What is the likelihood that inhabitants of an alien planet similar to Earth geologically would have races?

First off, let's get definitions out of the way:

A "race" here is defined as stable, heritable, phenotypic, clearly visual distinction between large demographic groups living in different geographic areas - but all of whom actually belong to the same biological species (e.g. can freely and effortlessly interbreed; and have fairly minimal genetic differences where you would have trouble easily distinguishing members of each "race" from genome alone).

For an apex intelligent species that lives on multiple continents of a planet that is fairly earth-like geologically and planetologically (e.g. seasons, climate variations etc.. are similar), how likely would it be that they would evolve into distinct and easily distinguishable "races", based on the current understanding of evolutionary biology?

By "How likely", I mean is it on the scale of "practically inevitable barring special circumstances, due to these and those evolutionary biology rules", or "Homo S. is this way thought pretty unlikely chain of random environmental coincidences that on average are unlikely to happen elsewhere"

Background: the question arises when creating First Contact setting, and deciding if the alien species would be utterly bewildered by the fact that some Homo S. members look to be completely different color.

An example of this would be Eric Flint's Ishtar in "Mother of Demons", where the issue was solved by the fact that the aliens were chromatophoric and thus the skin color changed for each individual based on emotions.

posted over 9 years ago

DVK‭

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