Here On Earth: An Argument For Hope

by Tim Flannery

We have a tendency to use ideas such as selfish gene theory to justify our own selfish and socially destructive practices. It’s significant, I think, that Dawkins’ book received wide acclaim on the eve of the 1980s—the era when greed was seen as good, and when the free market was worshipped. As our experience with social Darwinism illustrates, we need to be eternally on guard against the siren song of self-interest if we wish to live in a fair and equitable society.

One of the iron-clad rules of physical evolution is that individuals cannot pass on to their offspring any favourable traits acquired during their lifetimes. Lamarck believed that giraffes could stretch their necks by continually reaching up for leaves, and that such stretched necks could be passed on to their offspring. Today we know that neck length among giraffes is coded in their genes, and that, with some rare exceptions (such as lengths of DNA inserted into genomes by viruses), physical traits acquired during an individual’s lifetime cannot be passed on. Cultural evolution, in contrast, is purely Lamarckian. It is fuelled by the spread of ideas, and technologies that flow from such ideas, and those acquired by one generation are passed on to the next. Cultural evolution is far faster than physical evolution: it took the sabre-toothed cats millions of years to evolve their great stabbing canines, but it took humans only a few thousand years to develop metal daggers that are far more potent weapons.

Selfish gene theory predicts that, in conflicts between genes and the bodies they create, genes will almost always prevail. But with the evolution of the mneme, all of that has changed. Humans have developed the idea (itself a mneme) of genetic engineering. The technology potentially allows us to snip genes we don’t like out of our genomes. Clearly, in our modern age mnemes trump genes. Indeed mnemes are the most powerful things in the world. Around two hundred years ago a man called James Watt developed a mneme involving coal, steam and movement—and as a result the very composition of Earth’s atmosphere today is changed.