One major complaint people seem to have about a worldview free of supernatural elements is the perceived lack of meaning. Especially when confronted with evolution, some people will go “but that renders it all pointless”! The irony is that not only do I as a person lack an objective and final answer to “What is the meaning of life?” but that I also simply can’t define the word. As a future biologist, one would assume that I could at least answer it from a scientific perspective. What does “life” mean? What is life?

The rather curious answer is, we don’t really know. Seed Magazine has a story on this. I think it’s pretty good, and I agree with several of the points made by the philosopher Carol Cleland. Until we find life that is radically different from the kind we have here on earth, it’s going to be very difficult to define what life actually is. And besides, does it really matter? We seem to have some intuitive feel for how to divide biological systems from other systems, perhaps that is enough for the time being.

One thing Cleland says strikes me as a bit weird though:

Cleland, for example, doubts that Darwinian evolution, the core of the NASA definition of life, is essential. “I think those arguments are weak,” she says. She envisions alien microbes filled with enzymes but lacking genes. The enzymes build more enzymes and the microbes split in two. They couldn’t evolve through Darwinian evolution, because they wouldn’t have genes. But they might still change, as their environment changed. Cleland doesn’t claim any evidence that such things exist, but she argues that scientists can’t rule them out.

Strictly speaking, if you’re talking about evolution the way Darwin saw it, genes don’t come into it. Darwin made no mention of them, because he had no idea what genes were. In fact, that he didn’t know the mechanism for inheritance was his main issue with his own theory, as far as I’ve understood it.

Also, enzymes building more enzymes whereafter microbes split in two does not seem like a process outside of natural selection. The mechanism of inheritance may be different from what we’re used to, but it’s pretty much how biologists today envision the origin of life. Anything that replicates is subject to selection - Richard Dawkins has even chosen to define “gene” as being “a unit of selection” in at least one of his books. By that logic, a self-replicating enzyme of any chemical composition is a gene in itself.

Still, one wonders what a creationist would make of the fact that a biologist can’t even define their subject of study. Not only is “species” a nebulous concept but life itself can’t be defined! Is this god messing with our brains, or simply failing to make nature clear-cut and well organised like we used to assume it was back in the days when we didn’t really know much about it?

life, biology, evolution, natural selection