These questions could, in principle, be addressed with ancient DNA analysis — if samples were available.

For Buckeye Knoll, they are not.

For Bering Sinkhole, the question remains open.

What The Edwards Plateau Looked Like In The Early Holocene

Eight thousand years ago, the Edwards Plateau would have looked different from the landscape visible today, though the differences might be subtle to a casual visitor.

The limestone bedrock was the same — the same ancient seafloor deposits, the same karst topography with its sinkholes and caves and springs.

The rivers were running in roughly the same channels, though their flow regimes may have differed from today’s patterns.