Archaeology relies on fragments and hints and nuances we lump into the category of ‘data’ in order to create narratives of how life and the planet intersected in the past.
A computer model built by researchers at the Institute of Planetary Research in Berlin is pushing the gaze back substantially farther than an archaeologist can, though, to produce results that are speculative and striking.*
The model runs a ‘dead-Earth’ hypothetical context in which life – algae, lichen, and bacteria in the early case – never formed. In a ‘live-Earth’ setting, the life that became us does germinate. All goes identically in the models when they start 4 billion years ago; by 2.5 billion years ago the early continental plates rise above the ocean in both cases. This is where things get really interesting.
In the live-Earth model the life forms ‘colonise the new land, erode it and dump masses of sediment into the ocean’ where it is subducted and then ejected to the surface in volcanic eruptions. The live-Earth becomes the one we know with roughly 40% of the planet covered in continental land.
A great deal of environmental literature speaks of a hypothetical pristine Nature that never actually existed. What makes the results of the 'live-earth' model so fascinating is the concept that even the deepest, most inner core of the Earth potentially co-evolved with the life that the planet supports, ourselves being part of that life. We are all tangled, in essence, into a matrix that includes stone, water, plant, animal, and human to form a particularly Earthly amalgam. Geosphere and biosphere unite in the messy time of the Anthropocene.
*A hat tip to Chris Rowan @Allochthonous , whose tweet alerted me to this article I might have otherwise missed. If you don't read his blog, Highly Allochthonous, it's worth doing.