A revolution in evolution is turning back the clock more than 200 years, says new book
Epigenetics is giving new life to Lamarck's theory of evolution
Today we know Charles Darwin as the father of the theory of evolution, but Darwin's wasn't the first theory of evolution. Before Darwin, a man named Jean-Baptiste Lamarck had a different idea about how life evolved.
His theory, like Darwin's, explained the variation of plants and animals around the world, but the mechanism was completely different.
Darwin's theory was that species were shaped over generations by natural selection — random variations in our genes appeared, and these made you and your offspring successful or not.
Lamarck's explanation for evolutionary change was that plants and animals — us included — were actually transformed by the environment in which they lived.
So, for example, the giraffe got a long neck because it had to constantly stretch up into the tall treetops for leaves.
Darwin's theory, of course, became the core of our understanding of evolution. Lamarck became the subject of ridicule.
But here's the thing: Lamarck might not have been entirely wrong. Recently, the relatively new field of epigenetics has been gaining traction and it harkens back to Lamarck's idea about the influence of the environment on our evolution.
Quirks & Quarks host Bob McDonald speaks with Dr. Peter Ward, a paleontologist from the University of Washington and author of the book, Lamarck's Revenge: How Epigenetics is Revolutionizing Our Understanding of Evolution's Past and Present.
This interview has been edited for length and clarity.
Bob McDonald: Now you preface your book by saying if Charles Darwin had known about the fossil record, he would have hated it. What do you mean by that?
Dr. Peter Ward: Yeah poor Darwin. He went to his grave, of course, not knowing about the field of genetics, but he also went to his grave really disappointed by the fossil record. He expected that a new species should show a bunch of intermediates, and yet the fossil record of his time didn't show that. Interestingly enough, in most cases, the fossil record of our time still doesn't show that, but not for reasons that Darwin thought. We now know that new species can form much faster than current Darwinian theory suggests.
BM: Well tell me a bit more about how epigenetics is different than Darwinian natural selection?
PW: Well one of the really comforting things about evolution, as I understood it, is that who of us has led a perfectly bad habit free life? But Darwin told us, and it was always comforting to me, that none of this would be passed on through our genes. Now we're finding this isn't the case. We're seeing that trauma and other types of environmental changes during our lives causes tiny little switches, tiny little bits of chemical to adhere to our DNA. We're not changing our genetic code, but what we're putting on is little pieces of duct tape, which can make a gene not work or in some cases, turning the gene on, which had previously been turned off. Now the new surprise is that some of these new additions are then passed on as information through the sperm and egg. This idea and actually the proof of this has been really rocketing through evolutionary theory for the last ten years.
BM: Well you say in your book that domesticated animals are a clue to what happens after a mass extinction. How so?
PW: We always think that we produce all those dogs and all those different kinds of chickens because eggs would be laid, one variant came out, we kept that one alive, and we killed the others. But increasingly, it's looking like domestication is starting this Lamarckian process. These little birds that run around, they spent all day A/ trying to find food and B/ trying not to be eaten, and then later finding a mate — when all three are given to you, your behavioural repertoire changes drastically because your environment has changed drastically. And so through the generations, we see their behaviour change, we see that domestic animals appear to be much more lethargic. But also we're finding enormous rates of morphological change.
BM: So how then would epigenetics be involved in the sort of the diversity of life after an extinction?
PW: Well epigenetics and their processes really are favoured during times of maximum environmental change. People are estimating that the change that epigenetics can produce can be three orders of magnitude faster than Darwinian evolution. For example, microbiologists began to put into strains of bacteria and other groups, poisons, toxins, major environmental change for those bacteria. The scientists then noticed that mutation rates vastly increased. So when we have stress, we respond to this through the formation of stress molecules, but also when we are bathing in stress molecules, it appears that mutation rates can increase quite rapidly. So higher mutation rates plus heritable epigenetics equals rapid evolution.