Rice, arsenic, and evolution

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Rice, arsenic, and evolution

Postby GeoffreyLevens » Thu Feb 23, 2017 9:22 am

Desert people evolve to drink water poisoned with deadly arsenic
By Ian Graber-Stiehl
PEOPLE in a south American desert have evolved to detoxify potentially deadly arsenic that laces their water supply.
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Re: Rice, arsenic, and evolution

Postby GeoffreyLevens » Thu Feb 23, 2017 10:17 am

This should help lay to rest (nail the coffin) on the Paleo idea we have not adapted to eating beans and grains. We started eating them a lot longer ago than the Atacma folks started being exposed to arsenic!
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Re: Rice, arsenic, and evolution

Postby pundit999 » Thu Feb 23, 2017 10:36 am

This is similar to the study published last year that showed that people consuming vegetration/plants only diets for 1000s of years have developed adaptations that extract omega3s more efficiently from plants:

Why is it that some people can stay healthy only by sticking to a strict vegetarian diet? Why is it that others can eat a steak a day, remain slim, avoid heart disease and feel like a million dollars? The answers may lie in your heritage.

Cornell University researchers have found a fascinating genetic variation that they said appears to have evolved in populations that favored vegetarian diets over hundreds of generations. The geography of the vegetarian allele is vast and includes people from India, Africa and parts of East Asia who are known to have green diets even today.


https://www.washingtonpost.com/news/to-your-health/wp/2016/03/30/cornell-study-finds-some-people-may-be-genetically-programmed-to-be-vegetarians/?utm_term=.31f6abc81e1d

The vegetarian allele evolved in populations that have eaten a plant-based diet over hundreds of generations. The adaptation allows these people to efficiently process omega-3 and omega-6 fatty acids and convert them into compounds essential for early brain development and controlling inflammation. In populations that live on plant-based diets, this genetic variation provided an advantage and was positively selected in those groups.
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Re: Rice, arsenic, and evolution

Postby GeoffreyLevens » Thu Feb 23, 2017 10:46 am

And so far as I know, this
The vegetarian allele evolved in populations that have eaten a plant-based diet over hundreds of generations.

has not been studied to find out just how many generations are required; it may well be much less than hundreds!
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Re: Rice, arsenic, and evolution

Postby Helpinghands » Thu Feb 23, 2017 11:09 am

I remember reading somewhere and I'll be darned if I can remember where the number was twenty generations to adapt to a particular food environment.
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Re: Rice, arsenic, and evolution

Postby dynodan62 » Thu Feb 23, 2017 3:16 pm

Helpinghands wrote:I remember reading somewhere and I'll be darned if I can remember where the number was twenty generations to adapt to a particular food environment.


There is genetic adaptation, and then there is environmental adaptation, the latter always occurring within an existing generation. Genes only load the gun. Not all Pima Indians never subjected to strarvation are destined to become obese, and not all eskimos are unable to thrive on vegetarian diets.
I haven't read the Cornell studies, but I would be willing to bet there is no convincing evidence that the human ability to convert ALA is not routinely improved through diet, regardless of genetic predisposition.
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Re: Rice, arsenic, and evolution

Postby GeoffreyLevens » Thu Feb 23, 2017 4:19 pm

dynodan62 wrote:
Helpinghands wrote:I remember reading somewhere and I'll be darned if I can remember where the number was twenty generations to adapt to a particular food environment.


There is genetic adaptation, and then there is environmental adaptation, the latter always occurring within an existing generation. Genes only load the gun.

It is now known that epigenetic changes i.e. those caused by interaction with the environment can be and often are inherited. You parents and even grandparents diets have a major effect on your health, how you process calories, your cancer risks, all sorts of things. And that is just diet; there are likely many areas of life that can be effected by our ancestors environment. From what I have read about the New Guinea highlanders to exposure to kuru and their adaptation and resistance to it, changes can occur in much less than 20 generations.
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