Home / Science / A new study suggests humans have evolved to use less water than our closest primate relatives.

A new study suggests humans have evolved to use less water than our closest primate relatives.


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When you think about what separates humans from chimpanzees and other apes, you might think of our huge brains or how we walk on two legs instead of four. But we have another distinct feature, water efficiency.

This is a new take-home study that is the first to accurately measure how much water is lost and replaced by humans on a daily basis compared to our closest living animal relative.

Our bodies constantly lose water: when we sweat, go to the bathroom, even when we breathe. It is necessary to add water to keep the blood and other body fluids within the normal range.

Still, the research was published in the journal on March 5. Current biology It has been shown that the human body uses 30% to 50% less water than our closest animal cousins ​​per day.In other words, among mammals, human has evolved to be a low-flow model.

Lead author Herman Pontzer, associate professor of evolutionary anthropology at Duke University, said ancient changes in the body̵

7;s ability to conserve water could allow our predatory ancestors to venture further from streams and water holes to find. Diet Herman Pontzer, lead author, associate professor of evolutionary anthropology at Duke University.

“Even being able to live a little longer without water was a huge plus when early humans began to make a living in the barren savannah landscape,” said Ponser.

The study compared the water circulation of 309 people in diverse lifestyles, from farmers and hunters to office workers, with 72 monkeys living in zoos and sanctuaries.

To maintain fluid balance at a healthy level, a human or other animal’s body is like a bathtub: “The water that comes in has to be equal to water,” says Ponser.

For example, dehydration from sweating and the body’s thirst signals kick in, telling us to drink. Drink more water than your body needs and your kidneys will remove excess fluid.

For each person in the study, the researchers calculated the amount of water through food and drinks in turn, and the water lost through sweat, urine and vice versa.

When they increased all inputs and productivity, they found that the average person consumed 3 liters or 12 cups of water a day; more than twice as many chimpanzees or gorillas living in zoos had to pass.

Pontzer said the researchers were surprised by the results, because among the mammals, human mammals were able to sweat remarkably. Per square inch of skin “Humans have 10 times more sweat glands than chimpanzees,” said Sponsor. That leaves more than half a gallon of sweat during a 1-hour workout, equivalent to 2 bottles of Big Gulps from a 7-Eleven.

In addition to the fact that great apes – chimpanzees, bonobos, gorillas and orangutans, live lazily, “most apes spend 10 to 12 hours a day resting or feeding, then they sleep. 10 hours, they only move for a few hours a day, ”said the sponsor.

But the researchers controlled differences in climate, body size, and factors such as activity levels and calories burned per day. So they concluded that saving water for humans is real, not just the function of the individual who lives or is physically active.

Research suggests that something has changed with human evolution that reduce the amount of water our bodies use each day to stay healthy.

Then, for now, we should only be able to live for a few days without drinking, Pontzer said. “You probably won’t break that ecosystem leash. But at least you get a longer line if you can go longer without water.

The next step, Pontzer said, is to identify how this physiological change occurred.

One hypothesis suggested by the data is that the body’s appetite response has been re-engineered so that overall, we are thirsty for less calories compared to our monkey relatives. Even if it’s a baby But before our first solid meal, the water / calorie ratio of breast milk was 25% less than that of other monkeys.

Another possibility is ahead of us: Fossil evidence shows that some 1.6 million years ago, with the inception of Homo erectus, humans began to develop a higher nose. Our cousin’s gorillas and chimpanzees have very flattering noses.

Our nasal passages save water by cooling and condensing steam from the exhaled air, converting back to a liquid on the inside of the nose that can be reabsorbed.

Having a more protruding nose might help early humans retain more moisture as they inhale.

“There are still puzzles that need to be solved. But it’s clear that humans save water, ”said the sponsor. “Figuring out how we do it is where we go next, and it’s going to be a lot of fun.”

Elephants were found to have the greatest amount of water loss ever recorded in land animals.

More information:
“The Evolution of Water Conservation in Humans,” said Herman Pont, Sir Mary H. Brown, Brian M. Wood, David A. Schaffer. Reichelordz, ZP Mabulla, Jacob A.Harris, Holly Dunsworth, Brian Hare, Kara Walker, Amy Luke, Lara R. Dugas, Dale Schoeller, Jacob Plange-Rhule, Pascal Bovet, Terrence E Forrester, Melissa Emery Thompson, Robert. W. Jessica M. Rothman, Erin Vogel, Fransiska Sulistyo, Shauhin Alavi, Didik Prasetyo, Samuel S. Current biologyMarch 5, 2021 DOI: 10.1016 / j.cub.2021.02.045

Provided by Duke University School of Nursing

Reference: New studies suggest that humans evolved to use less water than our closest primate relatives (2021, March 5) .Retrieved March 5, 2021 from https://phys.org/news/2021-03. -humans-evolved-closest-primate-relatives .html

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