Back to Lamarck?

“Did you know that acquired characteristics can be inherited?”


Jean-Baptiste Lamarck

My daughter dropped that little bombshell on me one day after she came home from school.

“What kind of crap are they teaching you in that biology class of yours?” I grumbled.

“It’s called epigenetics,” she replied. “Look it up.”

I did. It blew my mind.

In previous posts, I wrote about Bernard Shaw’s attempt to found an evolution-based religion called Life Force Worship. Shaw’s ideas were based on the pre-Darwinian theories of Jean-Baptiste Lamarck. Here’s an admittedly crude and cartoonish rendition of the Lamarckian Story:

Once upon an extremely long-ago time, a certain hoofed animal ate all the leaves within easy reach. It then got into the habit of stretching its neck in order to eat leaves higher up. It passed along both the habit and an ever-so-slightly more elongated neck to its offspring. And lo, after untold generations of habit and inheritance, we now have giraffes in our midst.

Lamarckism eventually gave way to Charles Giraffe23Darwin’s theory of Natural Selection. Alas, according to this new idea, giraffes did not develop long necks solely through exercise and effort—by willing it, so to speak. Instead, giraffes lucky enough to be longer-necked managed to survive and procreate in the life-or-death struggle to reach higher leaves.

The process seemed (at least to thinkers like Shaw) to be intolerably random and mindless. Nevertheless, Lamarckism was relegated to the dustbin of defunct ideas—or so it was long thought.

Epigenetic_mechanismsI won’t try to explain how epigenetics works. I doubt that I’ll ever be able to wrap my own brain around it. The gist of it seems to be that, while our genes are pretty much inalterable, the expression of those genes is not. Moreover, acquired characteristics sometimes can be inherited. As Kara Rogers writes in Scientific American,

the implications so far suggest that our lifestyles and what we eat, drink, and breathe may directly affect the genetic health of our progeny.

What’s more, epigenetics may well offer possibilities for treating obesity, cancer, diabetes, addiction, aging, mental disorders, and all sorts of other bugbears of the human condition.

So has this new science given Lamarckism a new lease on life? There’s a lot of healthy skepticism out there. And I doubt that any serious epigeneticist is ready to claim that giraffes willed themselves into having longer necks. But epigenetics certainly looks like an inspiring plot point in the ever-evolving Story of life.

P.S. to “That Other Darwin”

In my previous post, I certainly didn’t mean to “diss” Charles Darwin by calling him the “consummate hedgehog.” The world of ideas must have its hedgehogs as well as its foxes. It is true that Charles’s überfox grandfather Erasmus anticipated a lot of evolutionary theory, including Natural Selection, many years before Charles got around to it. Charles’s contemporary, Alfred Russel Wallace, also figured out the basics. But neither Erasmus nor Wallace gathered the sheer weight of evidence needed to make their ideas stick. It took the world’s greatest hedgehog to do that.

And Charles came by his ideas the hard way, with no noticeable influence from his grandfather. True, he read a book by Erasmus when he was seventeen “in which similar views are maintained, but without producing any effect on me.”

Charles’s way was longer and more tortuous. To begin with, he had to let himself be amazed and puzzled by the sheer diversity of life he observed during his youthful, legendary, worldwide journey aboard HMS Beagle.

In an age in which the first two chapters of Genesis were almost unanimously accepted as the final authority on natural history, what was young Charles to suppose upon seeing his first platypus in Australia? Why would an all-creating God scatter such anomalous creatures in entirely different parts of the world? His earliest speculation was about as far from evolution as you can get:

An unbeliever in every thing beyond his own reason might exclaim, “Two distinct Creators must have been at work; their object, however, has been the same, and certainly the end in each case is complete.”

“Two distinct Creators”! It was as heretical an idea as Natural Selection would later prove to be. But young Darwin was not an “unbeliever”—not yet, anyway. Soon after his encounter with the freakishly odd platypus, he took comfort in noticing that the Australian antlion larva was very similar to a European species. Such a resemblance, he thought, could be no cosmic coincidence:

Now what would the sceptic say to this? Would any two workmen ever have hit upon so beautiful, so simple, and yet so artificial a contrivance? It cannot be thought so: one Hand has surely worked throughout the universe.

“One hand” creating, of course, in a manner consistent with Genesis. But Charles Darwin’s Story was just getting started.