What was young earth like? What forces operated, what materials existed, and what combination of these provided the initiation of replication?
The thought struck me recently upon viewing a documentary about the moon and its influence on earth. The documentary described the young earth as a violently volcanic sphere in a desparate tug of war with the young moon. At the time, of course, the moon was closer to earth than it is now- the early stages of spiral extraction from earth's gravitational grip.
The moon had an influence of its own. Its tug on the earth, being as close as it was, was considerably greater than today and thus the tidal forces were much more extreme. Come to find out, there is a great deal of interest in the moon among those arguing for and against Intelligent Design.
Add these components together and we may hypothesize a young earth that was extremely energetic. There was little or no atmosphere to diffuse the intense solar radiation of a relatively young sun. There was the compression of matter still settling inward from earths original creation and its concurrent release of heat. There was the moons tug.
Extreme radiation from above. Extreme heat from beneath. And extremely high levels of dissolved minerals.
Is this where life first made entrance? What clues exist today that support the notion that life emerged in this hostile place? Why would the evolution of a mutualism be postulated as an important characteristic of young earth?
I have always been intrigued with extremophiles. Life's origin was at one time thought to have come about in a calm cesspool of delicate embrace. I find this concept absurd. Young earth was anything but delicate by our most contemporary assessments. We are finding more about this as we continue our pursuit of the mysteries of deep space. The youngest of material spheres seem to have this extreme component in common.
Biological Oceanography of Young Earth
Can we hypothesize that the young earth plausibly consisted of hydrologic characteristics that resembled hydrothermal vents, mid-ocean ridges, commonly around the sphere? And can we not also assume that a minimal atmosphere probably allowed a much higher intensity solar radiation to young earth's surface? Add now to these assumptions the following: that a more closely positioned moon had a greater gravitational effect on the ancient oceans?
Now imagine the collision of land and sea. Did that interface have the most opportunity to spawn the first replicating molecule? Would these fantastic energetic inputs not have a tremendous increase in the kinetics of the entire young earth system? Would this not also have a combined effect of adding the minerals of shallow seas, volcanic rifts and associated matter (H2S-based reductive environment), and UV radiation for good measure? Add to all of this a tidal force that acted to slosh around this chemical cocktail of briny nutrient. Such an assemblage would have made the spontaneity of a nucleoside more likely, would it not?
Nitrogen was plentiful, as it is today. Hydrogen, hah! More than enough to go around. But where was the oxygen?? This was an anaerobic young earth, O2 was lacking. We can't have DNA without it. What we would more plausibly have would have been akin to RNA genesis. Whatever the replicating molecule was at the time, it could have easily formed given the kinetics of this open system. And if this hypothesis of the young earth environment is anything close to being true, I would not be surprised to find the beginning of life itself. Perhaps, something even more primitive than stromatolites?
Mimicry is one clear example of natural selection . Animals of all types fit in by camouflage. These maskings serve to trick predators and thus would appear to provide enhanced fitness. In the oceans, bioluminescence is often used as a means of fitting in with animals as they ascend at night to feed in the shallows. The moonlight from above is matched by the luminescent bacteria housed in tissues of a variety of pelagic invertebrates.
