Researchers Observe Evolution Chain Reaction
News story originally written on February 5, 2009
Scientists have discovered a new species of fruit fly and wasp - the two species are related and their existence can be attributed to the introduction of apples in the United States almost 400 years ago.
For almost 250 years after the introduction of apples to North America, insects referred to as hawthorn flies, Rhagoletis pomonella, continued to meet on the small, red fruit of hawthorn trees to mate and lay eggs. Then, in the mid-1800s, some of these "hawthorn flies" began to mate and lay eggs on apples instead. The flies that were attracted to apples eventually became different, genetically, from the flies attracted to hawthorns. The wasps that live on the flies' larve also became genetically different.
"It's a nice demonstration of how the initial speciation of one organism opens up an opportunity for another species in the ecosystem to speciate in kind," said Jeff Feder, a biologist from the University of Notre Dame. "Biodiversity in essence is the source for new biodiversity."
This represents a chain reaction of biodiversity where the modification of one species triggers the sequential modification of a second, dependent species. This research is important because it provides insights into solving Darwin's mystery of the origins of new species.
"What is startling is how fast populations can ecologically adapt to new habitats and begin to evolve into different species in front of our eyes," Feder said. "Clues can be found right before us as we sit on our deck chairs barbecuing and drinking pop. All we have to do is open our eyes and we can see new life forms coming into being in that scraggly old apple tree in our backyard."