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How curly hair played key role in survival of the human race

This is the first analysis of hair type in an evolutionary context.

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(Photo by Lee Chinyama via Unsplash)

By Mark Waghorn via SWNS

Black people's curly hair played a key role in the survival of the human race, according to new research.

Tightly coiled locks protected our ancestors against the burning sun, scientists have revealed.

Curls stopped their heads from overheating - without causing excessive insulation. It explains why the trait evolved in Africa. Straight strands would have wiped them out.

The reason for the unique characteristic has been a mystery. Theories have included genetics, hormones or body chemistry.

As early humans migrated to cooler areas manes began to unwind over time, explained lead author Dr. Tina Lasisi.

The selective pressure for tightly coiled hair would have been lost. It allowed variations to emerge from generation to generation by random chance.

The study, reported in New Scientist, suggests that curly hair was actually our species' savior.

It may change prejudiced views, say the US team.

Lasisi, of Penn State University, suspected a particular type of hair would have shaded our bipedal ancestors.

Her team put three different wigs - one straight and the other two with moderate or tight curls - on a manikin.

The human model, normally used to measure the thermal effects of clothes, was equipped with heaters and sensors.

In tests in a wind tunnel with simulated sunshine at 86°F, the head with a straight wig gained less than half as much heat as a bald control.

This was reduced to a quarter by the moderately curled wig - and less than a tenth by the tightly curled one.

The latter was similar to the hair sported by people of African descent.

It is believed curls dramatically decrease the amount of heat that reaches the skin by widening gaps to the surface of the hair.

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Long straight hair doesn't achieve this because it flops over and lies flat, explained Lasisi.

Curlier hair also maximizes the shielding effect from the sun while minimizing an unwanted insulating effect.

Lassi said: "It has this incredible way of bypassing this trade-off."

The results also showed tightly coiled hair reduced the amount of sweat required cool the head more than moderately curled or straight hair.

Professor Joseph Graves, an evolutionary geneticist who was not involved in the study, said: "Any mechanism that could help cool the body, and at the same time save precious water, would definitely have been acted on strongly by natural selection."

It offers hope of eroding racist ideas. The first humans would have had black skin and tightly curled hair.

Graves, of North Carolina Agricultural and Technical State University, is the co-author of "Racism, Not Race." He said it was only relatively recently other skin colors and hair types appeared.

Biologists have begun to study the evolution of skin color. But this is the first analysis of hair type in an evolutionary context.

Dr. Gill Westgate, a skin and hair expert at Bradford University, said: "This is indeed a first-of-its-kind study.

"It's fascinating that curly hair protected against incident solar thermal effects - which would have been important in the development of bipedal hominins."

Hair type has previously been studied by researchers in fields such as cosmetics and forensics but not from an evolutionary perspective.

Lasisi said: "When it comes to anthropology, it has this history that's tightly woven with colonialism and racism.

"What kind of Victorian gentleman would have thought a trait he did not possess could be critical to human evolution?

"Biologists study skin color evolution but this is the first study to look at the evolution of hair type."

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