Nowadays, whenever anybody picks on Charles Darwin, it is likely to be some religious nut who know considerably less about evolution than about the literal inerrancy of Holy Writ. But back in 1859, when Origin of Species was first published, a lot of the criticism came from perfectly legitimate scientists. Many reviews of the Origin were pretty harsh in pointing out what they took to be flaws in Darwin’s work.
One of the most frequent criticisms never made a lot of sense to me. It struck me as one of those damned-if-you-do, damned-if-you-don’t kind of situations. Darwin, it seems, had said Natural Selection worked by preferentially selecting between the naturally occurring variations in living beings. Problem was, Darwin didn’t specify a mechanism that would cause variations in the first place.
What Darwin actually said was that variations are matters of observation, whether or not we know the exact reasons that cause them. It’s enough, he said, to simply note the fact of their occurrence and leave the discovery of a cause as a separate problem to be solved by others.
Personally, I’ve always thought that his naked admission of ignorance and his refusal to speculate was the mark of a good scientist. Interestingly, one of the favorite criticisms leveled at other scientists of the day was on their willingness to speculate on this or that without firm evidence. Hence the damned-if-you-do, damned-if-you-don’t comment.
There was, in fact, a popular theory of variation in species, produced by the one of the pioneers of evolution, Jean-Baptiste Lamarck. Studying fossils from the Paris Basin, Lamarck concluded that species varied as animals adapted themselves to their environments. Insofar as the actual mechanism of variation, Lamarck espoused what came to be called the use and disuse theory.
Essentially what he said was that any faculty or organ not used by an organism tended to atrophy and any that were essential to the organism tended to specialize. All well and good. Where Lamarck got himself into trouble was that he assumed that the changes produced by use and disuse were passed on to the next generation. Hence he explained the neck of the giraffe by suggesting that an animal that stretched its neck to reach the high branches would tend to have a longer neck and long-necked children!
Today, we know that variations are a result of modifications in the DNA and that the life experiences of an organism that don’t affect the DNA have no impact on the offspring. Hence the terms “Lamarckism” and “Lamarckian” are something like epithets in modern science.
Kind of a sad way for a pioneer to achieve linguistic immortality.
I think a pretty good case can be made for the idea that Lamarck was right…at least for human beings. That while all other organisms follow a Darwinian path, human beings follow both a Darwinian path and a Lamarckian highway.
Our ancestry stretches back billions of years, to the first self-replicating molecules, the ancestors of our DNA. For all that time, the Darwinian rules applied: develop a modification; if it’s beneficial, it might be naturally selected; if not, not.
But very late in our story, along about yesterday in fact, mankind created its greatest invention: language. And language changed the rules of the game. Specifically, with it we created our own Lamarckian world.
It works like this: Once upon a time there was a young caveman named Eck. One day Eck met a bear in the woods. Being a brave caveman, Eck pick up a stick, waved it, and shouted to chase the bear away. Unfortunately, this was a she-bear with a cub. Within a short and very messy time, there was nothing left of Eck but a lot of bear scat.
Since Eck died too young to have offspring, from a Darwinian point of view Eck contributed nothing to the human race. But from a Lamarckian perspective, he was pretty important. For generations afterward, the story of Eck the Scat was used to teach young humans the dangers of she-bears with cubs. Which increased the survival probability of the species.
It was language that allowed human beings to create a store of knowledge that survived the creators of that lore. Our laws, our legends, and even our science have all depended on our ability to create messages that will survive us.
As they say, there’s good news and bad news.
The good news is that Lamarckian evolution is fantastically fast. Once human beings developed language, we created civilizations and technologies and outran all the other species on the planet.
The bad news is that our stored information has increased geometrically. This is bad because, a) our ability to filter out false data has lagged way behind our ability to store information, and b) our facility at storing things is surpassing our facility of indexing them.
In short, and in a nice irony, we are in danger of being buried by our own Lamarckian scat.