for National Geographic News
Bryan Grieg Fry spends his life getting up close and personal with creatures most people would do anything to avoid. But his work has also uncovered why so many of the world's most poisonous snakes ended up in Australia, how they are continuously adapting to remain highly effective killersand how the chemistry they have mastered may be used to advance human health.
A childhood fascination with snakes developed into professional research for Fry. Now he is deputy director of the Australian Venom Research Unit, based at the University of Melbourne's medical school in the state of Victoria.
His specialty is researching the evolution of snake venomwork that allows him to spend large amounts of time on Australia's Great Barrier Reef investigating sea snakes or walking in the bush in search of their terrestrial cousins.
Snakes are believed to have colonized Australia between 15 and 20 million years ago, possibly from a single ancestral species. Over the millennia they diversified, adapting to Australia's multiplicity of habitats and abundant variety of food.
But it is the potency and diversity of Australia's poisonous snakes that make scientists the most excited. Seventeen of the world's most lethal snakes are found in Australia. Researchers are deciphering their chemical secrets, developed over millions of yearsand in the process finding powerful new agents to fight disease.
Australia's snakes "hit a biological lottery and ended up incredibly different and toxic,'' Fry said. "Australian mammals aren't exactly a pushover.''
Presented with a huge variety of rodents, lizards, and small mammals to feed on, Australia's land snakes evolved different sorts of venoms to target different prey animals.
"The specialization that occurred has been fantastic,'' Fry said. "In sea snakes, the venom has become more streamlined because they're feeding on just one animalfish.''
Venomous snakes have been slithering around Earth for more than 150 million years. Snakes were initially heavily muscled, swamp-based creatures much like today's anacondas of South America. But their bulk slowed them down. If they were going to catch new prey they needed to change.
Venom allowed snakes to "trade in" muscles and become leaner, faster, and more deadly.
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