I’ve just finished reading Charles Darwin’s Voyage of the Beagle (1839) and The Origin of species by means of natural selection (1859). Darwin was a man with an interest in explaining the world around him, collecting and studying anything and everything. Fascinating. I wish the books had been recommended when I was at school, but in the 1960s/70s Darwin was old hat and nobody suggested it.

However, when you read the books, and I hope you do, you realise that they are like texts for practical biology experiments.

For example, he visited many islands and found that snails occurred and many other things that could not fly. So, at home, Darwin put freshwater snails in an aquarium and dragged a duck’s foot through the water, then examined it. He eventually found some baby snails attached themselves. He took living terrestrial snails and put them in sea water. Some sank and died almost immediately, but some had made an operculum (a seal to their entrance) and these floated and remained alive in sea water for up to 20 days. Darwin did the same for seeds of many different plants with similar results.

Furthermore, and this is a little harder for school or home experiments, he looked at the poo of birds that feed on freshwater fish, to see whether seeds or eggs passed through from the fish gut to the bird poo and remained viable.

On the islands he found loss of wings was common amongst the insects and speculated it was because their loss prevented insects being blown away. I saw the results of this on a recent trip to Lord Howe – the strandline of a leeward beach had numerous dead specimens of a recently arrived pest species of bug. The flightless Cormodes darwini, a beetle I’ve been studying out there, was named because the descriptor was so impressed by the prediction in the Origin that such a beetle could occur. Darwin also suggested that those species which retained their wings should have relatively larger and stronger wings to maintain their flight on windy islands. I haven’t thought about this and am wondering if it’s true for Lord Howe. Time to get the ruler out.

Brilliant, islands sorted.

The baseline of Darwin’s theory is variation and survival of varieties. At home he studied varieties of all kinds of domestic animals and plants, doing simple experiments on cross fertilising plants in his garden and looking at competition between weeds.

Of course he famously missed out on understanding inheritance through genes in chromosomes, as discovered by the monk Gregor Mendel while Darwin was writing the Origin. But he was close.

I’ve mentioned just a few of the experiments mentioned in the Origin that could be replicated fairly easily. There’s a website run by Cambridge University for people interested in redoing his experiments here: www.darwinproject.ac.uk/learning-resources