After 16 days, the partial shutdown of the U.S. government has ended . Although lawmakers on both sides of the aisle cited research concerns  in the debate to end the shutdown, only one out of 22 Republicans on the House of Representatives science committee  actually supported the budget deal. Now, scientists are trickling back into work , and federal agencies are open for business —although some are asking for a bit of breathing room  as they get caught up. Follow all of our shutdown coverage here .
Scientists have long argued about why we devote roughly a third of our lives to sleep, but with little concrete data to support any particular hypothesis. Now, scientists might have finally figured out the basic purpose of sleep: It clears the brain of toxins. The discovery might explain why neurological diseases such as Alzheimer’s are associated with a lack of sleep. So don’t feel guilty next time you need a nap—your brain just needs a wash.
Researchers have uncovered an iconic new fossil—an amazingly complete 1.8-million-year-old hominin skull, found in Dmanisi, Georgia. Combined with four skulls found earlier at Dmanisi, the fossil challenges researchers' views of human origins.
Cone-shaped, mineralized structures that surrounded the mouths of ancient eel-like creatures called conodonts and helped them grasp and mince their food weren’t teeth at all, according to a new study. The findings suggest that one theory of how teeth first appeared in creatures with backbones—including humans—needs to be abandoned entirely.