A few peas can occupy a gardener for an entire morning. Gregor Mendel took the matter considerably further.
Between 1856 and 1863, he cultivated and tested about 28,000 pea plants, according to the familiar historical estimate. He crossed plants, saved their seeds, grew the next generation, and kept careful records of what appeared.
The counting mattered.
Seed shape, seed color, and plant height were among the traits he followed. Patterns emerged when he compared generations. Traits that seemed to disappear in one generation could return in the next.
Those experiments helped establish the basic principles of inheritance. They do not describe every way that traits are inherited; genetics has since grown into a much larger subject. But the garden records were a beginning.
Few pea patches have left a more useful paper trail.
