Problem is, beso... your statement concerning extremophiles is rife with contention in the scientific community, as I'm sure you're aware. That's not a problem, except that some jump to the conclusion that once more a definitive answer to the origin of life (OoL) has been discovered.
There are 4 major objections to your proposal. As I'm sure you're aware, "...geochemical evidence places the presence of life on Earth at 3.86 billion years ago. The oldest rocks date to 3.9 billion years ago. Prior to this time, Earth existed largely in a molten state, unsuitable for life..." (Source: Karl O. Stetter, et al, “The Lesson of Archaebacteria,” in Early Life on Earth: Nobel Symposium No. 84).
In a concerted effort to push the origin of life further back than the currently accepted 3.86 billions of years "...A thermophilic or hot origin of life would provide some additional time desperately needed for natural process hypotheses. Scientists from Stanford University and NASA’s Ames Center examined this possibility by estimating when (and how long), prior to 3.9 billion years ago, Earth’s surface temperature resided in the vicinity of 100 °C-the temperature thermophiles require.
The most significant event contributing to Earth’s hot, largely molten state came from the impact of an object roughly the size of Mars, just after Earth formed. When it crashed into Earth, the core of the impactor fused with Earth’s core. Lighter elements from the impact spewed into Earth’s orbit and quickly coalesced to form the moon. Immediately after this collision, Earth’s surface temperature was hot enough to vaporize silica (sand). The surface eventually cooled to temperatures conducive for liquid water..." (Source: Peter Ward and Donald Brownlee, Rare Earth: Why Complex Life is Uncommon in the Universe).
Further, "...The moon-forming impactor stands as only one of a large number of objects striking Earth between 4.5 and 3.9 billion years ago. Each collision returned Earth to high temperatures, melting rock on the surface and subsurface and elevating the surface temperature above the maximum temperature survivable by thermophiles..." (Source: B. A. Cohen et al., “Support for the Lunar Cataclysm Hypothesis from Lunar Meteorite Impact Melt Age,” Science pg. 290 (2000)). The attempt to extend the origin of life beyond 3.9 billions of years hasn't been successful yet and this is but one of four objections rooted in science.
Consult your own Prof. Andrew Watson of the University of East Anglia. He's written several good articles on the rarity of human life. (Seen here:
http://www.astrobio.n...rare-cosmic-commodity )
(Contd.)