Can free evolutionary markets produce cooperation and charity? Sometimes, at least for microbes.

When most people think about evolution, they think of ‘survival of the fittest’, a mad dash for victory in a violent, selfish world.  We tend to think of charity and friendship as uniquely human traits, requiring our powers of reason and abstract thought — not to mention our complicated moral beliefs — to be stable.

But when we look at nature, we see examples of apparent cooperation at every level from fancy mammals like ourselves all the way down to microbes.  A major challenge in evolutionary theory is to figure out how Darwinian selfishness can produce social cooperation.

One theory (proposed by us) maintains that some biological functions make cooperation virtually inevitable.  These functions are leaky, meaning that it’s essentially impossible for an organism to perform them without unintentionally contributing to the well-being of its neighbors.  This theory is called the Black Queen Hypothesis, or BQH — the name comes from the card game Hearts, where the winning strategy is to NOT win the black Queen of Spades.

The BQH was originally proposed to explain why many marine microbes have evolved to be dependent on each other for apparently indispensable functions. We used experimental laboratory evolution to demonstrate that the simplest (and most restrictive) case of BQH-style evolution could be stable in an environment where organisms must remove a toxin from their environment in order to grow.

The BQH has attracted a lot of attention since it was published in 2012. There are lots of other possibilities for projects related to the BQH. Some include:

  1. What functions are eligible for BQH evolution?
  2. What happens in communities with multiple leaky BQH functions?
  3. Was BQH evolution important in the early evolution of life?
  4. Can we find signatures of BQH interactions in field samples of microbes?