February the 12th is the anniversary of Charles Darwin’s birth.

Across the world people will be marking the day by remembering Darwin the discoverer of evolution by natural selection, Darwin the cautious husband, Darwin the barnacle boffin and maybe even Darwin the geologist who explained the origin of coral atolls. I might be the only person who takes some time today to remember Darwin as a grumpy young traveler.

Darwin in New Zealand

Darwin visited New Zealand in 1835, and he really didn’t like it.The New Zealand visit came four years into the HMS Beagle‘s voyage, and at the end of a four thousand kilometer journey from Tahiti. Darwin and the Beagle’s crew had loved their time in Tahiti (Darwin records that “every voyager … offered up his tribute of admiration” to the island p 416). With the memory of Tahiti in mind, the sight of fern-clad hills, a few European houses and a single waka to act as a greeting party was a disappointment for Darwin:

Only a single canoe came alongside. This, and the aspect of the whole
scene, afforded a remarkable, and not very pleasing contrast, with our
joyful and boisterous welcome at Tahiti. (p 417)

Closer inspection of the land around the Beagle’s mooring in the Bay of Islands didn’t do much to improve the young Darwin’s opinion of New Zealand

In the morning I went out walking; but I soon found that the country was
very impracticable. All the hills are thickly covered with tall fern,
together with a low bush which grows like a cypress; and very little
ground has been cleared or cultivated .. (p 418)

And if the plants weren’t enough,  introduced predators had already removed much of native fauna:

I saw very few birds.. It is said that
the common Norway rat, in the short space of two years, annihilated in
this northern end of the island, the New Zealand species. In many places
I noticed several sorts of weeds, which, like the rats, I was forced to
own as countrymen. (pp 427-8)

In nine days of traveling around the Bay of Islands Darwin found very little to like. In comparison to the Tahitians the Māori were “of a much lower order” (p 420) and the Europeans inhabitants where “the very refuse of society” (p 420). In fact, the only place he liked was William Williams‘ attempt to remake England at the Mission house in Waimate North. (pp 425-30).

Now, it is obvious that Darwin meet New Zealand at a bad time. The capital, Kororareka, had well and truly earned its nickname as the “Hell Hole of the Pacific”, Maori where adjusting to life alongside Europeans, and the impact of the Musket Wars and the native flora and fauna was already in decline thanks to the introduction of pests and the clearing of forests. But when you consider that Darwin was in the Bay of Islands in summer time I don’t think I’m being too parochial  to suggest Darwin was being just a tad grumpy when he decided there was nothing to like in our country:

New Zealand in Darwin’s thinking

Darwin didn’t think much of New Zealand while he was here, but I suspect he ended up regretting the brevity of his visit. About 30 years after he gladly left our islands behind, Darwin wrote a letter to Julius Von Haast to thank him for some information he’d provided, adding

I really think there is hardly a point in the world so interesting with respect to geographical distribution as New Zealand

Darwin spent a lot of time thinking about  the geographical distribution of species. His first written account of where species might come from was spurred by thinking abut the distribution of Galapagos and Ecuadorian mockingbirds*. More importantly, if Darwin was going to do away with the popular idea that each continent’s species arose more or less in their current place, he had to work out how plants and animals could get from one place to another.

He developed contacts in New Zealand and his correspondence with other scientists has many references to our plants and animals. The presence of flightless birds, bats and the effects of glaciation all come up multiple times. But New Zealand’s most important influence on Darwin’s thinking came via his best friend, Joseph Hooker .

Like Darwin, and many other Victorian naturalists, Hooker started his career by jumping on a ship and sailing to the other side of the world. For Hooker, that meant the HMS Erebus and trip to Antarctica via South America, New Zealand and Australia. Hooker had read Darwin’s Journey of the Beagle in proof before he set off, and when he returned to England the two stayed in contact.

In 1844 Darwin “confessed” his ideas about the origin of species to Hooker. That letter contains references to the New Zealand flora, in which Darwin is fishing for facts that might support his ideas about species moving from one land to another. In the same year, Darwin started a discussion with Hooker about the distribution of Kōwhai (Sophora). The yellow-flowering Kōwhai will be familiar to all New Zealanders, but it may come as surprise that some of the “Kōwhai” species sold in garden centres aren’t from New Zealand at all, but are Chilean Sophora species. The species are similar enough they’ll happily hybridise given the chance.

These Chilean Kōwhai are an example of a common pattern – the floras of New Zealand, Tasmania South American and the sub-Antarctic seem to be closely related. Hooker thought this pattern arose because all these island where connected in a southern super continent. Darwin didn’t like the idea of creating new land to explain a biological pattern, and instead proposed that that chance dispersal (by wind or rafting) could explain the distrbution of these species. Darwin was a keen experimentalists, and so, he set about dropping seeds in salty water and attempting to germinate them. These experiments took place in Darwin’s house in Down, and apparently his children counted each germination as a victory for their dad over Hooker.

It seems Hooker couldn’t provide Kōwhai seeds for Darwin’s experiments, but Darwin took a record of just three equally-sized Kōwhai trees on the Chatham Islands (some seven hundred kilometers from the mainland) as evidence for long-range dispersal, and perhaps a suggestion that Kōwhai seed could survive a trip from Chile to New Zealand.

It turns out Darwin was right about Kōwhai  although he got the direction wrong. Molecular studies have shown that Sophora arose in the Northern Pacfic, dispersed down to New Zealand and arrived in Chile via the Antarctic’s strong circumpolar current, all in the last few million years (Hurr et al, 1999 doi: 10.1046/j.1365-2699.1999.00302.x).

Honouring Darwin Day in New Zealand

I’m not quite sure how I feel about Darwin Day. There is not doubt that Darwin was a genius, an exellent naturalist and the founder of a field of study that lives on today. But there is something a bit odd about the annual veneration of Darwin, and the rush to connect modern ideas in evolutionary biology with things Darwin wrote 150 years ago.

Darwin got a lot right, and foresaw many developments in the study of evolution. But evolutionary biology is much more than 21st century ‘Darwinism’. Darwin didn’t know what a gene was, so is unlikely to teach us much about genomics. For me, the most important thing to learn from Darwin’s writing is the way he set out about understanding the world. Darwin sought out evidence for each sub-hypothesis in his Big Idea, sometimes that meant writing to colleagues like Hooker and Haast and sometimes that meant doing experiments like his salty seeds.

Darwin never got a Kōwhai seed to experiment with, but, in his 1958 lecture on Darwinism in New Zealand, AC Flemming mentioned a study that found they can survive 4 months of immersion in salt water. That’s a little shorter than the time you’d expect a seed pod set adrift from New Zealand to take before it washed up on a Chilean beach. Right now, highschool students are starting another year of biology classes – and teachers are probably preparing another re-hash of the “plant study” they’ve taught to Year 13 students since they were called Seventh Formers. Wouldn’t it be a fitting tribute if some of those classes did something a little different, and honoured Darwin’s approach to undestanding the biological world by dunking Kōwhai  seeds and running an experiemnt he never got to?

*Forget about the finches