The answer is well known, of course: Sex is required to provide genetic variability. But what does “producing genetic variability” really mean? Well, it means that while natural selection is busying itself with the task of perfecting organisms for efficiency, sex is doing the exact opposite. It is busying itself with screwing them up. The fact that sex is essential to long-term survival on this planet is self-evident. Any species that abandoned sex must have been eventually whisked into extinction. Sex, then, is a system that shows phenomenal evolutionary foresight—it plans for the future—but that makes no sense, either. Evolution has no foresight whatsoever. It operates strictly on a generation-to-generation basis and has no idea what traits will be most successful in 1,000 generations.
Sex is best seen as a regulating device that tempers the tendency of natural selection to ensnare species in an efficiency trap. Unregulated, natural selection would repeatedly drive organisms to the highest level of efficiency, but it would also drive them to the highest level of simplicity. The most efficient organism, a success in its environment, would out-compete less efficient individuals and natural selection would drive the less efficient organisms into extinction. Eventually, the most efficient individuals would be producing super-efficient identical clones of themselves, and these offspring would be successful, too—but only while the environment remained unchanged. Super-efficient clones would benefit from the energy savings of abandoning sex in the short term, but they could never last.
Changes in the environment, such as decreased rainfall, increased temperatures, or lower humidity, might leave an organism high and dry in a place to which it is no longer well adapted. Even more dangerous would be changes in an organism’s food supply or adaptation in its predators and parasites. Unable to respond to changing threats, super-efficient clones would lose their edge and find themselves vulnerable. No longer able to evolve apace with the rest of the biological world, their eventual demise would be assured.
We seem to have great faith in the capacity of efficiency solutions to avert the confluence of environmental and economic problems we face. The gathering storm of climate change, largely the consequence of burning fossil fuels, is intimately linked to our looming energy crisis as fossil fuel reserves decline. These two wicked problems seem to have the same solution: Use fossil fuels more efficiently. I’m sorry, but that’s a short-term fix that merely clones a doomed experiment in the hopes that it can keep going a few years longer.
Much more valuable would be to develop a more diverse portfolio of energy sources, but the problem of efficiency looms here, too. We seem to be trying to plug new energy sources into the centralized system that we developed and streamlined over the last century. We’re hoping for bigger, more efficient wind farms, solar arrays, and biofuel refineries. If only we can make these (mostly) more benign energy sources more efficient, we say, our energy crisis can be averted. Let’s swap out the nasty hydrocarbons for clean, green alternatives. If only it were that simple.
Our ability to extract natural resources, to compete, to develop new technologies and to streamline our business develops apace: We become increasingly efficient. But our resilience erodes. We lack checks and balances; we lose diversity and robustness; we find ourselves perfectly adapted to the world as it is. But what if the world should change?
To find our steady state and solve the sustainability puzzle our greatest needs are neither more energy sources nor more efficiency. Rather, we need to abandon the delusion that growth is a measure of progress. Only progress in diversity and beauty can stand the test of time. So relax, take it easy, spend more time with the one you love, and remember: The key to a sustainable future is sex.
The true genius of ecosystems is not their ability to keep growing and consuming, but to adapt, and more than 1 billion years after sex first evolved, it remains a requirement for long-term survival. It is expensive, risky and cumbersome, but life on earth has found through bitter experience that the surest path to extinction is to abstain from sex and fall into the efficiency trap. The antidote for efficiency in the natural world is sex. We need to find similar antidotes to efficiency in the modern world.