Has the Declaration of Independence been defaced? Experts with the National Archives who have carefully scrutinized it believe the answer is yes. Sometime between 1903 and 1940, officials with access to the Declaration marred the treasured document, rewriting or overwriting famous signatures and leaving behind the left handprint, the experts believe. The two scholars contend that it was also during this period that the handwriting on the declaration was mysteriously diminished, costing it more of its already-dwindling original ink.

Rodents were food in part of Europe

The European palate may not always have been so sophisticated. Researchers have reported evidence of Europeans snacking on rodents at least 5,000 years ago. The discovery suggests rodents such as mice and voles have not always been mere pests: They may have been a food source as well. The new finding was made after researchers sifted through nearly 60,000 small mammal bones collected in Scotland.

Planet Nine might tilt our solar system

Most people think the eight planets in our solar system orbit the sun along a straight plane, like a disc on a record player. But actually, that plane is slightly tilted, and now astronomers think they know why: the elusive Planet Nine. Growing evidence suggests that there may be a massive planet beyond Neptune, about 10 times the mass of Earth and, at the farthest point in its orbit, about 155 billion miles away from the sun. At that size and distance, astronomers concluded, such a planet might have tugged the other planets off the expected plane.

Origins of European bison uncovered

Scientists say they have unlocked the evolutionary origins of the European bison, also known as wisent. Using DNA analysis and radiometric dating, scientists were able to elucidate the complicated family tree of the big bovines, which are the result of interbreeding between ancient cattle (called aurochs) and the gargantuan steppe bison. This helps answer why ancient humans painted two distinct types of bison on the walls of caves. Stone Age hunters were painting long-horned steppe bison and an early, short-horned form of wisent.