Do humans that have evolved in dry places, like Africa and the Middle East, have more water-efficient bodies?

All humans evolved in Africa.

@ragingloli has a point. I do believe that there is an adaptation for more efficient sweating and use of water. I remember learning about it some time in med school. That said that was 35 years ago and I could just be blowing smoke out of my ass.

^^ That might be something worth seeing!

@Dutchess_III Humans evolved all over the planet and populations have different adaptations based on the specific needs of their locality. Humans do share a common ancestor in Africa though.

The first true humans evolved in Africa. They moved out from there. Most DNA mutations on the journey proved to be useless, but some turned out to be useful. Lighter skin in Europe proved to be useful. It absorbed vitamin D from the sun better than dark skin.
Back in Africa that wasn’t necessary.

Here is a fantastic documentary of the odyssey. I could watch it every week.

The adaption for more sweating was mentioned during the women’s marathon run in Tokyo. I’m not sure that would be evolution in a particular region of the world, or evolution in general for human beings. It is an adaption most humans are capable of.

Human beings have the ability to adapt to environment, sweating more efficiently when spending a lot of time in hot climates or doing regular intense exercise is a really phenomenon. Also, building specific types of fat in colder climates and changes in blood and arteries.

People overuse this idea of acclimation as an excuse for how they feel in the heat or cold. I hear it all the time living in Florida. They will say their blood has thinned living here and now 60 degrees feels cold. The truth is, just being here a day people will complain 60 degrees is cold, and that is not an adaption, that is thinking you only need shorts and a t-shirt in Florida 365 days a year and refusing to put on warmer clothing. Plus, we have higher humidity which makes cool weather feel colder.

Cold weather can thicken the blood though as an attempt to keep you warm. Thickens and arteries and veins move in closer to the interior of your body away from the skin. Blood concentrates towards vital organs and your extremities are at risk. Within time your body adjusts so these protections are not so severe. Sudden cold weather is dangerous. I know the last thing I need is thicker blood and increased risk of clotting.

In the US we don’t acclimate much, because we have central air conditioning and heat in most places where the weather is more extreme.

If evolution has been affecting our ability to handle various climates, the advent of air conditioning and heaters certainly has put a dent in the possible continuing process into the future.

I’m no expert, but this is what I’ve learned over time.

Good question. But the answer isn’t exactly simple – And lately how we discuss it includes some awkward cultural baggage.

There are in fact notable differences in skin structure and gland chemistry, linked to environmental adaptations. But a lot of the science examining this diversity has become confused by different reactions to “race theory” over the last 50 years.

Ethnic Differences in Response to Thermal Environments :
https://www.sciencedirect.com/science/article/abs/pii/030645659390047W

Environmental Selection During the Last Ice Age :
https://www.pnas.org/content/115/19/E4426

Race and Body Odor:
https://notpoliticallycorrect.me/2016/10/04/race-and-body-odor/

Even though genome reserch confirms there’s only a 1% variation in all human genetic composition; careful analysis does reveal significant differences in “genetic expression” – How certain physical traits emerge as adaptations. In particular the EDAR – V370A variant can account for exactly the sort of thing loli is asking about. BUT – because these differences in gene expression emerge as race/ethnic features, talking or even thinking clearly about what it may mean gets tangled up in politics and personal sensitivty.

@JLoon wins this question.

@Caravanfan, and Everyone – Thanks!

But I think I only get a bronze medal (maybe if I sleep with the judges) – because the best answer to a question like this just takes more effort than what I put in. Substance still counts more than style.

For instance, I said there’s just a 1% variation in total human genetic composition. Wrong. It’s actually only 0.1% : https://www.genome.gov/dna-day/15-ways/human-genomic-variation

I think that matters because it means that given this small degree of actual difference, genetic expression on a cellular level can have huge outcomes. Not just in characteristics like loli is talking about, but in all kinds of physical development. And to me this means that instead of dividing humanity up into a phony heirarchy based some notion of “superiority”, it should really open our eyes to the value of differences. All the political blather aside, diversity means resilience. It’s literally built into our bodies. And it may be our best hope for adapting & surviving as a species.

@Dutchess_III Here is a fantastic documentary of the odyssey.

I tried your link, but it just led me to a picture. Is that what you meant?

No. It was a PBS documentary hang on.

Try this

Lol! Some picture @smudges!

@Dutchess_III Ok, that did it, thanks! I know…weird pic! LOL

Well, it’s me in HS. It was meant to post in the “Why the hell do kids buy ripped jeans?” Thread.
I probably posted my Nova documentaries on THAT thread!
Dutchess is losing her mind!

@Dutchess_III It was right on that thread.

Oh good! Thank you.