(Editor’s note: Sanjayan, The Nature Conservancy’s lead scientist, is traveling in the Solomon Islands to explore the amazing diversity of life and the fast vanishing marine and terrestrial habitats on these islands. As part of this expedition, Sanjayan’s experiences will be made available to students across the United States by the interactive curricula company Promethean Planet. Sanjayan’s stories from the field, photography, video and more will be developed into innovative lesson ideas to be used in classrooms equipped with interactive whiteboards. To learn more, visit Promethean Planet.)
If you want to study evolution (how things change over time through the process of natural selection) or study speciation (where and how species arise and diverge) you go to islands.
It’s not an accident that Darwin visited more islands on his famous voyage around the world than he did countries. Also, Ernst Mayr — the world’s preeminent evolutionary biologist in modern times — developed his concept of what a species is and his take on evolution and speciation after his visit to the Solomon Islands.
Decades later, Jared Diamond — a Pulitzer Prize winning author about the collapse of civilizations, and a major modern contributor to our understanding of evolution — also drew inspiration from the Solomon Islands.
Today, Dr. Chris Filardi (who is on our expedition) and others are adding to this long lineage of scientific discovery, continuing to refine the answer to the question that Darwin posed but never himself answered — where do all these species come from? Indeed, Darwin’s classic (On the Origin of Species) should have been posed as a question. Despite the title, he did not solve the problem of speciation — namely, how multiple related species originate from a single ancestral species. Darwin’s contributions instead have to do with the fact and mechanism of evolutionary change over time.
Islands are great because they are geographically bounded, they have fewer species to deal with, and the delineations between what is there and what is not there is pretty clear — they have sharp boundaries. For instance, Tetepare and Rendova — two of the islands in the Solomons chain — are just two kilometers apart, but have different species of the white-eye bird.
So islands and the species that live on them can tell us a lot about the origins of species and about evolution. Of course of all the species to work on, birds have some unique advantages in that they are conspicuous, and relatively easy to observe and collect in the field.
(Tetepare and Rendova, two islands in the Solomon Islands chain, with dolphins breaking the water’s surface in the foreground. Credit: Sanjayan/TNC.)