Despite knowing when life first appeared on Earth, scientists still do not understand how life occurred, which has important implications for the likelihood of finding life elsewhere in the universe.

A sleep study may make sense when poor sleep affects your work, relationships, activities, or quality of life. You’ll usually start with your primary doctor, then see a sleep specialist. Sleep ...

Ichthyology is the branch of zoology devoted to the study of fish, including: bony fish, Osteichthyes; cartilaginous fish, Chondrichthyes; and jawless fish, Agnatha. The discipline can include the ...