[yarg]

Just once for the initial self-replicators would be my guess.

Not in a cell, but in porous rock around the hydrothermal vents (at the bottom of the ocean).

Given the exponentialish 'population' growth of chemical soup, coupled with the fact that the very low likelyhood of a localised self-replicator forming, by the time second place came about the game would already be over.

Far more likely is preserved 'mutations' to chemical replicators leading to divergent forms of demi-life.

[Retric]

> by the time second place came about the game would already be over.

That’s presumably true, but it means there could have been a very large number of losers not just 1. Aka if extremely primitive life showed up once on earth then it might be a rare event, if it happened 100 trillion times then most planets with the right conditions will have some form of life.

[yarg]

It'll be a Poisson distribution.

If the spread is too wide then the chance of spatiotemporally cohabiting civilizations of distinct origins will be diminishingly small.

But I don't actually think that the planetary parameters that allow for replication are (in any way) specific to earth.