Why do bees die after stinging you?

Honey bee stings have a barbed ratchet mechanism that pulls the stinger into the initial wound. This didn’t evolve as a suicide mechanism – honey bees can pull their stings out after stinging other insects. It’s meant to drive the stinger in as deep as possible; it just happens that mammal skin is too fibrous to release the sting, so the abdomen is torn open when the bee tries to escape afterwards. Honey bees are the only species to suffer this fate, but the cost to the hive of losing some workers is worth it for an improved ability to repel honey thieves.

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.