The heartbeat is synonymous with life. It's one of the first essential functions to begin during development and to end at ...

During perinatal (i.e., during prenatal and early postnatal) development, sex steroids cause permanent, hard-wired differences in the organization of central and peripheral physiology (i.e ...

Research on human tails is no recent development, though. In 1875, Darwin noted in The Descent of Man how “in certain rare and anomalous cases,” humans “form a small external rudiment of a ...

4th grade physical development guide: Find out what you need to know Here's what you should know about your fourth-grader's physical development. Updated July 28, 2020, 8:24 AM PDT Parent Toolkit ...