Darwin’s Day: 4 Snapshots from the Evolution of Evolution

1: The Eclipse of Darwinism?

Before Mendel did his experiments with peas, the mechanism of heredity was unknown. This was thought to be a fatal flaw of Darwin’s theory of natural selection. Under then-current theories of blended inheritance, it was believed that adaptive mutations would be quickly swamped in the wider gene pool.

In subsequent editions of On the Origin of Species, Darwin increasingly relied on aspects of Lamarckian inheritance to plug these supposed leaks in his grand theory. Ironically, after the rediscovery of Mendel in 1900, Mendelians contributed to the so-called eclipse of Darwin, when Lamarckian use-and-disuse evolution briefly became ascendant.

Hey, maybe if I keep stretching to reach that higher shelf I’ll grow taller like Lamarck’s girafffes!

Lamarck never lived to see his theories embraced, nor Darwin his eclipse. Though textbooks often pit Darwinism against Lamarckism in an evolutionary cage match, the ebb and flow of acceptance and rejection was an ordinary part of the scientific process.

Read more: The Abuse of Use and Disuse