I recently discussed this in my blog. Here is a quote:
The Buddha proceeds to tell Vasettha a cosmogony, a myth about the
origin of the world and life. The earth was originally entirely
covered by water, and everything was blinding darkness. There were no
sun, moon, stars, night, day, months, fortnights, years, seasons, or
gender. Interestingly, scientists believe that the earth was
originally a “waterworld,” almost entirely covered by water, about 2.5
billion years ago. The only life on earth at that time was sexless
algae and bacteria. After a very long period, a skin formed on the
surface of the water like the skin that forms over hot milk as it
cools. In this passage, the Buddha demonstrates that he understands
that the cause of the one world ocean at that time was the deep mantle
of the earth, which was 200 degrees hotter than it is now, and also
that it was cooling. As the deep mantle cooled, the continental crust
formed must have been as described in the sutta.
During the waterworld era, any oxygen produced by photosynthesising
bacteria would have been quickly used up through reactions with
decaying organic matter in the oceans.
When the newly emerged land eroded, it produced sediment that washed
into the oceans and buried the organic matter, preventing further
reactions with oxygen, the scientists believe. As a result, oxygen was
allowed to build up in the atmosphere and enable oxygen-breathing life
to evolve and flourish.
The eroded sediment would also have fertilised the oceans with
phosphorous, an important nutrient for living things.
The Pali Canon calls this phosphorus “skin” rasa-pathavi (lit.
‘earth-sap’). Interestingly in view of the subsequent reference to
luminance, phosphorus emits a faint glow when exposed to oxygen. It is
also an essential element of the human genetic material, DNA and RNA.