Emily Hasler, an English Heritage employee at Charles Darwin's home, Down House, cleans a rabbit bone in his old study on April 2, 2011 in Downe, England. Staff at the house are cleaning and preparing the property ahead of their peak visitor season. The house contains the study where Darwin wrote “On the Origin of Species”, as well as family rooms and an extensive garden that inspired the renowned scientist. (Photo by Oli Scarff/Getty Images)

Baraa Melhem plays on her sisters bike at her mothers house on February 2, 2012 in Qalandia, near Ramallah, West Bank. Baraa Melhem was held in captivity in a bathroom by her father for over nine years, and was finally rescued by Palestinian security forces after a family member notified police. (Photo by Ilia Yefimovich/Getty Images)

Casey Stoner of Australia and Repsol Honda Team rounds the bend during the third day of MotoGP testing at Sepang Circuit on February 2, 2012 in Kuala Lumpur, Malaysia. (Photo by Mirco Lazzari gp/Getty Images)

Models showcase Valentine's Day underwear celebrating the results of a recent survey revealing that men find the lingerie, boxer shorts and vests, the biggest turn on ahead of February 14 Valentine celebrations, at Waterloo on February 2, 2006 in London, England. (Photo by Gareth Cattermole/Getty Images)

Rival supporters taunt each other after the FA Cup Third Round match between Manchester City and Manchester United at the Etihad Stadium on January 8, 2012 in Manchester, England. Localised clashes and stone throwing between fans took place on the streets after Manchester United beat Manchester City 3–2. (Photo by Christopher Furlong/Getty Images)

The “Strandbeest” sculpture created by Dutch artist Theo Jansen walks at Federation Square on February 1, 2012 in Melbourne, Australia. The 12 metre long, 4 metre high and 2 metre wide structure built of plastic tubes and bottles designed to walk using wind energy will be on display at Federation Square until February 26. (Photo by Scott Barbour/Getty Images)

A Dalek, a Cyberman and a Silence invade the Melbourne Cricket Ground on February 2, 2012 in Melbourne, Australia. The Doctor Who Daleks this weekend are performing for the first time outside of the UK with the Melbourne Syphony Orchestra at Plenary Hall. (Photo by Scott Barbour/Getty Images for BBC Worldwide)

Groundhog handler Ron Ploucha holds Punxsutawney Phil after he saw his shadow predicting 6 more weeks of winter during the 126th annual Groundhog Day festivities on February 2, 2012 in Punxsutawney, Pennsylvania. (Photo by Jeff Swensen/Getty Images)