The chief theme of this myth is the separation, usually of the sky from the Earth. This story is found in a band stretching from New Zealand to Greece ... and it invariably has a small number of common features. The first is the appearance of light. As it says in Genesis, 1:3: 'And God said, let there be light: and there was light.' Nearly all cosmogonies have this theme, where it is notable that neither the sun nor the moon is the source of the first light at Creation. Rather, the first light is associated with the separation of heaven and Earth. Only after heaven and Earth have separated does the sun appear. In some traditions in the east the light is let in because the heavy substance of the clouds that envelop the Earth sinks down to the ground, and the light, clearing the clouds, rises to become heaven. (pp. 23-24).What might account for the wide geographical distribution of this particular myth? Watson's suggestion is that myths of watery creation represent collective memories of the eruption of the Toba supervolcano about 71-74,000 years ago, just as the first human beings were arriving in South Asia. This was probably the most powerful volcanic eruption in the planet in the last two million years, and it precipitated a global volcanic winter for years, including a prolonged period (at least several months) of complete darkness in some areas. The eruption nearly wiped out the human race; various estimates suggest that the total human population on Earth declined to perhaps 3,000-10,000 individuals afterwards, though of course all such numbers are highly uncertain. (We live, still, "by geological consent, subject to change without notice;" but that consent was nearly withdrawn then). And the myths of watery creation provide a fairly good description of how the aftermath of the eruption would have been experienced:
The 'separation' myth is a not-inaccurate description of what would have happened over large areas of the globe, in South East Asia, after the Toba eruption and the volcanic winter that would have followed ... Sunlight would have been cut out, the darkness would have been "thick" with ash, the ash would gradually have sunk to the ground, and, after a long, long time, the sky would gradually have got brighter, lighter and clearer, but there would have been no sun or moon visible perhaps for generations. There would have been light but no sun, not for years, not until a magical day when, finally, the sun at last became visible. We take the sun for granted but for early humankind it (and the moon, eventually) would have been a new entity in the ever-lightening sky. Mythologically, it makes sense for this event to be regarded as the beginning of time. (p. 25)The sun was once new.
The book is full of much other interesting but sometimes hard to assess speculation about human prehistory, including fascinating pages about flood myths (the most common of all myths; as a Platonist, I am reminded of these passages), which appear to represent collective memories of enormous floods 14,000, 11,000 and especially 8,000 years ago caused by the melting of gigantic ice sheets. (The story is a bit complicated, but apparently 8,000 years ago the Laurentide ice sheet started to melt in such a way that the water was "dammed" by an ice plug at the Hudson Strait. When the plug broke under the pressure of the meltwater, sea level would have increased by "20-40 centimeters" more or less instantaneously, according to Watson, and the shift in the distribution of such a huge mass of water would have triggered gigantic earthquakes and tsunamis as the crust of the Earth essentially "bounced"). There are also discussions of the connections between the domestication of dogs and the discovery of fathers (it is not altogether clear that the link between males and conception was made until it was observed in dogs, which have a much shorter gestation period than women; we might say that dogs, in a sense, created the idea of fatherhood), of the different rhythms of root agriculture (common in the Americas) vs. cereal agriculture, and many other things. Perhaps the oddest claim is the idea that a number of important differences in "religious" practice between the New World and the Old before 1492 can be traced to the fact that more than 85% of all known psychoactive plants on Earth are found in the Americas. (When read in context and tied to a number of other differences between the old world and the new, the claim makes a great deal of sense, but the jokes about stoned Americans write themselves).