Link #6: Redheads Comprise About 2% of the Global Population
The effect of evolution, as we described in our previous post, is that certain species survive better than others in their environment. From this, you can draw the conclusion that the effect of evolution is improvement of the species, with respect to the immediate environment. Despite this obvious correlation, many people think that there is no reason behind the existence of redheads. Does it come to you as a surprise that they’re wrong?
2% of the Global Population Has Red Hair

Estimates suggest that about 2 percent of the global population has red hair. Depending upon the number of people living on the planet, this means that there about 140 million people in the world who are redheads. If you take the same ratio of redheads to other Caucasians and apply it to countries, then you’ll find that it’s the America that has the most redheads in the world.
However, the same ratio cannot be applied to different countries. With technology, people have stopped depending on their natural capabilities as much as they did earlier. In those times, people couldn’t travel long distances in hours and couldn’t use devices to counter nature. For instance, ideally, northern European countries such as the United Kingdom should have far more redheads than the rest of the world. This isn’t true, however. As per census estimates, 10 percent of people in the United Kingdom are redheads, which converts to around half a million.
Redheads Evolved Amongst Humans Living in Low Sunlight Areas

The big question that you must have is how and why did redheads evolve in the first place? This is a purely scientific query that can only be answered by going to the time when mankind was spreading out from warmer to cooler climates. Largely, this migration occurred from Africa. This means that dark-skinned and dark-haired people started moving to areas which were not only cooler but also had less sunlight.
This lack of sunlight is what prompted the change in complexion and, by extension, hair color. The human body needs vitamin D to survive. Vitamin D is created with the help of sunlight. However, darker skinned people had more melanin, which prevented sunlight from penetrating the skin.
Effectively, to compensate for the lack of vitamin D due to the lack of sunlight, mankind evolved pale skin, skin with less melanin. Red hair is a by-product of low amounts of pigments in the body. Redheads, as a result, are much more efficient at producing vitamin D than their darker haired counterparts.
Other Ways That Redheads Are Different
Redheads are different in other ways as well, but the reason for those differences is the same as above, that they evolved for a particular environment. For instance, you’ll find that redheads are more sensitive to cold but less sensitive to pain administered through the skin. Each of these characteristics makes redheads better able to survive and function in areas where sunlight and temperatures are low.
Can you Guess the Next Link in the Chain?
What will be the next link in our Chain of Facts? Think you might know? Scroll down to add a comment below with your best guess.
You can view the full list of links in the chain here.
Sources:
http://www.bbc.com/news/magazine-24331615
http://sciencenordic.com/redheads-feel-different-kind-pain