AP BIOLOGY

Detailed explanation-1: -The extraterrestrial or panspermia theories suggest that life existed in outer space and was transported by meteorites, asteroids, or comets to a receptive Earth. In this case the origin of life is not related to environments possible on the early Earth.

Detailed explanation-2: -The idea that life can be distributed throughout the universe, from planet to planet, is called panspermia. Some lifeforms, particularly the extremophiles, are hardy enough to survive the extreme conditions of space. Meteorites and comets are the most discussed methods for transportation, and the story is fascinating.

Detailed explanation-3: -There are three types of panspermia theories named lithopanspermia, ballistic panspermia, and directed panspermia.

Detailed explanation-4: -The term panspermia comes from the Ancient Greek ‘pan’ meaning all and ‘sperma’ meaning seed. This hypothesis links life on Earth with potential life in other parts of the solar system and Universe, but the form of that linkage is a subject of disagreement.