On 12 February, we remember Charles Darwin’s birthday. His remarkable contribution to human knowledge, On the Origin of Species (1859), sets down the evidence and arguments for evolution by natural selection. By taking a scientific approach, Darwin (1809–1882) and many others have changed the way we understand our origin and place within the biosphere.
Humanists hold science in high regard. We are confident that scientific knowledge has a high degree of reliability and can be trusted. If people claim to have gained knowledge by other means, e.g. revelation, hearsay or intuition, Humanists will view sceptically such claims until they can independently be verified by scientific investigation. For science differs from such unverified claims by being evidence-based, collaborative, open-ended and self-correcting.
Doing science, in a basic ‘suck-it-and-see’ way, has always been essential to human survival. Like all animals our forebears would have observed natural phenomena in their environment. From such observations came knowledge about survival in particular locations.
When our ancestors acquired language, they gained an effective way to pass information down the generations. Language probably also coincided with the propensity of humans to make-up hypotheses and theories about how things come to be the way they are. Today we regard these earlier ‘imaginings’ as the myths, folklore and religious beliefs of particular groups of people.
The revival of learning in the Renaissance period encouraged people to be more adventurous. It led to an expansion in trade, exploration and colonisation by Europeans, followed by the development of natural philosophy. Early practitioners were especially interested in the ancient Greek and Latin texts on astronomy, animals, mathematics and plants, practical manuals of how things worked.
However, conflict between traditional scholars and the early natural philosophers (later called scientists) meant that the latter worked outside the existing universities. These men, usually of independent means, were the founders of modern science. They made observations, did experi¬ments, wrote papers and sent them to other natural philosophers in different parts of Europe. They also founded the first scientific journals and formed the early scientific associations such as Accademia del Cimento (Tuscany), the Royal Society of London and Academie des Sciences (Paris).
Darwin followed in the footsteps of those natural philosophers and naturalists, and we can learn a lot about the methods of science from the way he went about assembling evidence for species change by natural selection. As a young naturalist he had the extraordinary good luck to spend five years journeying around the world on HMS Beagle.
While going around the world he collected specimens and took detailed notes of what he observed. Shortly after his return to England he married and settled, in 1842, into a domestic haven in Downe, Kent, where he lived for the rest of his life. After that he rarely travelled far from home, spending much of his time as a practicing scientist – reading, corresponding, experimenting, thinking and writing.
While travelling on the Beagle, Darwin saw a vast number of different plant and animal species. The question of how they had come to be so varied presented itself. He was well aware that the suggestion that species were able to change, i.e. evolve into different forms, ran counter to the established understanding of the fixity of species – a view which seemed common sense and was reinforced by the bible – god had made all the plants and animals in the form in which we saw them.
When in the 1840s others had written about life forms evolving, even established scientists of Darwin’s day were sceptical. So when the idea of species change by natural selection occurred to Darwin, he delayed publishing an account on this matter for fear of ridicule from his peers. He was also not comfortable with the fact that atheists and freethinkers were among the first to promote the idea of evolution.
In 1858 Darwin was disturbed to receive a letter from another naturalist, Alfred Wallace, outlining natural selection. Although Darwin had confided his ideas about natural selection to a few science friends, he had published nothing on this controversial matter.
To alleviate Darwin’s worry about being denied recognition, his friends organised for him to present a short paper along with Wallace’s letter to the AGM of the Linnean Society in 1858. Neither man was present at that meeting.
Darwin then worked at length to assemble all his notes into a book On the Origin of Species. His aim was to convince others, especially his scientific peers, of the evidence and validity of his theory of natural selection. His approach was to set out the evidence that he had garnered from his travels, reading and correspondence, in an objective manner so that even a critical reader would be convinced of the validity of his interpretations.
Like any great scientist Darwin never considered he had written the last word on natural selection. Up until his death in 1882 he continued to modify and rewrite sections of his great book as it went through many editions.
It is for his contribution to human knowledge and his intelligent use of the open-ended methods of science that we celebrate Charles Darwin on 12 February.