A while back I wrote a review of a new book by Juan Enriquez and Steve Gullans: Evolving Ourselves: How Unnatural Selection and Nonrandom Mutation Are Changing Life on Earth. That review has just appeared in the Washington Post (free online at the link). For reasons that escape me, it’s in the “opinion” section, though perhaps the Post doesn’t have a book-review section. As you’ll see, my “opinion” wasn’t very high.
The main problem, as you’ll see in my short review, is that the authors failed to distinguish possible factors that could produce selection with selection itself, so the book was largely an exercise in speculation. One excerpt:
When the authors examine our own species, the evidence is even less convincing. Recent increases in diagnoses of autism, allergies and obesity are certainly real, but they have no obvious connection with how we’re evolving. Obesity makes that point: As hunter-gatherers we evolved to prize sweet and fatty foods, for they were uncommon but nutritious. Today these foods are ubiquitous — witness the yellow arches on every street corner — and our evolved penchant for such fare has become harmful. But the advent of McDonald’s and Big Gulps is not a genetic change; it’s an environmental one. While it’s possible that the health stresses created by obesity — diabetes among them — will produce natural selection for avoiding fats and sweets, that would be a glacially slow process, especially since selection is dampened because obesity-related health issues often arise late in life, after people have had their children. By the time selection eliminates Mom and Dad, the I-love-fats-and-sweets genes will already have been passed to their children.
The authors describe many more big changes in our society, including the heavy prescription of antidepressants and Ritalin. But what has this got to do with evolution? The authors’ point seems to be that these changes could potentially affect evolution by exerting selection on the human genome. But we don’t know that, because evolution depends on whether those cultural changes affect our reproduction and, if so, whether individuals differ genetically in their reproductive response.
At the beginning of the piece I reprise the evidence for modern-day evolution in H. sapiens—something I’m always asked about in my talks for the public. And, although we’re surely still evolving, we don’t have much hard evidence about what traits are involved and in what direction they’re changing. (I’m not counting the genetic evidence, based on DNA analysis, for “selective sweeps” in the last ten millennia or so.)
Good takedown. That bizarre bit in there about psychotropics really makes clear that the authors don’t “get” evolution.
b&
Very interesting and good review. Seems odd but it is surely an example of that Harvard Education not necessarily working out so well.
I enjoyed your review – the comments not so much. Your practice of not reading them is a good one. One person’s takeaway – let’s focus on the evolution of morality, which comes from Christianity! There’s no hope for some people.
I have given up debating one philosophy prof who always distorts the claim that morality evolved, ie our capacity for moral emotions and reasoning evolved, into the claim that evolved behaviour is moral. I am convinced god rots the brain: that belief actively impairs reasoning ability.
From reading your entire review, I would say the authors were way of their field. There were claims that could be refuted by a competent undergraduate biology major. Psychotropic drugs could have an impact on our evolution? Piffle. The authors needed to run the manuscript past a colleague who knows a thing or two about evolution.
Sub
A very common side-effect of anti-depressant medication is erectile dysfunction so perhaps there is a sniff of a chance that it could possibly effect evolution a little.
Also, loss of libido.
I see two big fails. First the authors didn’t think of passing their lame idea to a competent biologist to do a quick sanity check. Second big fail – WAPO didn’t think of passing their lame idea past a competent biologist to do a quick sanity check. Call me cynical but, I bet they thought the article would garner clicks so they didn’t think doing basic validation would be in their interest. Ignoring their reader’s interest seems to have become part of modern journalism.
Reading across your review, their approach seems to be based primarly on two tricks:
First, don’t have a clue what evolution is.
Second, define everything humans do as “unnatural”, and thus they get to say that all species somehow influenced by us even in the most indirect way are now undergoing unnatural selection.
Of course there is a certain kind of techno-optimist who will always swallow a book that tells them we humans are in charge now and everything will be totally different. I’d say we have to wait and see another two hundred years at least. I wouldn’t be surprised if the combination of overpopulation, unustainable resource depletion and global change would collapse us back into another dark age; and the question is if humanity can every crawl back to solar power and genetic engineering if it doesn’t anymore have easily avialable oil as a stepping stone. If the long term (= thousands of years) sustainable mode of living for humanity is something like early 19th century Europe/China then our being in charge of evolution would be very limited.
I was wondering whether we males would evolve indentations around the top of the thigh area from wearing tight budgie smugglers in the early 70’s, needless to say it didn’t happen.
Seems that publishing company should have had an evolutionary biologist on tap to go over the premise of the book first. Before this thing is written and published then sold.
I thought Lamarck was dead? Nope, his ideas remain strong.
I’m curious about your ending statement about not counting selective sweeps in the last ten millennia. Do you mean that, DNA evidence shows that selective sweeps occurred, but it is not known what associated advantageous traits are being selected for?