Sunday, May 11, 2014

Crowdsourcing Taxonomy

Crowdsourcing is an old idea. All of the plants in Botanica Caroliniana are the result of a large effort to crowdsource taxonomy.

James Petiver (1665-1718) was an apothecary in London. Petiver was a member of the Royal Society and a collector - of all sorts of things. Except for a brief period studying entomology in the Netherlands, Petiver worked in London. He kept a shop "at the sign of the white cross in Aldersgate, London."

Somehow Petiver got into the business of collecting natural history specimens, especially insects and plants. Ships were visiting all parts of the world, and Mr. Petiver and his friends evidently had an insatiable appetite for the curiosities they might bring back. So he started printing pamphlets asking for contributions to his collections, with explicit directions for collectors to follow for collecting and storing herbarium specimens. The collectors - Lord, Lawson - would package up their materials and send them to London when they could. Petiver then organized them according to some taxonomic scheme - if you look at the order of Lord's specimens, they are pretty much arranged by current families - and bound them in books.  By the time he died in 1718, Petiver had the largest collection of dried plants in the world.

Hans Sloane (1660 - 1753) jumped on this opportunity, purchasing Petiver's collections and many others, which eventually became the basis of the Natural History Museum, London. Sloane himself spent some time in Jamaica and is famous for his descriptions of Jamaican natural history, but the vast majority of his collection - some 120,000 specimens - came from people he never met and places he never visited. Catesby was one of his contributors. William Sherard (1659 - 1728), another of Catesby's sponsors, was doing much the same thing in Oxford.

The big man himself, Carolus Linnaeus, used this same business model. His travels were mostly restricted to places close by - Lapland, central Sweden, the Netherlands - and he did most of his work from his comfortable facilities in Uppsala. To fill his coffers, he sent his students on voyages of discovery. Daniel Solander and another student traveled around the world with Captain Cook. Others visited Japan, the Americas, Australia, and anyplace else they could reach. The ones who survived gave their specimens to Linnaeus, who worked them into his Systema Naturae.

Why do it this way? Well, for one thing, traveling was dangerous. Lots of Linnaeus' students died on their journeys, cutting short their aspirations for scientific discovery.

But more practically, you can't do two big things at once. Exploring and collecting specimens is one job. Assembling a collection is another. To make a collection, you have to be physically present at your research site, and you are encumbered by lots of stuff - camping gear, the specimens themselves. You can visit only a restricted area, and you might have to visit that area repeatedly to catch your subjects in bloom.

Assembling a collection, on the other hand, requires peace and quiet, a large flat surface and a roof overhead, lots of paper and glue, and reference materials. It's not easily done in the field. More importantly, a good collection requires a large body of specimens. Specimens from multiple collectors can offer perspective that the work of a single collector cannot. If you want to organize the world's plants, you need lots of contributors in lots of different places. You want to see the big picture.

This is how crowdsourcing works today. Project Budburst, the Great Backyard Bird Count, and NASA's Disk Detective program (sorting out stars with disks from nebulae and galaxies) all use non-scientist volunteers to collect and process data. The professional scientists then process what the citizen scientists send them, and the result is much better than they could achieve trying to gather data alone.

Like our historic collectors, today's citizen scientists are motivated by a desire to be part of something bigger - to make a contribution to science and maybe learn a little more science themselves. Lord and Lawson collected for Petiver out of interest in the world around them and the hope that what they saw might be of use - and as a way of making contact with London intellectual life, in short supply in the Carolinas in 1700. And their contributions did turn out to be real, useful both to the botanists creating modern taxonomy and to those of us studying them today.