A hypothetical question about speciation

Junghalli · Post by **Junghalli** » 2005-06-20 05:24pm

Say that for some reason somebody transplanted a few primitive humans onto another planet at around the end of the last ice age. Given that they have been placed in an alien environment (albeit not too different from Earth, otherwise they'd just die) what would you say the odds are that they'd have become a different species or subspecies by now? Remember, all their history us Earth humans have only gradually been clawing our way up from stone age, so they're completely isolated genetically.

Admiral Valdemar · Post by **Admiral Valdemar** » 2005-06-20 05:33pm

This is too vague a question to answer in this form. Are there other species similar to those of Earth back in that time period or are they all new? Since speciation is a product of natural selection, the selective pressures involved would play a key role in moulding what these primates would turn into, if indeed they ever evolved to become like us or simply went extinct.

Junghalli · Post by **Junghalli** » 2005-06-20 05:45pm

Admiral Valdemar wrote:This is too vague a question to answer in this form. Are there other species similar to those of Earth back in that time period or are they all new? Since speciation is a product of natural selection, the selective pressures involved would play a key role in moulding what these primates would turn into, if indeed they ever evolved to become like us or simply went extinct.

This was a question for my own SF universe, the aliens took a couple of hundred thousand humans off ice age Earth and scattered them over several hundred planets. That's why I made it kind of vague.
OK, I'll give you one example. Say the planet in question is drier than Earth, with the land area being mostly desert. The planet is somewhat smaller than Earth, lighter gravity and thinner atmosphere. It orbits a binary pair of F-class stars, so the sunlight is brighter and there's more UV. The atmosphere has a lower oxygen content, but enough for humans to survive. The founding human population was say 500 people, with 10,000 years to multiply. They had a stone age technology when being dropped off, they may or may not have advanced since.
Under these conditions would you expect a speciation to have occured in 10 millenia?

Lord of the Abyss · Post by **Lord of the Abyss** » 2005-06-21 12:04am

10,000 years is pretty short in evolutionary terms.

If you want them to be a new species,you should either specify more time or a little genetic tampering.

dworkin · Post by **dworkin** » 2005-06-21 12:22am

They're still modern humans and the time's too short. Most of the reproductive barriers will be behaviourable. As evidence I give the Australian Aborigines (isolated 40 KYA) and Amerinds (20 KYA).

10 KY is no time at all.

You'ld be better off with Homo sapiens neanderthalis being transplanted. But even there I'ld suspect interbreeding with regular H. sapiens sapiens to be possiable, just not desirable due to different behaviours.
Unless of course, they were a truly separate species. But even then I'ld say it fails at the gamete level, not with the plumbing.