Living in the desert is a challenge. But the Mojave Desert woodrat has one trick: it can eat poison. This allows the cute little rodents to survive and thrive by feeding on the toxic creosote bush. Remarkably, it has not evolved the genes needed for this. Instead, it eats the droppings of other woodrats and thereby inherits the detoxifying bacteria that live in its gut.
The desert woodrat is an example of how the things organisms do can influence their evolution. And it’s far from sudden: in recent years, it has become clear that many organisms influence their evolution by creating non-genetic traits that may be subject to natural selection. This challenges traditional Darwinian thinking, which sees evolution as a process rooted in random genetic mutation. But that’s not all. These non-genetic forms of adaptation may help explain another puzzling aspect of evolution: evolution, or why some organisms are better able to evolve than others.
I belong to a growing group of evolutionary biologists who believe that non-genetic inheritance plays a vital role in evolution. This has practical consequences. In the face of climate change, species must adapt quickly or face extinction, and there is growing evidence that extragenetic adaptations, such as those found in the desert woodrat, can save organisms from the brink. The new thinking has implications for how we view our evolution. Our complex culture makes the evolution of humans very different and much faster than the evolution of most other species. This unusual…
