Page 8: Biology - Snake Hunters
These scientists search the world for venomous snakes and the evolutionary secrets their DNA holds.
It was a bright and sunny day in Itanhaem, Brazil-the port city from which Assistant Professor of Biology Christopher L. Parkinson and the rest of the team embarked. Their 3-hour boat ride took them to the uninhabited Isla Queimada Grande where he and his colleagues searched for the venomous Golden Lancehead Viper (Bothrops insularis). The sea was calm that day, and the team anchored their large boat about 50 meters from the rocky shore, which is only accessible by smaller vessels.
Parkinson held tight to his camera gear as the team paddled to the island, but, as the boat approached the land, a rogue wave struck it, sending the team flailing into the sea. Parkinson managed to clutch tight to his expensive photography equipment, and the others finally managed to pull him up, onto the rocks.
Parkinson is part of a multinational team of scientists who are as comfortable on the cold, rocky shores of a snake-filled island as they are in a genetics laboratory. Parkinson and his colleagues are studying the highly endangered Golden Lancehead Viper, found only on Isla Queimada Grande. Each year, several trips are made to the island to collect tissue samples and investigate this snake's natural history. They are tying to discover how it evolved and why it is found only on this one small island off the coast of Brazil.
Parkinson is a phylogenetic systematist, which means that he determines the evolutionary history of organisms and then categorizes them-discovering new species and giving each a name.
Back on the island, Parkinson and his colleagues pitch tents, grab their headlamps, and prepare for a night of snake collecting. They hike through the island's forests looking for Golden Lancehead Vipers coiled on the ground or on low-hanging branches. When the team finds one they document the viper's health, snip off a piece of a scale for DNA analysis, and implant a computer microchip for future identification. Then they release each one, unharmed.
Investigating the Golden Lancehead is only a small piece of the larger puzzle of the evolutionary history of venomous snakes in the New World (North and South America). In the New World there are two main groups of venomous snakes: coralsnakes and pitvipers. Parkinson uses DNA analysis to sequence the venomous snakes" genetic material and then categorizes them based upon their phylogeny, or evolutionary history. His goal is to categorize the tree of life for all venomous snakes using molecular sequence data. Once complete, this classification will enable scientists to learn more about the snakes" biogeography, time of origin, how and when the venom injection mechanisms evolved, and why there are differences in species richness across snake lineages.
Parkinson's work is important for biodiversity and human health concerns, too. Several drugs are made from various venom components and using the correct antivenom for the treatment of snakebites is paramount.
"Understanding the world's biodiversity is of great importance,": Parkinson says. "In recent times, the rate of extinction of entire species and habitats has increased dramatically. With each additional loss, the potential for development of new medicines, foods, and jobs is also lost. Biodiversity is required for a healthy and sustainable earth.'
Want to know more?
Parkinson's website: http://biology.ucf.edu/~clp
Christopher L. Parkinson, cparkins@ucf.edu
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