Red and green aphids get their different colors by producing carotenoids, or color compounds. Courtesy of Charles Hedgcock, R.B.P. hide caption

itoggle caption Courtesy of Charles Hedgcock, R.B.P.

Researchers Evgenia Ilyinskaya and Asgerdur Sigurdardottir sweep up volcanic ash from a small bridge just south of the Eyjafjallajokull volcano. The ash will be taken back to the University of Iceland for analysis. Joe Palca/NPR hide caption

itoggle caption Joe Palca/NPR

Even the spin of a seemingly random roulette wheel can be predicted if you have the right information, says Antonio Acin of the Institute of Photonic Sciences in Barcelona. hide caption

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An actor prepares to receive "shocks" from the audience on a fake TV game show, staged for a French documentary. Psychologists have questioned the ethics of such experiments because of possible mental trauma suffered by participants. Christophe Russeil, HO/AP hide caption

itoggle caption Christophe Russeil, HO/AP

DNA analysis showed that most dogs share genetic markers with Middle Eastern gray wolves, like this one photographed in Israel. Courtesy of Nadav Perez hide caption

itoggle caption Courtesy of Nadav Perez

Researchers were able to correctly match bacterial DNA on keyboards and computer mice with their individual users. This bacterial "fingerprint" could become a new forensic tool, though it's not yet ready for the courtroom. hide caption

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A genetic abnormality causes this chicken to exhibit both male and female characteristics. The right (white) side is typical of males and the left (brown) side is typical of females. The Roslin Institute at the University of Edinburgh hide caption

itoggle caption The Roslin Institute at the University of Edinburgh

Chameleons, such as this Chamaeleo calyptratus, feed by way of ballistic tongue projection, which launches their tongues at prey with a rapid burst of speed. Cold temperatures do not slow their tongues down, allowing chameleons to catch meals even when the temperature drops. Courtesy of Christopher V. Anderson hide caption

itoggle caption Courtesy of Christopher V. Anderson

A technician at pharmaceutical company pursuing new gene therapy treatments collects re-engineered viruses, called "vectors." Viruses, stripped of their virulence and ability to replicate, are the most common delivery vehicles for healthy DNA. Paul Sakuma/AP hide caption

itoggle caption Paul Sakuma/AP