Is the rate of human evolution increasing with population growth?

Larger populations create more chances for genetic mutations to occur, and this means more variations for natural selection to either favour or weed out. But in big populations, it takes longer for chances to spread. The fastest rate of evolution occurs when a population is split into isolated subgroups that can’t interbreed due to geographic or cultural barriers. Travel and communication have broken down many barriers, so our genes get blended together instead of splitting into subspecies. A 2007 study found that we are evolving about 100 times faster than at any other period in our history. But ‘modern’ for an evolutionary biologist means the last 5,000 years. It’s too soon to tell how our evolution has been affected by the population explosion of the last few centuries.

Could robots be programmed to evolve?

Yes. In research that was published in some time ago, teams in Cambridge and Zurich built robots that evolve through successive generations.

The ‘mother’ is a robotic arm that builds ‘baby’ robots out of small cubes. Each cube has a mechanism where one side can waggle. When you place it on a surface, it clumsily drags itself around. The mother glues these moveable cubes together in various arrangements. Some combination move further and faster than others. The mother robot builds each arrangement using assembly instructions in the form of a ‘genome’ that is passed between successive generations of robots.

The mother is programmed to insert random mutation into each generation. Some offspring move around better than their forerunners, but others do worse. The mother rejects deficient generations but uses the genetic blueprints of successful ones to build subsequent offspring. In the lab, after only 10 generations, the robots performed twice as well as those at the start of the process.