Panspermia

From EvoWiki

The Panspermia or Exobiological Hypotheses hold that life originated extra-terrestrially and was brought to earth either through a “rain��? of cosmic molecules or through cometary / asteroidal collision with earth. Svante Arrhenius and William Thomson (Lord Kelvin) proposed the idea in the 19th century. Lord Kelvin used it as a part of his argument against Darwinism. The concept was proposed in the late 20th century by astronomers Fred Hoyle and Chandra Wickramasinghe. Francis Crick, in 1973, proposed his directed panspermia hypothesis which went so far as to hold that earth was “seeded��? with DNA by extra-terrestrials. In the 1990s the ALH84001 meteorite of Martian origin appeared to contain microfossils. This along with other meteorite evidence is still being debated. The strong emphasis on the search for life on Mars by NASA is evidence of the fascination the concept holds for the general public and science community.