Habituation and Novelty

Beginning in infancy and throughout the life span, humans are motivated by newness, change, and excitement. Habituation, the tendency to lose interest in a repeated event and gain interest in a new one, is one of the most fundamental human reflexes. If the thermostat were to suddenly turn the air conditioning on, you would hear the loud humming sound begin, but within minutes you couldn’t even hear it if you tried. Habituation, a fundamental property of the nervous system, provides mechanis...

 There Are Many Types of Islands

IMAGINE a world without islands. Biologists often use the word 'island' to mean something other than just a piece of land surrounded by water. From the point of view of a freshwater fish, a lake is an island: an island of habitable water surrounded by inhospitable land. From the point of view of an Alpine beetle, incapable of flourishing below a certain altitude, each high peak is an island, with almost impassable valleys between. There are tiny nematode worms (related to the elegant Caenorh...

 Animals Evolved onto the Land and Took the Ocean With them

If you go back far enough, everything lived in the sea - watery, salty alma mater of all life. At various points in evolutionary history, enterprising individuals from many different animal groups moved out on to the land, sometimes eventually to the most parched deserts, taking their own private sea water with them in blood and cellular fluids. In addition to the reptiles, birds, mammals and insects we see all around us, other groups that have succeeded in making the great trek out of life's...