
Urbanisation signal detected in evolution, study shows - funkylexoo
http://www.bbc.co.uk/news/science-environment-38519299
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drallison
The full paper
([http://www.pnas.org/content/early/2017/01/01/1606034114.full...](http://www.pnas.org/content/early/2017/01/01/1606034114.full.pdf))
is an interesting read. This study shows that evolutionary adaption to
urbanization is significant and observable.

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hacker_9
Interesting study, but I hate the way they've framed it as if this is 'new'
information. Of course urbanisation affects living things; you are literally
changing the ground beneath their feet, the air they breath etc. Did people
not expect adaptable organisms to.. adapt?

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gwern
People are always saying that humans can't be evolving because 'evolution
doesn't work that fast'; by the same token, plants/animals can't be evolving
_that_ fast either because their generation times typically aren't more than a
factor faster (and sometimes can be slower - think trees). So for me the
interest is definitely, if all these plants and animals are so visibly
evolving for urban environments which have only become predominant very
recently even by human standards, how have humans been affected? We already
know that humans have evolved smoke-tolerance to cope with the health effects
of fire, but what else for cities? More intelligence, extraversion, parasite
resistance?

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skadamou
I think the difference between plants/animals and humans might be tied to
mortality rates. I would imagine that urbanization has a very adverse effect
on most plant and animal species and that only a small minority of individuals
survive the initial shock of urbanization. Those that do survive will pass on
the traits that allowed them to flourish in their new environment and such
traits will quickly dominate the post-urbanization populations of these plants
and animals since they are necessary for their survival. Humans are different
in that urbanization appears to make survival (and mating?) easier for a
majority of the population and thus there are not such strong selective
effects.

Note: I am not a genetic biologist, this is just conjecture

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rdiddly
You've got the right idea. Think of any urban center as the site of a
localized mass extinction, and you're even closer. Evolution doesn't always
happen slowly. In a mass extinction event it happens quickly.

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Almaviva
Now consider that in human history, about 40% of men were able to breed. So
30% of the population goes extinct every generation without passing on genes,
assuming all women reproduce. So with a few hundred iterations of this kind of
70:30 split, you could see how evolution could happen quite quickly even under
normal circumstances.

