Heredity and Genetics: The Dialogue Continued
For all of Darwin’s keen observations about how life forms change, he was unable to explain exactly how traits are passed from one generation to another—a key piece of the evolutionary puzzle. His immediate successors sought answers outside the framework of his theory of natural selection.
In the early 1900s, research on heritable units called genes appeared to provide an alternate explanation. But by the mid-twentieth century, further work in genetics led researchers back to Darwin. His theory came to inform their work, and their work ultimately confirmed and expanded upon his. The result was a revised theory (the so-called “evolutionary synthesis”) that brought together research from many different disciplines.
With every new answer, however, have come new questions—and the dialogue with Darwin continues today.