Astronomy 1021 Lecture Notes - Lecture 19: Interstellar Travel, Astrobiology, Volcanism

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Chris Racknor

Document Summary

The scieniic study for life in the universe is called astrobiology. Evidence indicates that life arose early in earth"s history, ofering at least a hint that life might also arise with similar ease on other earth-like worlds. Fossil evidence suggests that life on earth was thriving 3. 5 billion years ago. Carbon isotope evidence suggests that life was present on earth at least 3. 85 billion years ago, which may be almost as early as it was possible for life to take hold. Fossil records show how life has changed through ime, and the theory of evoluion explains how these changes have occurred. Darwin"s two undeniable facts and inescapable conclusion: overproducion and compeing for survival, individual variaion, unequal reproducive success (natural selecion) The theory of evoluion is backed by a tremendous body of evidence, and there is no more scieniic doubt about evoluion than there is about gravity or atoms.