back to article Humanity evolved to cope with 30°C+ heat, says prof

Many of humanity's distinctive features - walking upright, hairlessness, the ability to sweat copiously - arose due to the fact that the place where we evolved has been scorchingly hot for millions of years, according to noted boffins. The cradle of humanity, according to most research, was the Turkana Basin in Kenya's Great …


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  1. ravenviz Silver badge
    Thumb Up

    Well then

    I become more of an atheist every day

    1. Steven Knox

      Non sequitur

      That is all.

    2. IMVHO


      @raveniz: I become more of an atheist every day

      God told me, just last night, that hairless, moist atheists are his sexiest creation. If you're in the rift valley sometime, let's have a starbucks before mass.

  2. DJV Silver badge


    And if we'd originated in Blighty instead of Kenya we'd probably all be rather hairy and have gills.

  3. Volker Hett
    Thumb Up

    as I told anybody for decades!

    That winter nonsense is made up by the wintersports industry!

  4. Doug Glass


    Where I live the temps hit 30c in early April, spend weeks on end at 35c+, and by late August there are peaks that pass 37.77777 (100F) more often than I can count; 30c is a cool wave. And we love it for boating, hiking, swimming and such. This is news only to people who haven't experiemced the finer climates.

    Want cooler? We travel.

    1. Ugotta B. Kiddingme
      Thumb Up

      quite right, but one question

      in the southeastern U.S., temps between 30c and 40c are not only common, but are also accompanied by 90%+ relative humidity levels. Yes, it's rather warm. The humidity makes it extremely uncomfortable because the evaporative cooling effect of sweating just doesn't work. The only thing one gets is smelly damp clothing.

      Now in the much drier climes of the southWESTERN U.S., temps reach well over 40c in the summer, but the low relative humidity allows evaporative cooling to work as intended. So long as one remains appropriately hydrated, it's not that uncomfortable at all.

  5. D@v3

    If we are "designed to live in a scorchingly hot climate"

    Then why does everyone in the UK complain it's too hot when the mercury hits 25c?

    <-- Coz their hot, innit.

    1. Nigel 11

      Humidity is what's horrid

      I've been in Arizona in summer (well above 40C at times) and it's quite OK once you get used to it, provided (big proviso) you have enough water at all times. Your sweat evaporates immediately and keeps you cool. You drink gallons and need to eat more salty snacks than usual to avoid cramps. Run out of water and you are in serious trouble.

      People can work in steel-mills where I'm told it's even hotter than this.

      I've also been in Philadelphia in a heatwave. Nowhere near Arizona hot, but very humid. Your clothes get soaked with sweat, stick to your skin, start dripping. There's so much water already in the air, that sweating doesn't solve the heat problem. Really, really horrid weather if you want to do anything outdoors. Go into an air-conditioned interior and you shiver until the sweat in your clothing has evaporated into the over-cool dehumidified air. Why do USAians set the indoor thermostat at 68F in Summer, rather than 75F?

      So yes, I can believe that we are evolved for hot low-humidity surroundings. Only one question - where did prehistoric man in the Turkana find enough fresh water to survive and thrive?

  6. John 90

    Break out the patio heaters!

    Next up from evolution - upright, hairless, sweaty giraffes. And likewise snakes, and anything else that lives in Africa.

  7. Anonymous Coward

    Not if you're ginger :^(

    We might have started off somewhere nice and hot, but northern dwellers tend to simultaneously crisp and melt when the temp approaches 30 degrees C.

    This weekend --- hopefully --- we'll see how well UK man and woman handle a moderate heat.

  8. Sweep


    Why aren't other mammals in hot(ter?) environments not (relatively) bald too? Only other bald mammals I can think of are either aquatic, burrowing or really big...

    And, if we evolved certain physical characteristics to cope with an extremely hot and dry environment, getting rid of lots of water in the form of sweat doesn't seem like a particularly good survival makes us ming too.

    1. The Original Ash

      Humans ming?

      All animals bathe to one degree or another. Try it sometime!

    2. lawndart

      Cursorial hunters

      Man has one outstanding ability amongst the animal kingdom; we can endurance run like pretty much no other. We can be outdistanced by almost all animals in a sprint; gazelles, wildebeest and other plains dwellers can outrun us for a bit but then their muscles get tired and we catch up, and keep on coming in for the kill on a prey that is too exhausted to get away or even fight much.

      A long distance runner has to shed heat efficiently to maintain the pace, so a reduction in hair/fur would be beneficial, as would the sweating for cooling. Once you have flushed out the prey you don't need to be too subtle about running it down, being a bit whiffy makes little difference once the prey knows you are there. Even water should not be too much of a problem. Humans are social animals and hunt in groups. Get thirsty and break off for a drink while the rest of the hunters carry on pushing the prey past it's limit, rejoin when you can and give someone else the chance for go for a drink.

        Thumb Up

        Other endurance predators.

        I like your (plausible) theory, but it doesn't explain why the hunting dogs of Africa and the peccaries of South America (for example) are hairy (although admittedly short-haired), and neither species sweat (although both do ming a bit...)

        1. lawndart

          re: Other endurance predators.

          Good point about the Cape Hunting Dogs. Canines evolved a completely different cooling strategy - they cool themselves by panting rather than sweating, which can be sufficient for a CHD size long distance hunter, but problematic if the animal is larger due to the limited area of mouth and tongue for evaporation. This would less of an issue for a sprinting dog, which would tire quickly anyway. I think this cooling strategy may be the primary size inhibitor for canines. Given this size limitation some form of camouflage and defense from wiry undergrowth and cornered prey would enhance the benefits of a fur coat to protect the skin.

          I can't comment on peccaries - I know little about them.

      2. Sweep


        I was going to mention dogs/ wolves but another poster already has, and your answer sounds reasonable.

        Human ancestors were bipedal long before they ate meat at all, never mind hunted, so I don't see being able to run down prey as a valid reason for the evolution of bipedalism, although it could certainly be a reason for humans being mostly hairless (one of my ex girlfriends being an alarming exception).

        TBH I don't think there's any one reason why we are the way we are (although the aquatic ape theory tries to explain a whole bunch of human features) . I don't know if bipedal locomotion is any more/less efficient for walking than walking on all fours the way a dog/cat/horse etc does, and in any case that's a false comparison, the point is probably that it's more efficient than knuckle-walking on the ground the way other apes do, and has other benefits which would/ could have been an advantage and led to the increased fitness of bipedal proto-humans (leaves hands free, etc etc etc).

    3. Anonymous Coward
      Anonymous Coward

      Indeed . .

      Does anyone know the current status of the 'Aquatic Ape Hypothesis'? Has it been comprehensively discredited or is it still the awkward relative that everyone would like to get rid of but can't really find the words?

  9. Duncan Hothersall


    Adam and Steve were created by the FSM and His Noodley Appendage.

  10. Anonymous John
    Thumb Up


    Roll on global warming, then!

  11. Anonymous Coward
    Anonymous Coward

    Now if the boffins would only explain...

    ... why sweat stinks so much. It can't be evolution stuck us with that just to force us to shower regularly. Or did the shower and bath industry lobby get hold of a time machine or something?

    1. Sarah Bee (Written by Reg staff)

      Re: Now if the boffins would only explain...

      Fresh sweat doesn't stink. Old sweat does because of bacteria. And people didn't used to be fussed about a bit of smelliness, anyway, it's only relatively recently that someone invented soap and had to stoke up a lot of paranoia about BO to make people buy it.

      Y'know, more or less.

      1. The Original Ash
        IT Angle

        Apologies, Ms Bee

        People most certainly did care about smelliness. Why do you think the Bourgeoisie carried pomanders and other scented adornments during the Middle Ages? A handkerchief soaked in scented oils, maybe?

        Besides, soap is the lazy man's cleaning product. In ancient Greece it was preferred to apply hot wax or oil to the body and strip it off, like many a lady is prone to doing nowadays (only for different reasons). It was much more effective at removing dead skin and other particulates than soap is, leading some to believe the ancient Greeks were more cleanly than we are today.

      2. Eddy Ito

        Re: Fresh sweat, BO & paranoia

        I'd also wager that old sweat didn't hang around long in the arid heat of the Turkana Basin. The whole BO thing probably got started about the same time we got clothes to hold on to the sweat and the church figured we shouldn't be naked when it's hot. Before I figured the church out, I always wondered how Adam and Eve were bothered by being naked when so many indigenous people in tropical climes don't seem to care so much.

        1. Sooty

          RE: apologies

          "People most certainly did care about smelliness. Why do you think the Bourgeoisie carried pomanders and other scented adornments during the Middle Ages? A handkerchief soaked in scented oils, maybe?"

          People did not care about bad smells, from the smelliness angle anyway, however some clever chap managed to associate people dying of plague with them being in particularly smelly areas. Thus they started thinking bad smells caused the plague, that was the reason for the oils and handkerchiefs.

          Ironically, cleaning up what caused the bad smells, also got rid of the rats, causing less people to get sick!

        2. Anonymous Coward
          Thumb Down


          But I think Pomanders and their ilk were aimed at warding off noxious vapurs which were believed to be carriers of disease rather than to disguise poor personal hygiene. I also 'think' you may be mixing eras in that the Bourgeoisie came some time after the Middle Ages.

    2. Magius

      Sweat does not stink...

      But when bacteria start going through it what they leave behind does stink, you know what I am talking about.


      To ming or not to ming...

      The stink is the by-product of the bacterial degredation of the sweat. Capitalism is to blame for people worrying about minging! I believe that the personal hygiene industry was largely created by the advertising campaigns of Lifeboy soap etc.

  12. Anonymous Coward
    Anonymous Coward

    So humans ARE better than other animals!...

    ...because we were the only species in this scorching heat with the good sense to evolve this way.

    The chimps and gazelles that came from the same place were stupid enough to keep their fur!?

    That heat theory suggests that no other mammal evolved under those same hot conditions, because otherwise they would very likely have evolved in the same way. Dismissed.

    1. Ross 7

      Natural selection

      Ummm, natural selection doesn't work that way. Things don't evolve to suit their environs. They mutate entirely randomly - if the mutation harms them they die off and are less likely to have offspring that survive to carry on the mutation; if the mutation helps them they are more likely to have offpsring that survive to carry on the mutation and so the population is more likely to end up with the new/improved feature.

      If gazelles, chimps etc never had the random mutations that reduces hair/increases sweat etc then they won't have those features. If they did have those mutations but the one creature that had it got eaten/disease/wasn't strong enough to get mates etc then it won;t show in the population.

      In other words, we got lucky.

    2. Anonymous Coward
      Anonymous Coward

      I suggest

      you read up on how evolution works, then leave the clever stuff to people like the ones who wrote the paper. Who, almost by definition, know more about this than you or I do.

  13. Anonymous Coward


    How come I'm not bald?

    It often gets to 45oC+ around here.

    1. Anonymous Coward

      This article is crap! CRAAAAAAAP!!

      I completely agree. 30-35 C is only 85-95 F. Where I live in the American Midwest, 30-35 C is what we call summer! In fact, temperatures generally get up to 40 C (105 F) every August. I've never been there but I've heard the Southwest goes to 45 C (113 F) frequently in the summer. So humans being "evolved" enough to "cope" with 30-35 C heat isn't news.

      We can "cope" with it, we just damn well don't like it!

  14. Anonymous Coward


    "innovations such as clothing" But not for nvidia 480 users, it's far too hot :)

  15. Gavin McMenemy

    This isn't actually a new hypothesis...

    I studied this exact same idea when I was at Uni.

    To the Moderatrix...

    I hate to correct you but Soap (rather than soap-like materials) has been around since at least Celtic times. And there's plenty of evidence that grooming was very important to most early civilisations.

    Excessive washing is actually a very modern idea. Though there's been lots of beneficial side effects (human fleas are very rare these days) some others might not. My old microbiology lecturer suggested that one of the reasons we're smellier is because the stuff we obsessively put on our bodies kills off the bacteria that lives on our sweat. Which means we smell more... and so chuck more antibacterials on.

  16. Dave Murray Silver badge


    The boffins at Johns Hopkins clearly haven't seen a picture of me!

  17. Anonymous Coward
    Anonymous Coward


    I guess it depends on whether your species took to crossing the plains, or stayed in the shade of the trees. Evolution in action, gets rid of the old by removing head hair, thus causing sunstroke.

  18. Gordon Barret
    IT Angle


    Hmm - can I object to the use of the word "designed" in "humanity is actually designed to live in a scorchingly hot climate"?

  19. Anonymous Coward

    Sun Lizards

    Actually this might explain why so many people... like to be lounge lizards soaking up the sun's rays.

    Dark skin is more natural than white; who lack a pigment probably caused by evolution in colder climates.

    Living up in trees is more comfortable because the air will be slightly cooler due to shade... and so live the spiders for whom some have instinctive fear.

    Endurance running is definitely fun... although we have also savaged our bodies with malnurishment, poor nurishment, beef burger chemicals etc... and have not trained... that we become obese; sweat more and die early of heart attacks. Go barefoot; eat healthily (meat and vegetables) without E numbers and artificial rubbish... and get rid of this '3 meals a day' crap. Browse healthily on fruits and air dried meat and spot how much weight you put on. Probably a lot because the meat is stuffed full of hormones and crap fed to our animals...

    But if all this is really true then we should send all obese people to the great rift valley and get them endurance running. If they survive then our bodies are well adapted...

    1. DJV Silver badge

      Obese people

      "But if all this is really true then we should send all obese people to the great rift valley and get them endurance running. If they survive then our bodies are well adapted.."

      Yeah, but don't send 'em there all at once - else it would no longer be a valley - they would fill it to the brim and turn it into a saturated fat marsh.

    2. asiaseen

      Endurance running is definitely fun


  20. Paul Woodhouse

    I thought this was already accepted

    due to the fact that the nephrons in human kidneys are elongated to get the most water possible out of liquid that passes through them as in other desert animals...

  21. TonyHoyle

    The language is slightly annoying

    I see it a lot and it's not surprising there are so many creationists as a result.

    "humans .. shed their body hair in order to stay cool"

    This sounds like

    "Damn, I'm not. Let's shed my body hair. Oh look I've evolved."

    1. Anonymous Coward
      Anonymous Coward

      Paint me for a fool

      I for me don't for a moment believe that it's subtleties in language that caused the creationists to invent their fantasy-in-religion-sauce and start to foist it unto others. That they get away with stupid tricks like ``evolution is JUST a theory'' (emphasis added) means there are a lot of people Out There who can be easily conned with some cheap shots, but that alone won't have caused the movement.

      Rather, failure to discern between religion and science, failure at basic logic and critical thinking, caused by culture just as much as very low education standards, I'd blame for a much larger part in its popularity. Like how even British ``professors'' advocate ceasing to mark down students for bad spelling because it's too much work. The sheer gall to propose that, and by extension to refuse to pinpoint the real problem, is another sign on the wall.

      Then again, there is an element of science hoisting itself on its own petard. For one, though quite a lot has been said about scientific rigour and so on, actually teaching it mostly consisted of letting people ``get it'' by themselves. That in itself isn't so bad --certain monks use that all the time-- but without a barrier to weed out the clueless it is a problem. Increasingly so with the deluge of information and difficulty of reviewing it all. Hence the opportunity of some (certain Chinese publicist ``scientists'' come to mind) to game the review system. See also: _Cargo cult science_ by Feynmann.

      Then there is the newfangled communication methods that now also allow cranks, nutjobs, weirdos, kinks, and the most voluminous of all: the stupid and clueless, to easily find like minded (FSVO) people. They too flock and join up for a bit of mindless babble and prattle, and have their ideas and memes breed.

      To get out of the bind we need to improve the educational system so that the people with the capacity and talent to weed out cluefree information are taught how to do it, and to make it a habit to do it, too. Otherwise we'll keep on being stuck with ``concerned citizens'' managing to game school boards and push their pet religious and/or political agendas into millions of children's schoolbooks.

  22. IR


    how many people live there now, compared to everywhere else that is cooler?

    If you can't stand the heat, move somewhere colder.

  23. Subtilior


    So bald and sweaty people are more evolved then? Steve Ballmer will be glad to hear that.

  24. Anonymous Coward

    Ohhh bullshit

    Where I live 30*C is just a nice warm spring / autumn day..... 45*C is fucking stinking hot... 50*C is awful.

    And there are dessert type places that get to 50 - 60*C as a matter of course, and people live there as well.

    So where do these stupid professor types come out with this shit that 30*C is scorchingly deadly hot?

  25. Version 1.0 Silver badge

    A nice balmy 33C in Baton Rouge today

    Just thought you'd like to know. Mine's a decent glass of beer in the pool this afternoon ... and yes, I AM at work...

  26. Anonymous Coward
    Thumb Down

    This article is crap! CRAAAAAAAP!! --- FROM ME TO!

    Total rubbish. Where I live, in South India, 30C is our winter temperature. Let me just check the cat: what? Not walking upright? Still covered in fur? Goodness me.

    Sorry to AC for steeling your title: I couldn't think of a better one :)

  27. Anonymous Coward


    I evolved enough to turn on the air conditioner when it gets hot.

  28. Morpho Devilpepper

    What the future holds...

    Our distant descendents will be damp-skinned Alien Nation lookalikes...that is, if any survive the imminent takeover of the world by Skynet (formerly Apple Inc.)

  29. Mussie (Ed)

    cruelly hot ?

    "cruelly hot, generally above 30°C and sometimes above 35°C, for the whole time humanity has existed."

    cruelly hot..... Bah thats a ormal summer us LOL

  30. Steve Smith 2

    I feel special now!

    Gee whiz! "Scorchingly... cruelly... terrifically hot". 30°C+!

    I freaking wish! It's only 39°C outside now because it's not Summer yet. I'm going out for a smoke and expect I'll live to see another day.

    I think I'll do the Superior Dance while I'm out there, ye pale-complected pussies! ;-)

  31. Argus Tuft

    only in England

    30deg ... "Cruelly Hot".. Hah ha ha ha ha ha ha ha

  32. Anonymous Coward

    ...Leaky runners

    I seem to recall a story about one of the Leaky clan demonstrating our endurance by chasing-down an antelope, on foot of-course, during the day. Our grandpappy's exploited the empty niche of daytime hunters. Lazy lions and tigers snooze all day, oh my, exploiting the more popular twilight period. Others, like hyenas, can't be bothered to lift a paw until full night.

    This is an interesting report since it removes a show-stopper from the daylight hunter theory; that being that it wasn't all that hot and open in the area back then.

    Alas, my ancesters were captured by aliens, shaved, and anally probed. Since then, the family has been hair-shy, while also obsessed with porcelain and adorable, soft, fluffy, and flushable, kittens.

  33. John Tserkezis

    I must be smart.

    I'm bald, but heavily hairy across the rest of my body.

    By this hypothosis, my brain must be working so hard, it generates so much heat, it needs the additional heatsinking.

    That's my story and I'm sticking to it.

    So there.

  34. Anonymous Coward

    humans designed?

    One might say the article was designed to increase ad impressions, but that would be admitting that there was some intelligence behind it all...

    Ooh look, we're now a bit cooler than the koalas and kangeroos. Ah, bother, now I've got skin cancer.

  35. Robert Carnegie Silver badge

    Are most other posters politely ignoring the fact

    that on a web site self-described as "The Register is the one of the world's biggest online tech publications" (sic), this report concerning the lifestyle of our utterly techless, exclusively African ancestors is nothing but Lewis Page's Climate Change Controversion-o-the-Day?

    (And has anyone yet performed textanal to investigate whether Lewis actually is Andrew Orlowski with a toupee to disguise his identity and deficit of above-the-neck body hair, and another expense account? We've heard [Ed Reardon's Week] on Radio 4, we know the tricks. I'm imagining Lewis with a rather shaky Scottish Islander accent...)

    As for a mutation to lose hair - what could be easier? It is keeping the damn stuff that's difficult. Most of us have hair all over before we're born that disappears, called "lanugo" (some of us are born early still wearing it), which must have helped to give Haeckel the idea that Nature was making a chimpanzee and at the last moment changed its mind. And our controversial not-quite-gills. I've written software on the same design principle, assemble everything you could want and then output the material that you actually require. The Google Street View cars monitoring computer home networks evidently work that way, too.

  36. Triggerfish

    RE:Endurance predators

    African hunting dogs aren't endurance predators, not really they may chase for a while but if outdistanced they will give up, compare it to the San people in the Kalahari and they will literally chase an antelope down over the course of two our three days keepiing up the pace to the point where the antelpe literally collapses from exhaustion.

    Peccaries aren't predators, keep out of intense heat and stay near shade and water sources because of this, I would also guess that the hair might have the effect of warding of sunburn since they are pig family and a lot of pigs are sensitive to this.

  37. Anonymous Coward
    Anonymous Coward

    Hot or not?

    Where I live during most of the year (because my wife can't cope with British winter, and although I can cope I like it no more than she does) temperatures of 30 degrees plus at 3pm are quite common in midwinter. Sure, on the airport (which is where the official temperatuires figueres are measured and reported) and in other places right down by the sea temperatures are maybe a few degrees lower but a lot of people (including me) live a bit further up the hills where it's rather hotter. I've often sat in my front garden in temperatures above 40 degrees (there's usually a breeze, and humidity is usually low, so that's not unpleasantly hot). Coping with the heat is just a matter of drinking enough water and wearing the right clothes (and enough sunscreen until you buil enough tan to protect you, if you are going to be away from shade for a lot of time) - it isn't any big issue.

    A few years back I spent a couple of weeks in Southern Egypt. Afternoon temperatures typically 40 (or more) in the shade, but RH very low indeed so the heat wasn't a problem.

    Why does anyone think that people are not evolved to cope with temperatures above those of a miserable British spring? If a northener like me can cope with reasonable temperatures why can't people from the deep south of Britain (places like Manchester and Leeds) cope too? Is it just those from the effete south east who think 30 degrees is ridiculously hot?

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