Comment by graemep
6 hours ago
If whole populations were wiped out and the world was repopulated by a small remnant would that not account for it? Or if an extinct human species had an advanced civilisation?
6 hours ago
If whole populations were wiped out and the world was repopulated by a small remnant would that not account for it? Or if an extinct human species had an advanced civilisation?
The founder effect differs between small populations filtered from a large population vs a smaller parent population.
I want to point out that the silurian hypothesis is specifically about civilizations removed from us by geologic time. Advanced human precursor civilizations are much more effectively ruled out by the current evidence. Basically, a hypothetical precursor society either has to look very different from any we know about and materialize out of nowhere like alien colonists, or they didn't exist.
For example, we know they weren't using large amounts of fire because nothing in the global charcoal records points to that. We know they weren't using plants that produce pollen because we don't find phytoliths with domestication indicators. We know they weren't using surface metals, because there was lots of that still around when the classically ancient civilizations started. We know they didn't contribute significantly to the gene pool. We have no material culture from them. We don't have a location on Earth they would have lived in. Etc.
There’s always the hollow earth!
My thoughts:
Civilisation implies large scale agriculture.
Large scale agriculture implies specific pollen signatures.
We don't see any of these signatures in the pollen records dredged up from lakes and seas.
There was no previous civilisation in the last 1.4m years (this is the depth of the pollen records we have I think).
Or it stayed concentrated for a long time until local conditions forced a scattering.
No. That’s exactly how we know.