STUDY: Humans evolved to run on less water than relative primates

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(ABC4) – When you begin to think about how far mankind has come mentally, technologically, and physically we see great strides, especially when comparing against our relative primates…But wait! There is another distinguishing feature that sets us apart from our chimpanzee and ape ancestors: water efficiency.

According to a study conducted by Duke University school of nursing, measures precisely how much water humans lose and replace each day compared with our closest living animal relatives and came to the finding that humans have evolved to be run on less water.

As we all know, our bodies are constantly losing water: when we sweat, go to the bathroom, even when we breathe. And in order to keep our blood volume and other body fluids within their normal ranges, water constantly needs to be replenished but apparently not as much as our animal brothers.

In another study, published March 5 in the journal Current Biology, research also illustrates that the human body tends to use 30% to 50% less water per day than our closest animal cousins.

Again bringing us back to the conclusion that among primates, humans evolved to be the low-flow model.

An ancient shift in our body’s ability to conserve water may have enabled our hunter-gatherer ancestors to venture farther from streams and watering holes in search of food, shares lead author Herman Pontzer, associate professor of evolutionary anthropology at Duke University.

“Even just being able to go a little bit longer without water would have been a big advantage as early humans started making a living in dry, savannah landscapes,” Pontzer adds.

According to Pontzer, the research compared the water turnover of 309 people with a range of lifestyles, from farmers and hunter-gatherers to office workers, with that of 72 apes living in zoos and sanctuaries.

He goes on to include that life is all about balance: “water coming in has to equal water coming out.”

Pontzer then goes on to explain, when a person begins to sweat, the body’s thirst signals kick in informing them to take in the water it exerted.

When conducting the study, Pontzer says each researcher calculated water intake via food and drink on the one hand, and water lost via sweat, urine, and the GI tract, on the other hand.

Once all the data is gathered, researchers discovered the average person tends to process about 12 cups, of water each day. According to officials, a chimpanzee or gorilla living in a zoo typically goes through twice that much.

After this was revealed, Pontzer shares that him and team were definitely surprised because ‘among primates, humans have an amazing ability to sweat.’

Courtesy of Current Biology Evolution of water conservation in humans study

“Humans have 10 times as many sweat glands as chimpanzees do,” Pontzer adds.

According to officials, that makes it possible for a person to sweat more than half a gallon during an hour-long workout—equivalent to two Big Gulps from a 7-Eleven. This is even more insane to think about because chimpanzees, bonobos, gorillas, and orangutans tend to live rather lazy lives. “Most apes spend 10 to 12 hours a day resting or feeding, and then they sleep for 10 hours. They really only move a couple of hours a day,” Pontzer shares.

Overall, the study suggests that something changed over the course of human evolution that reduced the amount of water our body uses each day to stay healthy.

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