Often, when school students learn about evolution, Darwin himself becomes almost a footnote.They might hear about Darwin's postulates, setting out his understanding of how natural selection operates to shape the evolution of populations. They might also hear about 'Darwin's finches' - the little Galapagos birds that supposedly gave him a eureka! moment. I suspect that in many cases, that's it as far as Charles Darwin is concerned (although I'd love to be proved wrong!). And that's such a pity.
It's a pity because there's so much more to science than simply learning a series of facts. Scientists aren't simply walking repositories of factual information: they're curious about the world & how it works; they show a healthy scepticism about unusual or unsupported claims; they think critically about their work; and they recognise the importance of evidence. Somehow we need to convey this to students, if they're to truly understand the power & significance of science. And more than ever, we need those students to want to enter into science careers themselves - to see themselves as scientists. Both these ends can be served by talking, not just about the science, but also the people doing the science. Taking this sort of approach to teaching evolution can enhance people's understanding of the subject, because it contextualises it, shows how the ideas were developed, & in fact shows the nature of science itself (e.g. Cobern, 1994).
So, back to Charles Darwin. Perhaps the best-known images of him show a bearded old patriarch: elderly, dignified &, in those images, distant. Students might admire him, but would they want to emulate him? He's up on a pedestal, untouchable. So we tend to forget that when he began the intellectual journey that led to the concept of descent with modification, by the process of natural selection, Darwin was a young man, at the height of his physical powers. And before that, a fairly ordinary boy: youngest-but-one in a large, loving family; prone to the usual stuff that kids do (including 'doing chemistry' in the garden shed with older brother Erasmus - as a result Charles' schoolmates nicknamed him 'Gas'); an average student who disliked maths & continued this dislike into his university years: I attempted mathematics, and even went during the summer of 1828 with a private tutor (a very dull man) to Barmouth, but I got on very slowly. The work was repugnant to me, chiefly from my not being able to see any meaning in the early steps in algebra. (But before any of you start thinking, well, Darwin didn't like maths & seemed to do OK, so why should I bother - look at his subsequent comments: ...in after years I have deeply regretted that I did not proceed far enough at least to understand something of the great leading principles of mathematics, for men thus endowed seem to have an extra sense. You really do need a bit of maths, if you're intending to go on in science.) So a take-home message from this could be - see? 'Ordinary people' can also be great scientists.
As for Darwin's conceptualisation of the process of evolution - it's useful to talk about how this happened. It certainly wasn't an idea that sprang fully-formed from his mind. Certainly the young Charles Darwin was predisposed to consider evolutionary ideas. His own grandfather, Erasmus (senior) had written about the process of organic change in his popular biology books. Jean Baptiste Lamarck had proposed a mechanism by which that change might happen. Darwin would have been familiar with this. And then there were his teachers: for example, while at Edinburgh, he'd attended lectures by Robert Grant, a Lamarckian thinker who also took Darwin on field trips along the coast. (That relatively short time in Edinburgh - just a couple of years - had quite a big impact on Charles: while he was completely put off the idea of a medical career, he was also introduced to the practice of science, & in fact wrote his first paper while a student there.)
But nonetheless, when Darwin boarded the Beagle, he still accepted the widespread creationist view of life's origin & diversity, & admired William Paley's 'natural theology' (these days reinvented as 'intelligent design'. But the experiences he had & the observations he made (in geology, biogeography, palaeontology & biology) on that 5-year voyage - during that 5-year voyage of discovery set his thoughts on another path. A path that was further illuminated by Darwin's voracious reading, which included works by Charles Lyell & Thomas Malthus - both of whom . That statement of Isaac Newton's seems just as apt here - "If I have seen further than others, it is because I have stood on the shoulders of giants." Scientists build on & extend the work of others; it's rare for someone to make a major discovery that's completely uninformed by the research and understanding of their colleagues & predecessors.
And that collaboration & connectedness continued for the rest of Darwin's life. Although after a couple of years in London he moved to the country, with his wife Emma & the first of his extensive brood of children, & stayed there for the rest of his life, he was intimately connected with the scientific community. A steady stream of letters bridged the miles between Darwin and his colleagues in England, Europe, and the rest of the world. Visitors came & went, & his publications mounted up. he may well have lived a quiet life in the country, but he was no hermit!
What about the theory itself? 'Theory' in the strong, scientific sense of an testable, predictive explanation for a large body of observational and experimental data? When he walked down the Beagle's gangplank for the last time, in 1836, Darwin already had a head (& many notebooks) full of data & hypotheses about that data. In 1837, in 'Notebook B', he first wrote down his tentative thoughts about descent with modification. For the next 20 years, he busied himself with collecting data, looking to see if his predictions were borne out & his assumptions justified, and writing, writing, writing. When in 1859 he finally published his theory, in On the origin of species (following something of a wake-up call from Alfred Russel Wallace), it was out in the realm of science, for the rest of the scientific community to test in their turn.
And for the last 150 years that's what's happened. Some of Darwin's concepts have been shown to be incorrect - his ideas about inheritance, for example. But the theory itself has stood the test of time - and of scientists bent on testing it to destruction (that, too, is part of the nature of science) - and continues to underpin all of modern biology. And when we salute that massive scientific achievement, we should also salute the man behind the science, Charles Robert Darwin: thinker, explorer, scientist, devoted family man, keen observer of the beauty of the natural world.
PS This was written as part of the Blog for Darwin blog carnival - heaps more to read over there!