Brainy................................

     In Aesop's fable "The Town Mouse and the Country Mouse," two cousins exchange visits, during which the city mouse turns down his nose at humble country fare, and the country mouse discovers that city life, while richer, is unbearably dangerous.  I'd rather gnaw a bean that be gnawed by continual fear, he wisely opines.  But thanks to us, today's city mice are growing big brains to outwit the ambient dangers.  Not just mice.  According to researchers at the Bell Museum of Natural History at the University of Minnesota, we've caused at least ten urban species - including voles, bats, shrews, and gophers - to grow brains that are 6% larger than those of their county cousins.  Heavens, smarter rats!  That's a scary thought.  As we felled and planted over their woods and meadows, only the cleverest animals survived, by tailoring their diet and behavior to the human-dominated landscape.  Those who did passed  big-brained genes on to resourceful offspring.  And they were the lucky ones.  Not all plants and animals can evade us or evolve:  only the most flexible endure.

-Diane Ackerman,  The Human Age:  The World Shaped By Us