Scientists have long linked the evolution of the human hand—unique for its lengthy opposable thumbs and dexterous fingers—to the rise of stone tools some 2.6 million years ago. These instruments, from ...

Bones form the scaffolding that hold the body together and allow it to move. They also help protect vital organs, store minerals, and provide an environment for creating bone marrow. By adulthood, ...

Flat bones are thin and flat. Sometimes they have a slight curve. Flat bones serve as a point of attachment for muscles or protection for your internal organs. Read on to learn more about specific ...