Panspermia is the speculative notion that life may spread around the universe via drifting seeds or spores that provide a starting-point for Evolution on planets. The concept is ancient, dating back to Anaxagoras (circa 500 BCE-428 BCE), but was revived by such scientists as Hermann von Helmholtz (1821-1894) and Svante Arrhenius (1859-1927), winner of the 1903 Nobel Prize for chemistry. Panspermia has been seriously elaborated upon by Fred Hoyle and Chandra Wickramasinghe (1939- ) in Lifecloud: The Origin of Life in the Universe (1979), Diseases from Space (1979) and further nonfiction works developing the theory. In sf, the notion has often been adopted or implied as a convenient if not entirely plausible explanation for a multiplicity of closely humanoid Aliens scattered across the galaxy, as in Star Trek – a point made explicit in the Star Trek: The Next Generation episode "The Chase" (1993). E E Smith indicates in Triplanetary (January-April 1934 Amazing; exp rev 1948) that the two galaxies of the Lensman series were seeded by the benevolent and once-humanoid Arisians, though Smith nods to the actuality of Evolution by making some of the resulting intelligent species far from human.
P Schuyler Miller has Earth infested with alien spores in "The Arrhenius Horror" (September 1931 Amazing) and "Spawn" (August 1939 Weird Tales). Anne McCaffrey's Dragonflight (fixup 1968) invokes Arrhenius by name in connection with the ravening off-planet spores which regularly menace the titular planet of her Pern sequence. The inimical space pods of Jack Finney's The Body Snatchers (10-24 December 1954 Collier's Weekly; 1955; vt Invasion of the Body Snatchers 1973; rev 1978) are vaguely identified with panspermia vectors – at some considerable cost of credibility, especially when (finding Earth a tougher proposition than expected), these metre-long pods levitate en masse into space to drift somewhere else. The deliberately manufactured and broadcast space-spores of alien intelligences in Theodore Sturgeon's The Cosmic Rape (August 1958 Galaxy as "To Marry Medusa"; exp 1958) and Keith Laumer's The House in November (October-December 1969 If as "The Seeds of Gonyl"; 1970) are also larger than Arrhenius's motes – "like a boiled raisin" and "football-sized" respectively – but similarly embody the concept of artificial or directed panspermia. This, with humanity as the originator, is Satirized in Kurt Vonnegut Jr's "The Big Space Fuck" (in Again, Dangerous Visions, anth 1972, ed Harlan Ellison). Various sf diseases from space, such as in Michael Crichton's The Andromeda Strain (1969), may be associated with panspermia. The theory is discussed as a possibility in Eight Keys to Eden (1960) by Mark Clifton and is an accepted part of the background in Larry Niven's and Jerry Pournelle's The Gripping Hand (1993; vt The Moat Around Murcheson's Eye 1993). Another example of the common trope of a galaxy or galaxies seeded with life by ancient Forerunners is Tom Flynn's Galactic Rapture sequence opening with Galactic Rapture (2000).
Spore (2008) is a Videogame entertainingly based on the panspermia premise. [DRL]
see also: Uplift.
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