Evolutionary traps

” ON THE Caribbean island of St Kitts, a colony of exuberant vervet monkeys patrols the beach, waiting to pounce on unattended drinks. When they spot one, they scamper acrobatically across the sand to steal it. They fight. They drink. They overturn tables. Finally, as the sun slides over the horizon, they slump clumsily onto the sand.

Scientists have been studying the drunken monkeys of St Kitts for decades, using them to research the neural pathways involved in alcoholism. But they represent more than just a primate model of addiction.

According to biologist Bruce Robertson at Bard College in New York, the monkeys are caught in an “evolutionary trap”. Their enjoyment of alcohol exists for a very good reason, he says: they evolved to crave energy-rich foods. But now that piña coladas are easier to obtain than bananas, it has become a liability. “It’s an incorrect behaviour that happened because we changed the environment too fast for evolution to catch up,” Robertson says.

Evolutionary traps – also called ecological traps – are everywhere. They have been found in almost every type of habitat, affecting mammals, birds, reptiles, amphibians, fish and insects. Bamboozled by rapid environmental change, these animals can no longer accurately assess the suitability of food resources, mates, habitats or much of anything else. Bad choices look like good ones, and the animals are lured into an evolutionary dead-end.”

— excerpt from the article Trapped! (New Scientist issue 2960, 17 March 2014, by Christopher Kemp)

The article goes on to give examples of other animals that are facing decline due to the change in their environment, from newly hatched turtles crawling towards the city lights instead of the sea, to jewel beetles mistaking a beer bottle for a female and mating with it.  It’s eye-opening to see examples of the inadvertent destruction humans cause in the environment.

But there are two additional ideas in this article that fascinated me.  The first one is what Robertson calls “virtuous evolutionary traps”, a trap set on purpose, for example for mosquitoes carrying malaria. Ken Pienta is using it to trap metastasizing cancer cells — and calling it eco-therapy.

The second idea is that evolutionary traps apply to humans too. Behaviours that evolved to aid survival, hijacked to our detriment:  fast food, gambling, video gaming, drugs, pornography and so on. How can these be fixed?

The article is well worth reading. If you don’t have a subscription to New Scientist, this link seems to have the full text.