As a naturalist, Erasmus Darwin formulated one of the first formal theories on evolution in Zoonomia, or, The Laws of Organic Life (1794-1796). Some of his ideas on how evolution might occur are quite close to those of Lamarck, but Darwin also talked about how competition and sexual selection could cause changes in species. Although he did not come up with natural selection, Darwin did discuss ideas that his grandson elaborated on sixty years later, such as how life evolved from a single common ancestor, forming “one living filament”. Often quoted poetic lines from Darwin’s The Temple of Nature, or, The Origin of Society (1803) clearly anticipate the outlines of his grandson’s theory by half a century:
Organic Life beneath the shoreless waves
Was born and nurs’d in Ocean’s pearly caves
First forms minute, unseen by spheric glass,
Move on the mud, or pierce the watery mass;
These, as successive generations bloom,
New powers acquire, and larger limbs assume;
Whence countless groups of vegetation spring,
And breathing realms of fin, and feet, and wing.
Interestingly, the house that Erasmus Darwin occupied for 25 years of his life (1756-1781) still exists in Lichfield in the county of Staffordshire, England and is maintained as a tribute to his genius.