Humans & Evolution
Feb. 20th, 2007 12:47 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
sen_no_ongakuThought: in the past few thousand years, genetic evolution in humans has been largely -- though not wholly -- supplanted by technological innovation.
What sets humans apart from other animals is the ability to adapt to selection pressure on an individual rather than generational level. For example, in response to colder temperatures, rather than grow a warmer coat of fur over a thousand years of breeding, we could simply kill a creature that already has a lot of hair and wear its skin. Another example might be the invention of spectacles for people with poor vision, a trait which would otherwise be crippling in.
This is not to say that such innovation can completely replace biological adaptation. Our technology has limits -- and we can see those limits; but we can also move them. Nevertheless, we can't guarantee we can move those limits in time.
Anyway, in the absence of the environment as a driver of evolution, are there other, perhaps societal sources of selection pressure?
What sets humans apart from other animals is the ability to adapt to selection pressure on an individual rather than generational level. For example, in response to colder temperatures, rather than grow a warmer coat of fur over a thousand years of breeding, we could simply kill a creature that already has a lot of hair and wear its skin. Another example might be the invention of spectacles for people with poor vision, a trait which would otherwise be crippling in.
This is not to say that such innovation can completely replace biological adaptation. Our technology has limits -- and we can see those limits; but we can also move them. Nevertheless, we can't guarantee we can move those limits in time.
Anyway, in the absence of the environment as a driver of evolution, are there other, perhaps societal sources of selection pressure?
![[identity profile]](https://www.dreamwidth.org/img/silk/identity/openid.png){kind=small}
Good topic!
Date: 2007-02-20 07:47 pm (UTC)Has genetic evolution been supplanted by memetic evolution? With modern tech there's a very broad range of neutral (neither contributiong to nor hampering reproduction) traits. With in that range what people think and learn probably has more evolutionary weight their their physical attributes. As technology improves the physical capabilities of the individual matter less and less.
Societal pressures act as a darwinian evolutionary landscape for anything that cycles faster much than the society changes (no idea what the relative change rates would need to be, other than the landscape needs to be relatively still). Long term societies drive genetic changes to favor given phenotypes, but probably aren't stable enough and/or isolated enough to drive speciation. The isolation aspect is probably more of a factor than the time.
In a larmarckian situation adaption can take place in a single generation, or less - instead of generational changes it's a continuum of change that's independent of the carrier. Society is based on individual ideas, attitudes, knowledge, etc., all of which continuously change. Serious feedback cycles result. The stability of the societal landscape ties to how quickly and easily ideas can propogate - global networking certainly makes things interesting.
I think one of the big things that sets modern humans apart is the storage and transfer of knowledge independent of individuals.
Is being human about biology and physics or about beliefs and actions? It depends on the context of the discussion. Outside the strict realms of biology, I tend to equate 'human' with more general terms like sapient, sophont, etc.
Bruce Sterling explors this general topic in his novel Schismatrix. I highly recommend it, and can loan you a copy if you like. The Culture novels by Iain Banks are also a good exploration of this. I'd also recommend Kaleidoscope Century by John Barnes as a good (though disturbing) novel with this theme.