I am so thrilled to have Dr. Brooks as a guest today on CHIMERAS!

EEG: Some of the research interests listed on your UNSW page are: "the evolution of mate choice, the costs of being attractive, sexual conflict, the reason animals age and the links between sex, diet, obesity and death." Besides publishing important papers, you turned these topics into a beautiful book that, without ever getting technical, describes who and what we are in evolutionary terms, weaving in genetics and animal studies. When and how did you get the idea to write Sex, Genes and Rock n' Roll?

RB: I’ve long wanted to write popular science books about evolution that both entertain and educate people who don’t get to think about evolution and at the same time to present new ideas for how my field of research might help us understand who we are. I especially wanted to demolish this reflexive habit we have of seeing things as either cultural or biological in origin. It’s an obstacle that prevents the biological and social sciences from learning from one another. So in early 2009, I was approached by Stephen Pincock, then a publisher at NewSouth, because he had heard about my research and wanted to commission some science books. He helped me get over that initial hurdle of conceiving the book and getting a contract to write it. It was very exciting, because without his nudge I might never have started writing.

EEG: Your book touches many issues in our society: obesity, excessive consumption, teenage excess, disruptive behaviors, etc. For each, you make connections to evolution and reinterpret them under an evolutionary point of view. I can't help but wonder, though, how much "progress" has skewed evolution over the past 200 years. For example: many diseases no longer affect us thanks to vaccines; many "fit" couples choose not to have kids; and mostly, our "self-consciousness" has led us to change the course of selection in many instances. Your take, though -- correct me if I'm wrong -- is that these very same behaviors can be explained from an evolutionary point of view. Is human kind, then, like Oedipus who ends up fulfilling its fate by trying to escape it? Or is it more that we "are what we evolve into" no matter what we do ... ?

RB: We very much “are what we evolve into”. The thing about evolution is it is a consequence of a banal historic process whereby some individual leave more descendants than others. Or more precisely some genes leave more copies of themselves than others. So you can tell where a population has been, but it is impossible to tell where it’s going to go. We can make rough predictions, based on which kinds of traits are related to reproductive success today, but the environment is ever-changing, and the relationships are complex. We know, for example, that there has been rapid adaptation to high carb diets since the industrial revolution, even in 4-5 generations, and so I would predict – if compelled – that various adaptations by which people avoid the foods that cause obesity, shed excess energy and also cope with the extra weight might currently be under selection. If the current obesity crisis persists, we will almost certainly adapt to it. But nobody can be quite sure how.

Yes, medicines alter the way selection operates, but they too are part of the environment now.

EEG: But take for example the natural tendency that we have, as a species, to maintain a 1:1 male to female ration, and yet the numerous disruption introduced by human behavior. It seems to me that the 1:1 male to female ratio is a stable point and no matter what we do (for whatever reason), there are forces that inevitably bring us back there...

RB: It’s true that the ‘Fisher condition’ restores population sex ratios to near parity in a very stable way, but the Trivers-Willard process means it can be highly adaptive for skewed sex ratios under certain economic conditions. And unfortunately the economic cues can persist and give effectively the wrong message as they are doing in northwest India, where so many families are behaving like the extreme high-caste individuals with ever-increasing tragic consequences. It will probably take a generation for the lack of prospects for sons to turn into a cultural change that restores value to daughters sufficiently.

EEG: What will your next book be about?

RB: I’m writing about the conflicts inherent to sex and why they make sex and family life so ridiculously complicated.

EEG: I'm already intrigued. I'll be on the look out for your next book!

If you, too, don't want to miss Dr. Brooks' next book, you can check out his website or follow him on Twitter. Dr. Brook also blogs on The Conversation.

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