I must leap to the defence of Charles Darwin's grandfather, Erasmus. It is not the case that, as David J. Hosken says in his Correspondence, “no one else envisaged anything like sexual selection” before Charles Darwin (Nature 458, 831; 2009). His grandfather had done so more than 50 years earlier.

In his book Zoonomia (Johnson, 1794), Erasmus writes: “the three great objects of desire, which have changed the forms of many animals by their exertions to gratify them, are those of lust, hunger, and security”. Lust, he goes on, leads to sexual selection: male birds fight so that “the strongest and most active animal should propagate the species, which should thence become improved”.

Erasmus is often lost behind the glare of his stellar grandson, but he should not be forgotten. In many ways, as readers of Zoonomia and his great poem 'Temple of Nature' will appreciate, he played John the Baptist to Charles's Jesus.