Archaeology is the study of the ancient and recent human past through material remains. Archaeologists study human prehistory and history, from the development of the first stone tools at Lomekwi in East Africa 3.3 million years ago up until recent decades. They analyze artifacts, architecture, biofacts or ecofacts, and other material remains to learn about the people who made and used them. Archaeologists might specialize in a particular region of the world or a specific topic of study, such as human remains (bioarchaeology), animals (zooarchaeology), ancient plants (paleoethnobotany), stone tools (lithics), or technologies that find, map, or analyze archaeological sites. Archaeology is based on the scientific method, and archaeologists ask questions, develop hypotheses, and use evidence to choose a dig site, then use scientific sampling techniques to select where on the site to dig. They observe, record, categorize, and interpret what they find, then share their results with other scientists and the public. Archaeologists also have a professional responsibility to analyze all the artifacts and information obtained, to report on their research, and to curate the collections. Archaeology is a diverse field of study, and archaeologists can work in academia, museums, or cultural heritage management, which involves preserving historic and archaeological sites during development and other projects.