for National Geographic News
Budding engineers often take apart common devices, such as toasters, and put them back together again to learn how the parts make up a working system.
But budding biologists have a harder time using this approach—once a living organism is taken apart it usually can't be made to function again.
Now, using modern genetic engineering techniques, researchers are able to turn biological components on and off, in effect removing parts to see how each one affects the whole system.
"The more things you take apart, the more intuition you gain about the natural world," said Michael Dickinson, a professor of bioengineering and biology at the California Institute of Technology in Pasadena.
Dickinson studies fruit flies and how certain cells in their brains contribute to their ability to make rapid mid-air turns.
The work, he says, has broader implications for understanding the complexities of the natural world.
"In the end, you learn more than just how flies work," he said. "In figuring out how something as complex as a fly is put together, you gain insight into many complicated processes."
(Read a related National Geographic magazine feature on limb evolution.)
Turn on a Dime
The fruit fly is among the most studied organisms in the world, because its genes can be easily examined and manipulated to simulate human genetics.
With so much knowledge available on individual aspects of the fruit fly, scientists can now embark on answering more complex questions, Dickinson says.
The biologist has recently focused on the interacting mechanisms that permit the flies to make split-second 90-degree turns called saccades.
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