From fossil and sequence evidence, we can infer that the informational molecule DNA would have been born some time in that volume, because archeobacteria
, the first forms of life, would appear in the seas in volume 22.
To answer that question, to grok our DNA, we need to go back in evolution to complex systems evolved by archeobacteria billions of years ago, when they alone held title to Earth.
The greatest steps in evolution are arguably the evolution of nucleated cells (eukaryotes) as the communal symbioses of archeobacteria (prokaryotes) and the later evolution of multi-celled creatures from these eukaryotes.
The successive discoveries of populations of organisms previously only found in hydrothermal vents, such as vestimentiferans and bivalves, in other anoxic, methane- and hydrogen sulfide-rich environments, and of populations of metabolically versatile archeobacteria
, some free-living and others in symbiosis with different animals, leads one to conclude that hydrogen sulfide-based chemosynthesis is a much more widespread basis for primary production than was thought just a few years ago, when hydrothermal oases were first discovered.