A University of British Columbia researcher has discovered dozens of species of jumping spiders that are new to science, giving scientists a peek into a section of the evolutionary tree previously thought to be sparse.
Jumping spiders are found in every part of the world except Antarctica. Capable of jumping 30 times their body length, some of the 5,000 documented species are common in households. They come in many shapes and sizes, some resembling ants or beetles.
"Instead of sitting at the centre of a web, jumping spiders found a new way to make a living by wandering around their habitat and pouncing – like cats – on their prey," says Wayne Maddison, a professor of zoology and botany and director of the Beaty Biodiversity Museum at UBC.
Two of the jumping spiders' eight eyes have evolved to be large with high-resolution vision to spot prey. Female jumping spiders also use this heightened visual sense to watch males, who show off their colourful bodies during courtship dances.
Maddison collected more than 500 individual spiders during an expedition with Conservation International (CI) last summer in the Kaijende Uplands, one of Papua New Guinea's largest undeveloped areas. Preliminary studies show as many as 130 species, including 30 to 50 never-before-identified species, may have been found on the trip.
Some of the species discovered are highly distinctive, occupying "lonely" branches on the evolutionary tree of jumping spiders. Further research on these new specimens will shed light on how jumping spiders evolved their unique features – a question that continues to puzzle scientists. "Our finding shows that the great age of discovery isn't over by far," says Maddison, who estimates there may be at least 5,000 more species of unidentified jumping spiders in the world.
The CI expedition also identified two new plants, three frogs and a gecko that are believed to be new to science. Maddison says the smaller animals — like insects and spiders — and plants may hold the secret to many of the world's unknown chemicals.
"Spider venom has evolved for millions of years to affect the neurological systems of the spider's insect prey, and each species of spider gives us another opportunity to find medically useful chemicals," says Maddison. "Jumping spiders with their remarkably miniaturized yet acute eyes could help us understand how to push the limits of vision. In addition to filling in the gaps in our planet's natural history, exploring spider biodiversity and evolution could potentially inform fields as diverse as medicine and robotics."
"More than anything else, it's an amazingly beautiful world and we're simply trying to reveal it," says Maddison, who will be sharing his experience on the expedition during an April 16 public lecture hosted by the Beaty Biodiversity Museum. "There is a whole lot of beauty in these small spiders if we look closely enough."