0
$\begingroup$

Will it be logically possible for genome studies to reconstitute the genomes of our local human populations as they were 2000 and 4000 years ago? What is the mathematical precision and science for that kind of thing?

I am fascinated by human facial features and i wonder what our archaic tribes looked like regionally when they were isolated, a few thousand years ago, before mixing into the melting pot that they are today.

If we can one day image facial construction from DNA using some thousands of facial genes, it will be cool if we can also find what local dna pools were like precisely a few hundred generations ago. Is it possible?

$\endgroup$
  • 1
    $\begingroup$ Thrilling thought. May already possible. 4000 year old specimen can still be fine for sequencing. en.m.wikipedia.org/wiki/Ancient_DNA and faces can already be partially reconstructed from DNA sequences newscientist.com/article/… $\endgroup$ – tsttst Jul 29 '16 at 4:09
  • $\begingroup$ Are you asking about genomes from individual people 2000-4000 years ago, or population structures? Full genomes have been sequenced from a number of individuals in that time range, but understanding population-level genomic information is a very different task $\endgroup$ – iayork Jul 29 '16 at 14:30
  • $\begingroup$ You should not believe that many human populations lived in isolation for long times. Almost all human populations had massive gene flow with many other human populations. Human history basically is a history of migration after migration after migration. Humans have always been genetically heterogeneous (rather than previously homogeneous and then faced a 'melting pot' that caused heterogeneity). $\endgroup$ – AlexDeLarge Jul 29 '16 at 19:41
  • $\begingroup$ You should not believe that many human populations lived in isolation for long times An Aboriginal Australian Genome Reveals Separate Human Dispersals into Asia says "We show that Aboriginal Australians are descendants of an early human dispersal into eastern Asia, possibly 62,000 to 75,000 years ago. ... Our findings support the hypothesis that present-day Aboriginal Australians descend from the earliest humans to occupy Australia, likely representing one of the oldest continuous populations outside Africa." $\endgroup$ – iayork Jul 30 '16 at 12:21
1
$\begingroup$

The answer is basically 'No.'.

Too much mixing has happened since then. Fortunately, in most of the world we had scientists 2000 years ago describing facial features, and in part of the world (i.e. China) we had scientists describing facial features 4000 years ago.

We do occasionally recover viable DNA samples from both 2000 and 4000 year old corpses, also actual corpses that still retain significant vestiges of their facial features, but expecting to recover even general facial features over hundreds of generations from present DNA is quite frankly unrealistic.

The good news is that human facial features aren't actually super variable; humans are just super good at spotting small differences (which comes with the territory as social animals). The bad news is that as a modern reader of latin or chinese texts on phylogeny (if you can find them, which I won't guarantee) the subtle differences in what they mean when they describe a nose as, let's say hooked, will probably be lost on you, or me, or any of us.

Your best chance is probably sequencing corpses from the relevant era and matching them up with phylogenisists' descriptions to form an idea of what they were talking about; and you might end up with a general sense of what people looked like.

I expect it will lead to severely underwhelming results, but I suppose it's worth a shot.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.