If you’ve been reading the news this week, you know that we’ve just been starkly reminded that the Earth is in the midst of a mass extinction – a biodiversity crisis like nothing it has experienced in 65 million years. Yet while species disappear at an unprecedented rate, new species are also being born all around us, and this fascinating process – speciation – is continuing just as it has been for eons.
But exactly how does one species become two? This is one of the biggest questions in biology. With funding from the National Science Foundation, Nathan Dappen and I followed National Geographic grantee Dr. Al Uy (University of Miami) halfway around the world to the Solomon Islands to document his cutting-edge research on speciation.
(If you don’t have time to read the whole post, be sure to check out the world broadcast premiere of our film “Islands of Creation” tonight at 8pm on Smithsonian Channel. But if you want to learn more about Uy’s work, read on!)
Despite its title, Darwin’s On the Origin of Species was largely silent on the question of how new species come into existence. During the 150 years following the publication of Darwin’s book, many of the world’s greatest biologists suspected that the Solomon Islands – a remote, volcanic archipelago in the South Pacific – would hold the key to understanding this biological mystery.
Uy’s research focuses on birds called Monarch Flycatchers, which differ in color and song from one tiny island to the next. The very same group of birds caught the attention of another explorer, the German evolutionary biologist Ernst Mayr, during the Whitney South Seas Expedition of the 1920s. Mayr’s theories about speciation, which were based largely on his observations of Monarch Flycatchers and other Solomon Islands fauna, revolutionized biology in the mid-20th century.
Mayr thought that the Monarch Flycatchers on different islands were “incipient species” – populations caught in the act of speciation. But in 1929, he had no way to test his hypothesis. Uy, arriving in the Solomons with 21st-century tools and techniques, was hoping to find answers where Mayr could not.
But working in the Solomon Islands isn’t easy. It’s hard to get government permits to conduct research, and the land is tribally owned, which means that Uy has to get permission to work from the chief of every village he visits.
Luckily, he’s made some great friends in the islands. One family in particular, the Murray family on the island of Makira, has adopted Uy as a member of their family. John and Joyce Murray are the patriarch and matriarch of the family. With their help, and a team of field helpers consisting mostly of the Murrays’ family and friends, Uy has been able to make impressive progress in a place where few other biologists have succeeded in working.
To study the flycatchers, Uy has to lure the birds into mist nets. Once he has captured a bird, he marks it with colored leg bands for identification. To determine whether the flycatchers recognize individuals from other islands as members of their own species, Uy deploys taxidermic flycatcher mounts and broadcasts flycatcher songs from a portable speaker. This is when the feathers really fly! Monarch Flycatchers are very territorial, and they’ll aggressively defend their territories against any bird they perceive to be a rival – i.e., a member of their own species. These clever experiments reveal that flycatchers are most aggressive toward individuals that look like them – supporting Mayr’s idea that the flycatchers on different islands are incipient species.
Now, Uy is discovering which genes are changing as these nascent species evolve apart – something Mayr couldn’t have dreamed of in the first half of the 20th century. Amazingly, the dramatic changes in flycatcher coloration from one island to another can be traced to just a few genes. In a very real sense, Uy may have discovered the genes responsible for speciation in these birds!
But as Uy continues his research in the Solomon Islands, he has also noticed a disturbing trend: the Solomon Islands as he knows them – his home away from home, and a pristine crucible of evolution – are disappearing before our eyes. The isolation that the Solomon Islands have enjoyed for millennia has come to an end, and international corporations are beginning to explore the resource-rich islands for timber, mining, and commercial fishing.
As a result, Dr. Uy has become a de facto conservation biologist. Traveling to remote schools and villages, Uy has begun arming locals with scientific knowledge about their environment and what they stand to lose if they allow their forests to fall. We watched as Uy gave a full lecture about his research – in Pijin, the local trade language – to a large, very attentive audience of local high schoolers on an island called Ugi. Afterwards, the students asked some really perceptive questions and seemed to engage with both the biology and the conservation message that Uy was trying to relate.
More and more scientists are finding themselves in Uy’s position – watching their research organisms, or entire research sites, disappearing faster than they can conduct their work. And, not out of self-interest, but out of a love of the natural ecosystem and human community in which they work, biologists who once studied nature simply to understand it are becoming conservation practitioners as well. Still, I haven’t seen many scientists make that transition as convincingly as Uy.
After spending 5 weeks with Dr. Al Uy in the Solomon Islands, we had all the material we needed to create a really cool documentary about his remarkable work there. Our film, entitled “Islands of Creation,” has its world broadcast premiere tonight at 8pm on the Smithsonian Channel (preview here; check your local listings). Tune in to see the full story of National Geographic grantee Dr. Al Uy’s amazing research in the Solomon Islands!
Neil Losin is a National Geographic Young Explorer. He received a Young Explorers Grant in 2009 for his Ph.D. research on invasive lizards in Florida and the Caribbean. Since receiving his Ph.D. from UCLA in 2012, Neil has been producing science and conservation films with his company Day’s Edge Productions.