1865 Gregor Mendel, a curious Austrian monk, publishes a study showing how living things-he was working with pea plants at the time-inherit physical characteristics from their parents and pass them along to their offspring. Cross short plants with short plants, for example, and the resulting crop will be (you guessed it) short. By crunching the numbers from many, many plant matings, Mendel realizes that individual traits are inherited separately-a tall plant can have green peas or yellow peas, just as a tall person can have brown eyes or blue. Incidentally, scientists believe that Brother Gregor-though he really did unravel the laws of inheritance-may have fudged his data a bit to make the pattern he found "cleaner." In real life, data never come out that good.