180k-Year-Old Mutation Allowed Humans To Become Vegetarians, Move Out of Africa 342
An anonymous reader writes "Early humans were able to move from Africa after a single genetic mutation allowed them to become vegetarians, scientists claim. The switch, which allowed humans to process vegetables, meant that humans were able to move away from water sources and spread across the continent. A team of geneticists compared DNA sequences from a variety of people around the world to see how different populations relate to one another and when they have gone their separate ways. The scientists found that a key genetic variant gave humans the ability to convert fats from plants into essential nutrients for the brain."
Re:Vegetarian? (Score:5, Informative)
We were already omnivores, this allowed us to not be required to eat certain foods (fish and shellfish), so we could survive away from the sources for those.
Re:Vegetarian? (Score:5, Informative)
No, humans were omnivores before, same as other primates. Omnivore means having a diet of both meat and plants, both in large quantities. It doesn't mean that you can survive on either just meat or just plants alone. Indeed, most omnivores require a mix of meat and plants for the diet to be healthy.
So far as I can see, this mutation is not truly vegetarian, either - it lets us reduce meat consumption in favor of plants, but not replace it entirely.
can i haz teh dictionary? (Score:5, Informative)
The scientists found that a key genetic variant gave humans the ability to convert fats from plants into essential nutrients for the brain."
To this?
180k-Year-Old Mutation Allowed Humans To Become Vegetarians, Move Out of Africa
People who don't know their scientific terms mis-quote scientific articles. News at 10.
Re:is it a mutation? (Score:5, Informative)
We'll go in order...
mutations are so rarely beneficial
The vast majority of the mutations that are widespread through the population are either benign or beneficial. The ones that aren't don't stick around in the gene pool long enough to become widespread. It's the other half of the selection pressure you mentioned: The selection pressure culls bad mutations out quickly, so the good (or at least ineffective ones) are all that's left. This is definitely a case of history being written by the victors: The bad mutations don't usually stick around long enough to be noticed (in long-term history).
So how do they know it was a mutation?
Because some folks have it, and other folks don't. From the geographic distribution of where the haves and have-nots are, combined with the prevailing theories about human movements, the researchers can estimate what genetic group first got the change.
one mutated birth isn't going to suddenly diffuse across an entire species.
It doesn't happen suddenly. That one mutation spreads through one family, who suddenly has the ability to survive without eating fish (substituting vegetables, instead). Over the next thousand years or so, that family (and the associated mutation) spread across the local region, and the knowledge of "it's okay to eat vegetables" spread with it. Since that group could wander further (carrying longer-lasting vegetables rather than fish), they spread farther than other groups, until they eventually became dominant.
How one random gene in one birth suddenly afflicts an entire population?
Just to be clear, it doesn't. The one random change will be in one family line, and only really become widespread if it allows the family to outgrow the rest of the population, or if the the rest of the population dies off.
Headline wrong (Score:5, Informative)
The Slashdot headline is wrong and the initial website it links to has a wrong headline.
If you read the scientific paper, it says the mutation happened about 85,000 years ago, not 180,000 years ago. This makes it logically consistent with other biological discoveries, archaeological finds etc.
Re:is it a mutation? (Score:5, Informative)
Basically, I don't understand this article.
The problem isn't the article. It's your limited understanding of evolution and genetics. :-)
According to modern evolutionary theory, mutations create ALL change. Most mutations don't do something favourable, or really actually probably don't do anything at all, but some of them are favourable and those individuals go onto spread that gene more effectively than their peers until many many generations later, this gene has spread throughout the species (or the region, or the tribe, etc).
If a tribe of ancient humans gradually gained the ability to survive without meat, and a major event such as volcanic eruption or something killed off the local food staple, the tribe that could survive for years without meat might be the only survivors in the entire area. If the species is isolate to that area, they could plausibly be the only survivors of the species.
In this way it is actually possible for the entire species to gain a trait in just a few generations. Or, a mutation can gradually make its way into cultures in a more limited sense.
For example, genetic analysis suggests that ALL blue eyed individuals are descendants from a single individual with a unique mutation about 6-10,000 years ago. People with brown eyes have a huge variety of genes that affect pigmentation, whereas all individuals with blue eyes have a very specific sequence that controls it, which, along with mitochondrial DNA surveys, leads researchers to conclude the bit about a single individual.
Pretty cool, eh?
Re:Oh wait, I get it now... (Score:5, Informative)
TFS was worse than the normal FS. First off, the "vegetarian" bit. Now that I've RTFA, we were omnivores, but we needed fish or our brains wouldn't develop propery, so we were stuck living near the ocean. Once we could live without fish we could live anywhere.
It had nothing to do with vegetarians, the sumitter is probably one of those PETA vegan nuts.
Re:is it a mutation? (Score:5, Informative)
"one mutated birth isn't going to suddenly diffuse across an entire species."
you're right:
1. what happens is those without the mutation die or have less children or no children, or are confined to one small environmental niche
2. while those with the mutation live longer or have more children or move over a wider range taking advantage of a wider range of food
and you're wrong:
1. it could start with one single mutation in one individual
2. it does diffuse across an entire species: that's what sex is for
3. it does happen suddenly, on the time scale of geological time
Re:Vegetarians? (Score:2, Informative)
Vegetarians. You keep using that word, but I don't think it means what you think it means.
Re:is it a mutation? (Score:3, Informative)
According to modern evolutionary theory, mutations create ALL change.
Caveat: this is only true if you define "mutation" very broadly. Usually, when biologists say "mutation," it means a change in the DNA sequence, but we're learning more and more about heritable non-sequence changes (this usually goes under the name "epigenetics") which can also affect phenotype, and thus have an evolutionary impact. It's still true as far as we know that most heritable changes are sequence changes, but by no means all.
At some point we're going to have to adapt our vocabulary to deal with this, perhaps by returning to the old meaning of "gene" as "a unit of inheritance" and expanding the meanings of "mutation," "expression," and related terms accordingly. It hasn't happened yet, because the accepted meanings have served us well for 50+ years, and technical jargon is often, quite reasonably, very resistant to change.
Re:More interesting than that... (Score:2, Informative)
Exactly, we owe our big brains to the energy starch gives us. Very few primates can digest starch while diferent human groups developed civilization the day they domesticaded a starchy plant (rice, corn, potatoes, wheat, etc.)
Re:can i haz teh dictionary? (Score:4, Informative)
The point is that the mutation (putatively) allowed humans to survive on a vegetarian diet, when they couldn't do so before.
Uh, you need to read how to learn, as well as how to apply logic. What the article says ("ability to convert fats from plants into essential nutrients for the brain") does not mean (or imply) "avoid meats by choice". It doesn't mean/imply ("ability to survive on plants alone"). It simply means "ability to exploit a greater variety of food products for brain sustainment with greater efficiency".
That is all. Any other interpretation is not an interpretation of logic, but of choice (aka "wishful thinking").
This would be very valuable for a nomadic "hunter-gatherer" lifestyle in times and places where there was plenty to gather but not so much to hunt (or fish, as the case may be).
Inconsequential. That does not imply vegetarianism (be it voluntary as in humans or mandatory as in herbivores.) In the name of Jebuz, buy a dictionary or use google and learn the meaning of the word "vegetarian".
Re:Vegetarian? (Score:5, Informative)
Humans require B12 which can only be obtained from animals.
That's not entirely true. Animals don't produce B12, it is produced by single celled organisms that are omnipresent in nature. Animals consume it while eating vegetables because they don't wash them. We do, and that's why we can't get enough of it through an ordinary vegan diet. If we lived in nature, we would. So the supplement a vegan needs to get is something that is previously removed from the food source.
Re:Vegetarian? (Score:4, Informative)
Vegetarian != vegan.
Re:Vegetarian? (Score:3, Informative)
B12 is produced by microorganisms, and apparently that's where most animals get their B12 from -- e.g., eating soil.
Cyanocobalamin is the usual B12 supplemental form and can be obtained in tablet form over the counter or from supplemented foods.
Nutritional yeast is usually supplemented with B12, though the amount varies. Looking at a few labels: KAL Yeast Flakes lists "150% Daily Value" in 3 rounded tablespoons; Red Star Yeast VSF (flakes) lists 8 micrograms or "133% Daily Value" in 2 heaping tablespoons; and impressively, Twinlab SuperRich Yeast Plus lists 25 micrograms or "416%" in 2 tablespoons.
Many people find that nutritional yeasts taste good. I sprinkle yeast flakes on popcorn and mix yeast into soup or over pasta both for the nutritional boost and because it's a source of umami flavor:
http://www.thekitchn.com/umami-for-vegans-136507 [thekitchn.com]
Brits and Aussies have Marmite and its clones:
http://www.marmite.com/love/nutrition/vitamin-b12.html [marmite.com]
Re:Vegetarian? (Score:5, Informative)
You are comparing people that are very conscious and strict about their diet that happen to have one (debated unhealthy) habit to the average of a very unhealthy nation of people.
If you were to compare honestly, you would take a large sample of vegans of all ages, gender, income group and compare those to people equally concious about what they eat but meat eaters. Factor in the same distribution of age, gender, income group, since vegans tend to be either religious (Buddhist monks for instance) or not poor and living in western countries.
I think you will find that the vegans will not be healthier in general. They may be healthier on specific diseases related to eating meat and unhealthier on factors related to missing essential nutrients that are common in animal produced food but are hard to get in your diet if you are vegan. From what I understand from dietary scientists I happen to know, is that the diseases typically linked to eating meat will probably be a lot more rare than (developmental) diseases from not eating meat in the entire group of tested people. This probably is never truly researched in a way that I propose here, so maybe someone not related to vegan or meat food industries will be willing to sponsor adequate research? Maybe they will find new diseases, or causes for diseases or symptoms not yet discovered.
Re:Vegetarian? (Score:2, Informative)
2 things in a vegan diet contain b12, mushrooms and bananas.
More important than actually supplying B12 is the secretion of 'intrinsic factor' which is what allows the body to absorb B12 from the diet. Also intestinal floraproduce B12. Learn something beyond the traditional anti-vegetarian/vegan propoganda and you might actually learn something worth knowing. Many 'facts' about vegetarianism come from outdated literature like the idiotic idea that one needs to combine 'complementary proteins' from Frances Moore Lappe and her book 'Diet for a small planet' .
99% of what people believe about vegetarianism is complete hogwash. Being from NZ, being a vegetarian is no mean feat, but in my case it was necessary to prevent chronic gut ache on the standard NZ diet of meat and spuds. I have refused for some time to shovel meat and dairy down my gullet like it's going out of production because frankly, it made me ill. I know a few vociferous meatatarians who don't realise the harm chronic overindulgence in meat can lead to.
I have been a vege for nearly 30 years, how about you?