What was the name of Darwin's grandfather, also a naturalist?

Erasmus Darwin was Charles Darwin’s grandfather and a prominent eighteenth-century naturalist, physician, poet, and natural philosopher. He was the father of Robert Waring Darwin, Charles’s father, making him Charles’s paternal grandfather.

Born in 1731, Erasmus Darwin practiced medicine in the English Midlands and became a Fellow of the Royal Society in 1761. He was also a founding member of the Lunar Society, an influential circle that included inventors, industrialists, and scientists such as James Watt, Josiah Wedgwood, and Joseph Priestley.

Erasmus Darwin wrote extensively about plants, animals, and the development of life. His Zoonomia, published between 1794 and 1796, included early evolutionary ideas, including speculation that living things might share common origins. Charles later knew and read his grandfather’s work, although Charles’s theory of evolution by natural selection was a distinct and more fully developed explanation.

A common mix-up is confusing Erasmus Darwin with Charles’s sons, including George and Francis Darwin. Erasmus died in 1802, decades before Charles published On the Origin of Species.