This excerpt supports my idea of a hot earth at the origin.
BioScience, June 1993 v43 n6 p390(4)
Did surface temperatures constrain microbial evolution?
David Schwartzman; Mark McMenamin; Tyler Volk.
Abstract: It is proposed that the upper temperature for
viable microbial growth corresponds to the actual surface
temperature at the time of the group's appearance. This
theory states that timing of major events in evolution may
have been influenced to a large degree by the pervading
surface temperature of the earth.......
In conclusion, the Archean was apparently much warmer than
previously assumed. If the ancient tillites are indeed
confirmed as impact deposits, a critical upper limit to
surface temperature will be eliminated for most of the rest
of Earth history. Then, the possibility arises that
temperatures were much higher for most of Earth history than
heretofore assumed. The timing of major evolutionary
innovation could then be determined by the temperature of
the surface system of Earth, itself determined by the
evolution of the biosphere, constrained by abiotic boundary
conditions (e.g., the luminosity of the sun)