People adapted to the cold and got more migraines as a result

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Some people have adapted to live in cold polar climates, but at a price. The same gene variant that helps us cope with cold also seems to increase our risk of migraine.

Aida Andrés at University College London, UK, Felix Key at the Max Planck Institute for Evolutionary Anthropology in Leipzig and their colleagues studied the gene for a protein called TRPM8, which is known to activate in cold temperatures.

The gene for the protein comes in two flavours. An older variant, which we share with chimpanzees, is common in people living in Africa. But a newer variant is more common in people living in northern countries, particularly in Europe.

The team screened databases of genetic data taken from people across the world, to see how common each gene variant was in Europe, Africa and South East Asia.

“We found a correlation between frequency [of the gene] and latitude,” says Key. For example, the new variant of the gene is found in around 88 per cent of Finnish people, but only 5 per cent of Nigerians.

Computer simulations suggest that the newer variant evolved in Africa, before people began to migrate to other continents.

“It’s really cool,” says Mark Shriver at Penn State University in University Park. “This is probably the first time [the adaptation of] a sensory gene has been tied to environment.”

A right old headache
The TRPM8 gene has also been linked to migraine. The older variant is thought to protect against the disorder, while the newer variant increases the risk. This may help explain why migraine is more commonly reported in northern countries. “We know the prevalence of migraine is lower in African Americans,” says Key.

It’s not clear why sensations of cold might be linked to migraine, although some people do experience cold-triggered headaches. “That ice cream headache you get is the first thing that comes to mind,” says Shriver.

But migraine is complex, and many factors affect a person’s risk of developing it, says Andrés. In a second study, Padhraig Gormley at Massachusetts General Hospital and his colleagues have shown that many common genetic variants shape a person’s risk of developing migraine (Neuron, DOI: 10.1016/j.neuron.2018.04.014).

It’s also not clear why the often-debilitating pain of migraine would be beneficial. The increased migraine risk associated with the gene variant is probably an unfortunate side effect, says Shriver.

The finding is more evidence that humans have evolved and adapted over the last 100,000 years, even though today we are more alike genetically than most species, says Rasmus Nielsen at University of California, Berkeley.

https://www.newscientist.com/articl...=NSNS&utm_campaign=webpush-Roost-migrainecold
 

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The more I learn about genetics, the more I'm against race mixing. We shouldn't even live together tbh. We evolved for thousands of years in our own climates. I don't belong in Europe.
 

Factz

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The more I learn about genetics, the more I'm against race mixing. We shouldn't even live together tbh. We evolved for thousands of years in our own climates. I don't belong in Europe.

What happens if Somali peninsula becomes all green? Would that benefit us?

Also, race is a real thing and you can tell by the difference in characteristics which means different races were made for a certain environment and that is a scientific fact.
 
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Streets gotta eat
 
The more I learn about genetics, the more I'm against race mixing. We shouldn't even live together tbh. We evolved for thousands of years in our own climates. I don't belong in Europe.

http://www.ign.com/boards/threads/c...ce-humans-have-a-genetic-advantage.192331120/

"Hybrid vigour represents just one point on a spectrum of how related two parents are.

At one end of the spectrum is inbreeding, where the parents are closely related. This tends to produce very unfit offspring, many of which die young. Better is to choose an unrelated partner. When the partner is not only unrelated but comes from a different population, this is like being ‘super-unrelated’ and can lead to hybrid vigour. However, there must be an end-point where the parents are too different. Most obviously this end-points comes when the parents are so unrelated they are actually different species. Thus, when a donkey and a horse mate the offspring are called mules. Mules are interesting because the show some elements of hybrid vigour, being strong and hard-working, but they are also infertile.

What is the basis of ‘Hybrid Vigour’?

There are two main components of hybrid vigour, referred to as ‘outbreeding’ and ‘heterozygote advantage’. Humans have 23 pairs of chromosomes containing about 30,000 genes. Only the sex chromosomes break the ‘pairs’ rule, women having two ‘X’ chromosomes and men one ‘X’ and one ‘Y.

If you carry two copies of a gene that differ slightly in how they work, it is a bit like having an extra channel on your TV set: you don’t have to watch it but there may be times when the extra channel comes in handy. It gives you extra flexibility. An individual who has two identical copies of a gene (good or bad) is called a homozygote, while someone who has two copies that differ is called a ‘heterozygote’.

The benefit of outbreeding

Broken genes are usually rare, so to inherit two broken copies of the same gene is unlucky and can result in serious health problems. However, the chances increase considerably if your parents are related. With more genes that are identical by descent, a child will have more genes where both copies are broken.

If inbreeding is bad, outbreeding, marrying an extremely unrelated partner, should be good for the same reason. With a less related partner, the number of genes in your children that are identical by descent is reduced, and with it the chance that a gene has two broken copies. It is not that your children will inherit fewer broken copies in total, just that every broken copy has a much better chance of finding itself partnered with a good copy.

The benefits of heterozygous advantage

Outbreeding can be thought of as avoiding the bad effects of having two broken copies of the same gene. Heterozygous advantage deals with the extra flexibility one may get from having two good, but slightly different copies of the same gene.

Is there hybrid vigour in humans?

So, what happens when people from different human populations marry - is this likely to bring the benefits discussed above? Yes, it probably will, says Amos, both by reducing the number of gene-pairs that are broken and by increasing the number that are ‘both-good-but-different’. Combined, the result should be, on average, children who are genetically healthy, for example, who are less likely to catch ‘flu or who live a little bit longer. However, the size of this effect is extremely difficult to measure because so much of a human’s fate is due to the environment: having good genes won’t stop you getting run over by a drunken motorist!"
 
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