(Inside Science) -- Americans may be recreating the cradle of humanity with their thermostats. When researchers compared temperature and air moisture levels in 37 U.S. homes to outdoor climates around the world, they found that all but three of the homes were most similar to locations in Africa -- the same continent where the first humans arose hundreds of thousands of years ago.The researchers weren't even trying to study human evolution, said Michael Just, an applied ecologist at North Carolina State University in Raleigh and first author of the study.