The big brain

65


Discussion by: sylwin1
I have always been bothered by the same question.

Given that life has existed on this planet for 3.8 billion years (give or take a day or two) then why did evolution take nearly all that time to discover that the big brain was a clear winner in the survival stakes when it must have tried every other idea available to it during that time? As far as we know there is no evidence left to us from antiquity which says that any intelligent species ever existed before the hominids. Why not?

65 COMMENTS

  1. I think the correct answer would be that evolution does not have a conscious mind, therefore it doesn’t have a plan or set goals, it just happens. That being the case, it wouldn’t have ideas available to it, only the adaptations made necessary in order to survive. Perhaps a large brain wasn’t needed until hominids were forced to compete for dominance?

  2. then why did evolution take nearly all that time to discover that the big brain was a clear winner in the survival stakes when it must have tried every other idea available to it during that time?

    My goodness, is it that difficult to leave personifications aside? “when it must have tried every other idea” what ideas? what plan?

    • In reply to #2 by QuestioningKat:

      then why did evolution take nearly all that time to discover that the big brain was a clear winner in the survival stakes when it must have tried every other idea available to it during that time?

      My goodness, is it that difficult to leave personifications aside? “when it must have tried every other idea” what ideas? what plan?

      Sorry, careless wording. “How about you substitute the word possibilities for “ideas and plans”.
      I’m sure you must have grasped the point of the topic which had nothing to do with semantics.
      What a pedant!

  3. There’s a lot of costs involved in having a larger brain. A larger brain uses a lot more energy, so requires more high quality food. In our case there is also the high cost of difficult childbirth and a very long developmental path to adulthood.

    Individuals don’t need anything more (whether it be brain power, speed, strength, etc) than is necessary to survive and reproduce.

    A very rare window of opportunity obviously arose in our evolutionary history whereby the high costs of having a large brain became worthwhile.

  4. Big brain is not necessary for survival. All species have enough intelligence to survive with their specialized bodies. Humanoids are not really exceptional in any area except intelligence. We needed it to survive.
    Our ancestors learned tool making, learned to use fire etc. The more intelligent members survived and reproduced.

  5. What makes you think that a big brain ins the clear winner in the survival stakes ? All the evidence I see points to the fact that it’s a serious detriment. Currently we are hurtling towards an environmental disaster.

    In any case of the 3.8 billion year of life it seems 2.8 was spent getting to multicellular life. Nothing to do with brains.

    As far as we know there is no evidence left to us from antiquity which says that any intelligent species ever existed before the hominids.

    In what way do you think the dinosaurs were not intelligent ?

    Michael

    • In reply to #5 by mmurray:

      What makes you think that a big brain ins the clear winner in the survival stakes ? All the evidence I see points to the fact that it’s a serious detriment. Currently we are hurtling towards an environmental disaster.

      Michael

      Yes, the attributes of the big brain have not been equitably distributed among present day hominids as can be observed in certain locales e.g. Saudi Arabia, Pakistan, Texas, Utah, Idaho, North Dakota, Oklahoma and Alabama to name just a few.

      • In reply to #26 by godsbuster:

        In reply to #5 by mmurray:

        What makes you think that a big brain ins the clear winner in the survival stakes ? All the evidence I see points to the fact that it’s a serious detriment. Currently we are hurtling towards an environmental disaster.

        Michael

        Yes, the attributes of the big brain have not been equitably distributed among present day hominids as can be observed in certain locales e.g. Saudi Arabia, Pakistan, Texas, Utah, Idaho, North Dakota, Oklahoma and Alabama to name just a few

        I am European and so not familiar first hand with any of these places but they are Bible belt locations and I take it you mean that the people must be crazed by their religions to the dangerous extent of no longer being able to reason. Even so there must be plenty of people living in these places who are anxious to be rid of the local dominant religions. I tend to view them with more sympathy than you because they are surely just helpless and innocent victims of religion. There but for the grace of the devil go any of us.

        • In reply to #42 by sylwin1:

          In reply to #26 by godsbuster:

          In reply to #5 by mmurray:

          Yes, the attributes of the big brain have not been equitably distributed among present day hominids as can be observed in certain locales e.g. Saudi Arabia, Pakistan, Texas, Utah, Idaho, North Dakota, Oklahoma and Alabama to name just a few

          I am European and so not familiar first hand with any of these places but they are Bible belt locations and I take it you mean that the people must be crazed by their religions to the dangerous extent of no longer being able to reason. Even so there must be plenty of people living in these places who are anxious to be rid of the local dominant religions. I tend to view them with more sympathy than you because they are surely just helpless and innocent victims of religion. There but for the grace of the devil go any of us.

          Perhaps you ought to then familiarize yourself before commenting. I’m referring to regions where little girls get acid thrown into their faces by adult men. Where women in the 21st century are prohibited from driving. Where the universe is believed to be less than 10,000 years old. And perhaps it is abridged reasoning capacity which leads to religiousity in the first place .

          Here’s someone you’d hope would be “anxious to be rid of the local dominant religions” the Pakistani girl who got shot in the face by Islamists and recovered in a British hospital to which she was airlifted:

          “Today, you can see that I am alive. I can speak, I can see you, I can see everyone,” Malala said. “It’s just because of the prayers of people. Because all people – men, women, children – all of them have prayed for me. And because of all these prayers God has given me this new life, a second life.”

          Nary a mention of the specialized medical care, medical science: the medical skill of (and perhaps a thank you to) the doctors who performed the skull reconstruction, the cochlear implant technology which restored her hearing destroyed by the attack. My sympathy is with her plight, not with the crass stupidity of her belief in a religion that led to her plight in the first place. My derision is for those in the media who paralyzed by political correctness and the multiculti meme don’t have the backbone to point this out.

    • In reply to #5 by mmurray:

      What makes you think that a big brain ins the clear winner in the survival stakes ? All the evidence I see points to the fact that it’s a serious detriment. Currently we are hurtling towards an environmental disaster.

      In any case of the 3.8 billion year of life it seems 2.8 was spent getting to multicellular life. Nothing to do with brains.

      As far as we know there is no evidence left to us from antiquity which says that any intelligent species ever existed before the hominids.

      In what way do you think the dinosaurs were not intelligent ?

      Michael

      Hello Michael, Very good question so now we need to define “intelligence” and I haven’t the slightest idea how to do this. Maybe this would have made a better heading for this topic. All I know is that the dinosaurs didn’t have art, literature, poetry, chess, jet planes, science, Charles Darwin, computers and all the rest of it. Neither did they have any objective concept of the world they lived in, nor indeed did they have the capacity to even wonder about it any more than the possibility of life on other planets. This must be all assumed because I cannot know what the dinosaurs thought about! On the other hand they survived for about 160 million years and were therefore more successful than the hominids who, by comparison will only be here for a few minutes I’d say.
      Maybe the Dinosaurs did develop the big brain and instead of getting wiped out by an asteroid they went to war over territorial greed and did it that way.
      Keith

  6. A big brain is not a winner in the survival stakes. The hominids are pretty much extinct, only a handful of species left, and soon there will be only us, most likely. The beetles are enormously more successfull than the hominids, maybe millions of thriving species. This is the planet of the beetles, you just don’t notice because you’ve been living among hominids for too long.

    • In reply to #6 by Nigel S:

      A big brain is not a winner in the survival stakes. The hominids are pretty much extinct, only a handful of species left, and soon there will be only us, most likely. The beetles are enormously more successfull than the hominids, maybe millions of thriving species. This is the planet of the beetles, you just don’t notice because you’ve been living among hominids for too long.

      Explain to us please which is the correct criteria for “success” in the survival stakes.
      (1) Longevity of existence on this planet?
      (2) Sheer weight of numbers?
      (3) intellectual dominance no matter how long it lasts?

      sylwin1.

      • In reply to #34 by sylwin1:

        In reply to #6 by Nigel S:

        A big brain is not a winner in the survival stakes. The hominids are pretty much extinct, only a handful of species left, and soon there will be only us, most likely. The beetles are enormously more successfull than the hominids, maybe millions of thriving species. This is the planet of the beetles, you just don’t notice because you’ve been living among hominids for too long.

        Explain to us please which is the correct criteria for “success” in the survival stakes.
        (1) Longevity of existence on this planet?
        (2) Sheer weight of numbers?
        (3) intellectual dominance no matter how long it lasts?

        sylwin1.

        There is no “correct” criterion when measuring success. It just depends on which argument you’re trying to win.
        It just can’t be a sensible comparison when talking about numbers of beetles or algae and trying to compare humans with them in terms of quantity. That is a silly one.

        • In reply to #51 by sylwin1:

          There is no “correct” criterion when measuring success. It just depends on which argument you’re trying to win.

          Agreed. You’ve just answered your own question and made me wonder about the second sentence you’ve added there…

  7. Why stop at 3.8 billion years, why not 10 billion?

    There is no ‘why’, it is just what it is. It could as well have taken a billion year, or 10 times that for all we know. Life is tough, life gets rebooted once in a while, extinction happens, survivors evolve different strategies to exploit the gaps.

    Big brains also are not a ‘clear winner’. Look at arthropods, bacterias, algaes, viruses, they’ve been around since the very beginning, and will probably outlive us all. They may be looking like lower forms of life to you, but they are perfectly adapted for their survival.

    Besides, we don’t know enough about cognition, consciousness and the brain’s higher functions to make any conclusive claim about its evolution. And yes, there were other species. At least close relatives that might have evolved along a different path given the chance. They were the Neanderthals, and possibly other earlier hominids that somehow didn’t make it.

    • In reply to #7 by papa lazaru:

      Why stop at 3.8 billion years, why not 10 billion?

      There is no ‘why’, it is just what it is. It could as well have taken a billion year, or 10 times that for all we know. Life is tough, life gets rebooted once in a while, extinction happens, survivors evolve different strategies to exploit the gaps.

      Big brains also are not a ‘clear winner’. Look at arthropods, bacterias, algaes, viruses, they’ve been around since the very beginning, and will probably outlive us all. They may be looking like lower forms of life to you, but they are perfectly adapted for their survival.

      Besides, we don’t know enough about cognition, consciousness and the brain’s higher functions to make any conclusive claim about its evolution. And yes, there were other species. At least close relatives that might have evolved along a different path given the chance. They were the Neanderthals, and possibly other earlier hominids that somehow didn’t make it.

      The fact is I don’t know which species has won the survival stakes. At different times it may have been different ones. Everybody seems to think that if you count years of longevity or the population of a species we can arrive at a winner that way. Well there are other ways of measuring success. The first thing to do is figure out what you need to be good at to win the survival stakes and in the evolution tournament the trick is to eliminate (kill) most if not all of your competitors. The more you get rid of the easier it is to survive because the reward is an easier, more comfortable and richly rewarded lifestyle and very little danger from predators. I submit that right now, like it or not, the hominids are hands down winners and they have managed to do it with the big brain.
      If their success is measured in longevity they will be surely dismal losers. If measured in growth of population they will be winners (because their numbers cannot be reasonably compared with algae and viruses). But measured in tournament terms they are massive winners.

  8. Evolution does not “try out ideas”, it builds incrementally on what is already there. There is no way for evolution to “know” that something is a clear winner until it exists. We exist, and we seem, perhaps, to be winning, at least for the moment. But every species which exists right now is also a “winner”, and every species which is thriving today is a “clear winner” (ants, cockroaches, and rats all come to mind).

    Evolution can only build in tiny increments on what is already there. Before you can have human brains, you need almost-human-ape-brains. And before that, you need not-quite-as-human-ape-brains… and so on before that you need primitive-mammal(rodent like?)-brains… long before that you need reptile-brains, fish-brains, worm-brains. Before that, you need multi-cellular organisms. Before that you need cells themselves to evolve from molecular evolution.

    Since the Earth is the only example we have, there is no way to guess whether human-level intelligence has evolved quickly or slowly as compared to evolution on other planets. Maybe the reason that we have not detected alien intelligence is that humans are the first intelligent life in our galaxy, maybe the first within the observed universe. After all, somebody has to be first. Maybe, on average, it will take other Earth-like planets 10 billion or 20 billion years to evolve intelligent life, and maybe other less Earth-like planets take even longer, if they support life at all.

  9. One way of looking at this may be that some “solutions” to the “survival problem” (=hypothetical organisms) are really hard (or downright impossible) to be reached by evolution. If the benefit of attaining some feature shows only in the long run, after it is evolved well enough, this feature will never be attained, because evolution is inherently blind. It makes only small steps. So if some “solution” is separated from the existing solutions by a “potential barrier”, which is too high, this solution is practically unreachable. As I imagine it, we first needed the right change of environment to push us in the right direction. Back in the days in Africa, we were forced to leave trees for savannas. Having no big teeth or fast legs, we were very vulnerable and had nothing but our brains to rely on, which put pressure on its performance. But even then it was no clear win, I think we were even on the brink of extinction a couple of times. The potential barrier of complicated birth, high energy consumption and slow development was almost high enough to prevent us from reaching the other side (learning how to do good tools, cooperate in larger groups, win). Even today, we probably represent some miserable “local maximum” with respect to fitness in the space of all possible organisms. There are most probably creatures far superior to us, which happened not to have evolved and which will never evolve.

  10. Big brains are a clear winner? So are cancer cells, until the effects catch up with them.

    Fact is, bacteria have always been the most successful organisms on the planet. We multicellular specimens are just a bizarre side show.

    As for actually evolving large brains, it has to be both a possible avenue for the particular form and advantageous to their survival. A crocodile isn’t going to benefit from a large brain, nor will it be able to feed it adequately. A bird will not be able to juggle a large brain and flight at the same time.

    Insects don’t even need a brain. I found a headless emperor dragonfly once, and it was still alive. I picked it up and it clung to my finger, then actually took flight. It immediately crashed, of course, because it couldn’t see where it was going.

  11. The big winner in the “survival stakes” is bacteria ~ not known for chess aptitude nor poetry

    Go down to your local supermarket. Buy some live yoghurt & ask it to introduce you to its friends ~ you might as well get to know the bacteria on first-name intimate terms because for every cell in your body with your DNA there are 10 cells keeping you alive that DO NOT contain your DNA & they’re relatives of your yoghurt mates. They keep you alive & they’ll eat you when you’re dead.

    Survival stakes? Phhhht!

  12. What kind of intelligence do you means? I don’t think it is limited to hominids (orangutan, gorilla, human, chimpanzee, bonobo) among the Primates. Other mammals who are no slouches ate the Cetaceas, The Corvids (crow, raven, etc.) also have impressive intelligence. Their “total brain-to-body mass ratio equals that of great apes and cetaceans, and only slightly lower than in humans” (wikipedia). Given that birds descend from the dinosaurs, it makes one wonder what might have been going in in the heads of some of them, esp. the predators.

    If you get turned loose in Amazonia or Africa with no chance of contact with the outside world, no clothes, no tools, no knowledge or much of anything, and a woman to keep you company (and burdened with offspring), and told to make a go of it, I think a lot of the capabilities of your big brain might become unnecessary and you’d be willing to trade them for a better senses of smell and hearing, feet that were better for climb trees, and a little more fur. You wouldn’t be in a rush for general relativity or quantum mechanics.

  13. That is a fair question. Let me ask you this:

    1) What makes an organism a winner?

    2) Is it possible to be a winner without a large brain?

    Aside from this though I think you ask a fair question. Part of the answer may be that there were many key developments that had to occur first. To develop human-level intelligence many key innovations had to occur first. For example:
    Homeothermy (without being able to maintain a higher-than-ambient body temperature, high levels of of intelligence would not evolve.
    Intelligence is highly favored in social organisms, so sociality would be a key evolutionary innovation.
    Bipedalism in humans allowed us to use our hands for tasks outside of locomotion (allowing us to perform tasks that required (and favored) larger brain size.

    These are just a few of the key innovations that allowed for the evolution of human-level intelligence.
    Are we the clear winners? You tell me. I hope this helps.

  14. Evolution has neither direction nor purpose – and the evolution of large multi-cellular organisms with high metabolic rates required as a minimal precondition, the presence of (relatively) large amounts of free oxygen. That took a LONG time to build up. THEN once large multi-cellular organisms with differentiated organs, including nervous systems evolved the next step was to get to land.

    Once on land, and remember with neither direction nor purpose involved an animal had to evolve with the right characteristics to 1.)USE a large brain to make technology and 2.)selection pressures that forced that organism to develope a BRAIN instead of claws or fangs or poison or the ability to run really fast or fly etc.

    The great apes had a number of characteristics that made using a large brain to build things possible. From a ball and socket joint at the shoulder to opposable thumbs to rotateabe writs — the combination of all those traits — which only the brachiting great apes possess — makes it possible for humans to perform complex manipulations of objects using both hands in front of our bodies where we can see them.

    Which brings us to binocular, color vision with excellent depth perception AND the ability to rapidly shift focus from near to far.

    And of course somewhere along the way walking upright so those hands could be free to carry things.

    But still, even with all of that our ancestors stayed apes, It was the crucible of the widening East African Rift Valley plus serveral rapid glacial advances and retreats leading to (realtively) rapid changes in climate in East Africa from forest to grasslands, back and forth several time — i.e., intense adaptive pressures, that seemed to have 1. Led to the development of modern man AND 2. damn near drove him to extinction at the same time.

    That’s a really, really brief sketch. It took the confluence of the right animals in the right place coupled with intense evolutionary pressure to finally produce an animal that had no claws, no teeth, could not out run anything (endurance is another story, but that doesn’t help outrun predators), too big to fly — but which lived in social groups and had the basic equipment to synergestically give a big problem solving brain a chance to find ways to compensate for those other shortcomings.

    Before primates, no other animal had full color vision and eyes in the front of its face giving it the ability to not only have depth perception, but depth perception of objects close to its face.

    Before the great apes, no animal had grasping hands attached to arms capable of the vast range of motion of the great apes.

    Before the Pleistocene, there had never been enough evolutionary pressure to force any great ape to develop a really big brain as its only available evolutionary option to survive.

    And remember, this all had to happen with no direction, no plan, no external nudges from any experimenter manipulating genes or circumstances.

    What is fascinating is NOT that it took so long for man to appear but rather the perfect set of circumstances ever came together to produce him at all.

    And like I said, those circumstances were so severe that they damned near killed man as soon as he had evolved. But that’s another story.

  15. Besides the excellent points above, I’d like to add a reminder that, while a species may benefit from having smart members, evolution only induces those changes which benefit the individuals in which they occur or their relatives. Having a big brain has plenty of costs, all paid for by the individual.

    Why did humans get it? Perhaps a better question, given what the fossil record indicates, is why our brains expanded so quickly once they began to expand. The consensus (I think it’s a consensus, anyway) is that this acceleration is a result of hand-brain co-evolution providing a positive feedback into the selection coefficients. Once our ancestors became bipedal, our hands moved from tool-use/locomotion hybrids to tool use specialism.

    Why in turn did bipedalism, which is rare, happen in us? Because we had to adapt to losing a rainforest, with our new environment, full of reeds, encouraging bipedalism to reduce energy consumption.

  16. You’re assuming that big brain is the ultimate format for a species, this isn’t true.

    Sure, humans need big brains, but that is just one niche, insects, fish, rodents etc all fill other niches that would not be improved by having bigger brains, since bigger brains use more energy, make birthing harder for mammals, weigh more etc.

    Even in humans it is not clear that we need bigger brains than we have now… we might evolve to have smaller ones… Neanderthals had bigger brains than us.

  17. Given that life has existed on this planet for 3.8 billion years (give or take a day or two) then why did evolution take nearly all that time to discover that the big brain was a clear winner in the survival stakes when it must have tried every other idea available to it during that time?

    There is no reason to believe this.
    Millions of other organisms exist in greater numbers than humans on Earth. – Many of them have survived here for much longer than human or mammals.

    There is no reason to believe humans with big brains are long term “winners”. We are changing the planet at unprecedented rates. Extinctions have happened before. Many other species are much better placed to survive radical environmental changes.

  18. There are some fairly intelligent animals around. And lots of biggish brains. So intelligence might not be a key factor for leaving evidence – at least in the form of technology artifacts.

    It’s not outright CPU power that matters. It might be similar to smartphones: software quality, battery life, memory capacity and performance, screen resolution, and audio quality also count. Plus having a good network with extensive coverage and availability.

    Just as with smartphones, it isn’t possible to evolve tremendous processing capacity or you’ll find the batteries go dead shortly after breakfast time. So it probably isn’t possible for any animal that eats normally available food to be extremely much more intelligent than most other animals. There are limits within which normal variation implies some degree of overlap with other species at the extremes. There are certainly examples around of some living humans who seem to be be less intelligent than their own pet dogs.

    Humans are unusual in combining intelligence with several other exceptional characteristics: upright posture, tremendous mobility and efficiency (owing to bipedal locomotion), manual dexterity and load carrying capacity (also owing to upright posture), incredible endurance (owing to sweating and fat metabolism), complex language and social cooperation, empathy, self control, and forward planning, and practices like longevity, grand-parenting, and innate gullibility during youth which enables rapid absorption of crucial information across generations without direct personal experience. Intelligence is a consequence of all these things developing under selection pressure.

    So there’s multiple other highly unlikely accidents of history required along with high intelligence. And as is obvious, present day people only need to possess a majority of these various human capabilities to operate reasonably well, given the absence of selection pressure which allows intelligence be be optional. So intelligence won’t be an obvious clear winner in distant future generations.

    And if human-like intelligence has perhaps emerged previously there might be a simple explanation for the lack of antique evidence:

    Humans have probably been intelligent for many 10’s of thousands of years. Probably linked to changes in food sources from mostly plants to scavenging meat and using stone, wood, and fire. Only relatively recently has a substantial human population emerged that’s capable of leaving widespread evidence of technology detectable by future archaeologists. And most of that is limited to tiny bits of charred wood, middens of bones and shells, and stone tools – basically just rocks. Our more recent sophisticated industrial technology hasn’t been around long enough to leave much of a trace discernible by future scientists in a million years time. Anything metallic wouldn’t survive anyway. And pretty much all the major artifacts of our modern agricultural civilisation are located on flood plains. Chances are that all this will be swept away during multiple glacial periods in due course. All that would be left of our present civilisation would be the scattered remnants of a few stone tools, originally installed in display cases of hand axe collections in museums here and there.

    So even if human-like civilisation had arisen millions of years previously, including attaining advanced technology, then we wouldn’t necessarily notice its traces today. Even if it closely resembled our own modern lifestyle. And if previous civilisations didn’t resemble our own expectations then we might not even recognise its legacy if we stumble across it.

    Given that our civilisation has become technically sophisticated so recently then there may similarly be only a very brief period during which any preceding advanced civilisation remains in this goldilocks era of industrial global warming and nuclear weaponry phase we’re currently enjoying. Perhaps we might not even be around not long enough to leave much of a trace for future archaeologists to dig up. Very intelligent and technology astute creatures might have previously determined that they could be better off becoming less intelligent and less industrialised. It’s reasonably to assume that they would have possessed the capability to genetically engineer their species into this more sustainable situation. Say, as rats or mice. But with an enhanced sense of humour and capacity to enjoy life.

    Such projects could be done quite rapidly via selective breeding supported by government subsidies instead of genetic engineering. Supporting evidence for this is that you can see this happening already now to some extent with the sheer number of stupid people around who are prolific breeders at public expense. Further support for this theory might be found if it were eventually established that mice had more of a sense of humour than could be explained by natural evolution.

  19. To simplify it for you, it’s all about suitability to the environment. Evolution is basically a series of genetic mutations, if a mutation is beneficial to its host, then the host can extract more from its environment and the mutation is passed to the next generation. If over generations more and more beneficial mutations occur then you have a highly specialised host, this can be a pitfall if the environment changes more rapidly than the beneficial mutations. In the early life of the planet there were many cataclysmic events which led to mass extinctions, probably only leaving some relatively simple organisms. Hominids evolved in a fairly stable environment during a relatively stable time in the earth’s history, mutations of the brain which led to social co-operation were benificial, provided more food and allowed more free time to develop easier methods to harvest more food, those mutations survived and were amplified. We may not have found dinosaur chess boards, but they were wiped out by a very sudden and extreme event, if that had not been the case perhaps we would be sitting here now discussing the cholesterol levels of mice vs. birds.

    Just an aside, if you really think we are that much different to any other animal, take a trip down any high street or nightclub district at 3am and you will see the same basic survival problems that face those animals with “lesser” brains being faced by the current hominid model – Can I eat it? Can I fuck it? Will it eat me?

  20. There is the possibility that when the ability to use tools (bipedal locomotion combined with freedom to use hands and the opposable thumb) gave a selective advantages to increased brain size in certain lines of evolution. The other species in the past where intelligence did not evolve to the extent of humans was due to their evolutionary development of body parts that did not give higher intelligence an advantage.

    Another development that may have influenced the increase of intelligence was speech. The ability to communicate complex concepts went well with the development of the use of tools and increase of intelligence.

    Note…I don’t think that brain size per se correlates very well with the level of intelligence of a species.

    • In reply to #24 by cbrown:

      There is the possibility that when the ability to use tools (bipedal locomotion combined with freedom to use hands and the opposable thumb) gave a selective advantages to increased brain size in certain lines of evolution. The other species in the past where intelligence did not evolve to the extent of humans was due to their evolutionary development of body parts that did not give higher intelligence an advantage.

      Another development that may have influenced the increase of intelligence was speech. The ability to communicate complex concepts went well with the development of the use of tools and increase of intelligence.

      Note…I don’t think that brain size per se correlates very well with the level of intelligence of a species.

      I certainly agree with your comment about speech. An interesting experiment would be for an engineer to invent a sophisticated voice box which could then be implanted into a chimpanzee. What do you think would happen once the whole species had them. Ten thousand years leter would they have evolved any Einsteins?
      Just a thought!

  21. Evolution is not trying to reach the best solution, or more worthy solution. In fact evolution has no long term goals at all, it is not a conscious thing, it is has no more goals than a winter storm.

    Life is subject to naturally occurring RANDOM mutations.Most of these mutations are not beneficial. The few random mutations that are beneficial because the non-random gatekeeper known as death passes them through are the only ones that are passed on. Note that the only criteria is the organism survives, not that it is “better”.

    A big brain is NOT a clear winner in the survival game. There are more bacteria than humans. There are more insects than humans. There are more algae than humans. There are more plants than humans.

    Through a combination of blind luck, changing environment, and having a comet or asteroid wipe out the dinosaurs and allowing mammals to flourish we came about. There is no evidence that big brains are the best bet for survival. Humans have been around for less than 10,000 years, a blink compared to other successful species.

    We are not special. We are not evolutions goal.

  22. Evolution isn’t a conscious being that’s trying out better and better species, that fact that we consider ourselves the dominant species on earth is besides the fact, why dose it take a star for example billions of years to begin producing heavier elements such as iron which in turn cause the star to explode. Its taken billions of years for humans to reach a stage were we’re a treat to the survival of the planet. Evolution doesn’t have ideas or plans neither do stars.

  23. Big brains doesn’t count so much from individual to individual and on a day to day basis, as intelligent people tend to live their lives with curiosity, but they don’t do much with it. They just walk around reading and studying, nothing productive comes from it. But if an intelligent human gains political control over a large group and he uses his brain to wage smart war against another large group of people, big brains can eliminate the other group entirely through smart warfare, and so a big brain can in this situation lead to the survival of the entire species the smart fella belong to.

  24. It’s an interesting point, but I think evolving the human brain didn’t really take as long as it seems like. Sure, life has been around for 3.5 odd billion years, but fully three billion of that was just bacteria and stuff. Complex multicellular life really only showed up about 500 million years ago at the beginning of the Cambrian, so animals have really only had half a billion years to evolve human intelligence.

    Naively, this would seem to suggest that it is harder to evolve complex multicellular life (three billion years or so) than it is to evolve human-level intelligence given multicellular life (0.5 billion years). That’s food for thought, although it’s also possible that some limiting environmental factor changed 500 million years ago to make it possible.

  25. I have asked the same question on this website several times before after contributors seem to be stuck in the same old groove citing weight of numbers as the only measure of success, or millions of years of longevity. How about adding a third which would be total dominance to the point of wiping out all other competitors except the useful ones? It seems to me that if evolution has ever had a goal then this is it.
    I submit this as measurement number three.
    Sylwin 1

    • In reply to #35 by sylwin1:

      I have asked the same question on this website several times before after contributors seem to be stuck in the same old groove citing weight of numbers as the only measure of success, or millions of years of longevity. How about adding a third which would be total dominance to the point of wiping out all other competitors except the useful ones? It seems to me that if evolution has ever had a goal then this is it.
      I submit this as measurement number three.
      Sylwin 1

      while humans have caused extinctions of other species, this is not an intention so much as a consequence. you could say left handed chirality already holds that title by a margin of billions of years

      “usefullness” is impossible to define as you only know how useful something is when you’re forced to consider it’s demise

      you can also look at the species that have been domesticated. they have evolved to exploit humans and managed it with smaller brains, then there are all the accellerations in bacterial evolution that humans have caused, and looking further forward it’s impossible to count how many new species will evolve because of human activity.

      don’t make the mistake of thinking there’s anything special going on. this may be the anthropocene but that’s just a way of describing how humans are shaping the planet right now. a far more effective way of becoming dominant is to be hardy enough to fill the environmental niches left when other species suddenly go extinct. a big asteroid is as useful as a big brian for that, or maybe a local GRB.

      big brains have made a niche for one type of ape. the loss of other species is a consequence of a very recent populaiton explosion. big brains helped this through farming, arranged breeding, industry and antibiotics. these have damaged the environment in a way that will bring the species back into some sort of balance soon.

      by your analogy the most successful maggot on a pile is the one at the top at the moment you look and ask the questoin. it got there by chance and it’s going to roll down any second.

      brains are handy. if they’re big enough to move the species to a new planet, then I’ll accept something special has happened in human evolution but other than that you can always say humans are the top species as long as you invoke human standards as the measure

    • In reply to #35 by sylwin1:

      I think there is a genuinely interesting question at the heart of your posts, which is that as brain to body ratio goes, or outright intelligence, or imaginative thought goes, homo sapiens is at the top of the pile. And by a distance. The question is, I assume, why this should be? Why have there been no other animals which have developed ‘thinking’ as an attribute to the extent that we have, and by what process did the evolution of this occur?

      I also think you’ve been given some decent answers to this. There is decent evidence, I believe, that bipedism preceded increased manual dexterity, and that this increased capability was a driver for brain growth. There is also an argument that sexual selection played a part in stimulating brain expansion in hominid species (i.e. intelligence became a characteristic for a prospective sexual partner). The flaw with this argument is that sexual selection is normally the ‘choice’ of one sex, not both, and sexual selection therefore leads to sexual dimorphism in regards to that attribute.

      However, I think you are getting sidetracked by imagining evolution having a goal. Your error here has been pointed out, so I’m not sure why you keep re-stating it. It is not a useful way to approach questions of evolution.

      A slightly different way of looking at this question does interest me. If we accept Sylwin’s implied definition of ‘human-like’ intelligence, which I think we’d have to agree is different from other intelligent animals, why, given the much longer span of time available, did reptilian life never find an evolutionary niche into which this intelligence fit? The evolution from mammals, to ape-like animals, to humans (with the associated increases in intelligence) was a comparatively quick (in evolutionary terms) process.

      • In reply to #38 by bob_e_s:

        In reply to #35 by sylwin1:

        I think there is a genuinely interesting question at the heart of your posts, which is that as brain to body ratio goes, or outright intelligence, or imaginative thought goes, homo sapiens is at the top of the pile. And by a distance. The question is, I assume, why this should be? Why have there been no other animals which have developed ‘thinking’ as an attribute to the extent that we have, and by what process did the evolution of this occur?

        I also think you’ve been given some decent answers to this. There is decent evidence, I believe, that bipedism preceded increased manual dexterity, and that this increased capability was a driver for brain growth. There is also an argument that sexual selection played a part in stimulating brain expansion in hominid species (i.e. intelligence became a characteristic for a prospective sexual partner). The flaw with this argument is that sexual selection is normally the ‘choice’ of one sex, not both, and sexual selection therefore leads to sexual dimorphism in regards to that attribute.

        However, I think you are getting sidetracked by imagining evolution having a goal. Your error here has been pointed out, so I’m not sure why you keep re-stating it. It is not a useful way to approach questions of evolution.

        A slightly different way of looking at this question does interest me. If we accept Sylwin’s implied definition of ‘human-like’ intelligence, which I think we’d have to agree is different from other intelligent animals, why, given the much longer span of time available, did reptilian life never find an evolutionary niche into which this intelligence fit? The evolution from mammals, to ape-like animals, to humans (with the associated increases in intelligence) was a comparatively quick (in evolutionary terms) process.

        I don’t believe that that evolution has any goals and apologise for any inference to the contrary. What I would say is that evolution forces a goal on each of us as individuals and that goal is to find a way of surviving by becoming better at it than our competitors, even if it means killing as many of them as possible. (Like the Lions and Hyenas). I am convinced that the attribute which triggered the evolution of the “big brain” was the development of speech. I would say that this is the one thing which separates hominids from the rest of creation and must have led to toolmaking and agriculture. After this development the exchange of ideas was possible and eventually the recognition of various concepts which then could grow in complexity.

        sylwin1

        • In reply to #43 by sylwin1:

          I am convinced that the attribute which triggered the evolution of the “big brain” was the development of speech. I would say that this is the one thing which separates hominids from the rest of creation and must have led to toolmaking and agriculture. After this development the exchange of ideas was possible and eventually the recognition of various concepts which then could grow in complexity.

          Have you researched this anywhere? There are a number of very good books on human evolution which will enlighten you on why you’re wrong about this. Homo Ergaster had a brain much more complex than any other animal (apart from Homo Sapiens), were capable of making tools and there is evidence they had a social structure. Yet the common consensus is that they were not capable of speech. And the reason is that a number of physiological adaptions required for speech had not happened.

          And you are still talking about evolution in terms of ‘winners’. I don’t think you’ve got the process clear in your mind.

        • In reply to #43 by sylwin1:

          I don’t believe that that evolution has any goals and apologise for any inference to the contrary. What I would say is that evolution forces a goal on each of us as individuals and that goal is to find a way of surviving by becoming better at it than our competitors, even if it means killing as many of them as possible. (Like the Lions and Hyenas). I am convinced that the attribute which triggered the evolution of the “big brain” was the development of speech. I would say that this is the one thing which separates hominids from the rest of creation and must have led to toolmaking and agriculture. After this development the exchange of ideas was possible and eventually the recognition of various concepts which then could grow in complexity.

          There are two key features which give a survival advantage to animals with big brains, the ability to communicate and work in co-operative groups;- (particularly in the case of predators.- wild dogs, lions, dolphins etc ) . . . . .. and tool use.

          Both of these features have been found to be much more prevalent in intelligent non-human animals, than was thought in the past!

          While humans are masters of these skills, they should not be under-rated in other animals.

      • In reply to #38 by bob_e_s:

        In reply to #35 by sylwin1:I think there is a genuinely interesting question at the heart of your posts, which is that as brain to body ratio goes, or outright intelligence, or imaginative thought goes, homo sapiens is at the top of the pile. And by a distance. The question is, I assume, why this should be? Why have there been no other animals which have developed ‘thinking’ as an attribute to the extent that we have, and by what process did the evolution of this occur?I also think you’ve been given some decent answers to this. There is decent evidence, I believe, that bipedism preceded increased manual dexterity, and that this increased capability was a driver for brain growth.

        There is also an argument that sexual selection played a part in stimulating brain expansion in hominid species (i.e. intelligence became a characteristic for a prospective sexual partner). The flaw with this argument is that sexual selection is normally the ‘choice’ of one sex, not both, and sexual selection therefore leads to sexual dimorphism in regards to that attribute.

        However, I think you are getting sidetracked by imagining evolution having a goal. Your error here has been pointed out, so I’m not sure why you keep re-stating it. It is not a useful way to approach questions of evolution.A slightly different way of looking at this question does interest me. If we accept Sylwin’s implied definition of ‘human-like’ intelligence, which I think we’d have to agree is different from other intelligent animals, why, given the much longer span of time available, did reptilian life never find an evolutionary niche into which this intelligence fit? The evolution from mammals, to ape-like animals, to humans (with the associated increases in intelligence) was a comparatively quick (in evolutionary terms) process.

        I think in the large brain stakes we also overlook the sheer strength of natural selection and the fact we’d started off down a very non specialist route so all we really had on our side was brain power. If you look at all the branches of our particular route in evolution since we diverged from chimps, they are all are dead so it would appear that rapid evolution of brain power was very important to bipedal primates survival. As others have said we needed to out compete and that was starting to be all our group had.

        Australopethicus Afarensis was bipidal yet still retained the features of tree dwelling suggesting a very changeable environment. Changeable environments require rapid adaptation to survive so we already seemed to be trading specialisation for adaptability. With sexual selection there is always a trade off which puts a natural break on changes (peacocks tail is limited by need to stand up for example). For a big brain that trade off is difficult childbirth and the fact they are expensive in terms of energy usage. That makes it a much weaker theory in that further growth would easily have been wiped out at an earlier point by that trade off if there weren’t other significant survival advantages outweighing it.

        It might be simply down to being forced out of our comfy niche in the trees and then having to rapidly adapt to a harsh environments which would have required a more complex alternative evolutionary route to just enlarging brains. In short given we were already primates, it was probably the only thing evolution could do quickly to ensure survival under the circumstances.

        And far from being a clear winner, for most of that time it doesn’t seem to have been, none of our near cousins and ancestors made it, and its probably sheer fluke that we did. After all, it is only relatively recently that its allowed us to dominate and we are the only ones for whom it really worked as a sole strategy, poor old neanderthals didn’t quite make it.

        So why did evolution take so long to deveolop big brains? Probably because they aren’t that efffcient in the short term, which is all evolution really deals with, and other routes are more sucessful. Maybe with us it was just the easiest or only route it could take and once started we were so ill adapted in other respects that every single increase gave us such a large advantage of just a tiny bit more of an understanding of our environment and a tiny bit more time learning that natural selection kicked into overdrive?

    • In reply to #35 by sylwin1:

      I have asked the same question on this website several times before after contributors seem to be stuck in the same old groove citing weight of numbers as the only measure of success, or millions of years of longevity. How about adding a third which would be total dominance to the point of wiping out all other competitors except the useful ones? It seems to me that if evolution has ever had a goal then this is it.
      I submit this as measurement number three.

      Fine, but you’re conflating different issues then. There’s not three, but countless ways in which you can measure success; survival is one, dominance is another. In the OP you raised the issue of survival, which by defintion is an exercise in not dying, or from a species’ point of view: not dying out. And for that big brains have a lousy track record; almost all the species that have tried that particular trick are dead and gone.

      Dominance is nice too, but evolution only cares about that insofar as it’s a useful engine for survival. It probably is, and we achieved it because of big brains, so it might seem like big brains is the obvious way to go, but that’s nothing but hindsight bias. Big brains is a strategy for survival in the same way buying lottery tickets is a strategy for getting rich; it almost certainly won’t be worth the cost. So I don’t think your question “why in the world hasn’t this happened before?” is a very sensible one. With its extreme unlikelihood of happening, and with the mass extinctions, the dinosaurs, the ice ages and everything, I have no idea whether it happened very slow or very fast or somewhere in between. I mean, how long does it usually take?

  26. why did evolution take nearly all that time to discover that the big brain was a clear winner in the survival stakes when it must have tried every other idea available to it during that time?

    clear winner by who’s standards? how do you define “every other idea”?

    the clear winner is simplicity. over 90% of the biomass on earth has less than 2 cells. micro-organisms frozen for hundreds of thousands of years can be revived. most of the multi-cellular life on earth has no brian.

    your big brain might be a clear winner when it comes to keeping you alive but don’t think evolution holds you in the same esteem

    • In reply to #36 by SaganTheCat:

      why did evolution take nearly all that time to discover that the big brain was a clear winner in the survival stakes when it must have tried every other idea available to it during that time?

      clear winner by who’s standards? how do you define “every other idea”?

      the clear winner is simplicity. over 90% of the biomass on earth has less than 2 cells. micro-organisms frozen for hundreds of thousands of years can be revived. most of the multi-cellular life on earth has no brian.

      your big brain might be a clear winner when it comes to keeping you alive but don’t think evolution holds you in the same esteem.

      Yes it does!
      But only over the time it takes before extinction wipes us out. Even then you cannot know whether the big brain will solve the problems it causes because the hominids are not finished yet.

      Granted it doesn’t look good

    • In reply to #39 by exReligiousNut:

      Is there any truth in the lost civilizations of the Atlanteans or Lemurians or is that just hocus-pokus?

      After the last ice-age the sea-levels rose world wide, drowning many coastal plains and inhabited areas. This would cause numerous population movements, as hills became islands, and populations were forced inland.

      The world’s oceans have risen about 100 metres in the last 20,00 years, giving rise to various flood myths.
      http://www.giss.nasa.gov/research/briefs/gornitz-10/

      In addition to this local lands and coasts, may have risen or fallen due to crustal movements.

      There have also been local floods where rising waters have spilled over rock dams to inundate land which was previously dry, but below sea-level (as the Dead Sea is today). The Black Sea Basin is one of those areas.

      The Atlantis Myth is probably from the Thera Volcanic explosion. http://en.wikipedia.org/wiki/Thera-eruption

  27. I wouldn’t trade away our big brains, that said, we aren’t the fastest, strongest, don’t have the best memories, the best eyes, the best smell, etc. etc. If we were evolved as the best in everything that would be something. Was wondering the other day if we have the greatest difference between our average intelligence and our smartest and brightest. I’m not so sure our average is so much greater than other species. Just enough to do a few neat tricks.

  28. In reply to #50 by godsbuster:

    In reply to #42 by sylwin1:

    In reply to #26 by godsbuster:

    In reply to #5 by mmurray:

    Yes, the attributes of the big brain have not been equitably distributed among present day hominids as can be observed in certain locales e.g. Saudi Arabia, Pakistan, Texas, Utah, Idaho, North Dakota, Oklahoma and Alabama to name just a few

    I am European and so not familiar first hand with any of these places but they are Bible belt locations and I take it you mean that the people must be crazed by their religions to the dangerous extent of no longer being able to reason. Even so there must be plenty of people living in these places who are anxious to be rid of the local dominant religions. I tend to view them with more sympathy than you because they are surely just helpless and innocent victims of religion. There but for the grace of the devil go any of us.

    Perhaps you ought to then familiarize yourself before commenting. I’m referring to regions where little girls get acid thrown into their faces by adult men. Where women in the 21st century are prohibited from driving. Where the universe is believed to be less than 10,000 years old. And perhaps it is abridged reasoning capacity which leads to religiousity in the first place .

    Here’s someone you’d hope would be “anxious to be rid of the local dominant religions” the Pakistani girl who got shot in the face by Islamists and recovered in a British hospital to which she was airlifted:

    “Today, you can see that I am alive. I can speak, I can see you, I can see everyone,” Malala said. “It’s just because of the prayers of people. Because all people – men, women, children – all of them have prayed for me. And because of all these prayers God has given me this new life, a second life.”

    Nary a mention of the specialized medical care, medical science: the medical skill of (and perhaps a thank you to) the doctors who performed the skull reconstruction, the cochlear implant technology which restored her hearing destroyed by the attack. My sympathy is with her plight, not with the crass stupidity of her belief in a religion that led to her plight in the first place. My derision is for those in the media who paralyzed by political correctness and the multiculti meme don’t have the backbone to point this out.

    I fully understand your contempt for the barbarity and cruelty for those who are driven by the stupidity of religion but you are all too ready to jump on the outrage bandwagon instead of trying to use your powers of reason and imagination to understand the massive power of mass intoctrination as it is used throughout Islam and to a milder extent, the Christian world..
    You are only fortunate to have been born into the enlightened part of the world and not in deepest Afgahnistan (or somewhere) where your whole life experience would have been totally different. The “goodness” of Islam over the “evil” of everything else and how justified you would be in killing all the infidels outside of radical Islam would be taught to you from the earliest age possible. My advice to you would be to use your big brain to think about it more deeply.
    We are a bit off topic here but this is another debate that needs to be had.

    • In reply to #55 by sylwin1:

      In reply to #50 by godsbuster:

      In reply to #42 by sylwin1:

      In reply to #26 by godsbuster:

      In reply to #5 by mmurray:

      I fully understand your contempt for the barbarity and cruelty for those who are driven by the stupidity of religion We could do with less patronizing ‘understanding’ (so typical of our liberal cultural relativists) of contempt and more sharing and expressing of this contempt but you are all too ready to jump on the outrage bandwagon If such a wagon exists it has too few passengers and those driving it -the new Atheists- are portrayed as extremists by the politically correct media
      instead of trying to use your powers of reason and imagination to understand the massive power of mass intoctrination as it is used throughout Islam and to a milder extent, the Christian world..what powers of reason and imagination are required to see the obious?You are only fortunate to have been born into the enlightened part of the world and not in deepest Afgahnistan (or somewhere) where your whole life experience would have been totally different. The “goodness” of Islam over the “evil” of everything else and how justified you would be in killing all the infidels outside of radical Islam would be taught to you from the earliest age possible. More of the obvious. My advice to you would be to use your big brain to think about it more deeply. To arrive at the conclusion that we need less “outrage” and more “understanding”? **
      We are a bit off topic here but this is another debate that needs to be had. **Agreed

      • In reply to #56 by godsbuster:

        In reply to #55 by sylwin1:

        In reply to #50 by godsbuster:

        In reply to #42 by sylwin1:

        In reply to #26 by godsbuster:

        In reply to #5 by mmurray:

        I fully understand your contempt for the barbarity and cruelty for those who are driven by the stupidity of religion We could do with less patronizing ‘understanding’ (so typical of our liberal cultural relativists) of contempt and more sharing and expressing of this contempt but you are all too ready to jump on the outrage bandwagon If such a wagon exists it has too few passengers and those driving it -the new Atheists- are portrayed as extremists by the politically correct media
        instead of trying to use your powers of reason and imagination to understand the massive power of mass intoctrination as it is used throughout Islam and to a milder extent, the Christian world..what powers of reason and imagination are required to see the obious?You are only fortunate to have been born into the enlightened part of the world and not in deepest Afgahnistan (or somewhere) where your whole life experience would have been totally different. The “goodness” of Islam over the “evil” of everything else and how justified you would be in killing all the infidels outside of radical Islam would be taught to you from the earliest age possible. More of the obvious. My advice to you would be to use your big brain to think about it more deeply. To arrive at the conclusion that we need less “outrage” and more “understanding”?
        We are a bit off topic here but this is another debate that needs to be had. Agreed

        About 40 myears ago I was using the same vitriol as you to describe the bits of humanity I I didn’t like and I guess it made me feel better temporarily. I have to say that I don’t like them any more now but I find it more enlightening to stop short of outright hatred and become more thoughtful instead. Hatred and anger are human emotions which have evolved within us in the same way as everything else and they have their uses but they can lead to unneccassary violence. I would cite WW2 as the perfect example of this and, although there is plenty else to be said, I will just say that if reason was allowed to prevail over hatred then the worst conflict in history would never have happened. So let me remind you that you are a member of the Dawkins website which is supposed to be an “oasis of reason”. Someone said that a problem cannot be solved unless it is first of all understood and, with respect, you are nowhere near this yet.

  29. Moderators’ message

    Let’s try to keep this thread about the science of brains and not let it wander off into religion. There are plenty of other threads where religion will be totally on topic.

    Thank you.
    The mods

    • In reply to #58 by Moderator:

      Moderators’ message

      Let’s try to keep this thread about the science of brains and not let it wander off into religion. There are plenty of other threads where religion will be totally on topic.

      Thank you.
      The mods

      Sorry!

  30. This discussion has been all about “The Big Brain” and I don’t know why it was entitled thus because most human brains are all the same size give or take. But some seem to work much better than others. On the one hand we have the genius of people like Einstein and on the other the human brain seems hardly to work at all beyond basic survival needs. This may be due to genetics, accidents, culture and I don’t know how many different reasons but across the board they will turn out to be all roughly the same size.
    I say that the great intellectual achievements are mostly made by individuals whose brains are no bigger or heavier than an average but have performed way beyond that average in tems of thought quality. This has happened regardless of size.

    • In reply to #60 by sylwin1:

      This discussion has been all about “The Big Brain” and I don’t know why it was entitled thus because most human brains are all the same size give or take. But some seem to work much better than others. On the one hand we have the genius of people like Einstein and on the other the human brain seems hardly to work at all beyond basic survival needs. This may be due to genetics, accidents, culture and I don’t know how many different reasons but across the board they will turn out to be all roughly the same size.
      I say that the great intellectual achievements are mostly made by individuals whose brains are no bigger or heavier than an average but have performed way beyond that average in tems of thought quality. This has happened regardless of size.

      The term “big brain”, refers to the ratio of the brain size to body size, when compared with other animals.
      It is not about comparing the differences between individual humans.

      Brain size in primates appears to be related to the size of the groups in which they live. Those living in larger groups, have larger brains. Present city human populations, seem way in excess of the size of communities humans evolved to live in.

  31. Human brains are extremely expensive – in that the time and effort needed to teach the brain of an infant takes years of hard work by the parents (or other members of the tribe). Probably in hunter-gather situations a couple are unlikely to have more than five or six children born of which. on average, two must be survive for the species not to go extinct. A species with such a low number of offspring is particularly vulnerable to any changes in the environment that decrease survival rates. I haven’t seen any figures but we may well be the species that has the lowest number of offspring per breeding adult. In most cases I am sure having a larger number of offspring is a better survival strategy than having a larger brain.

    In addition the brain is vulnerable to blows so must have a strong skull to protect it, needs a lot of energy to keep it running – and in the African environment where we evolved there could be problems of the brain overheating.

    However some members of the whale family have big brains and they have the advantage that (1) as they live in water their brain effectively weights nothing (2) as the water is cold they need to burn energy to keep warm – so why not a bigger brain as a heat generator (3) it is hard to fall over and bang your head on a stone if you are a whale – and in any case there is a layer of blubber to give extra protection. So perhaps Douglas Adams was right when he wrote the Hitchhiker’s Guide to the Galaxy – and Dolphins are actually more intelligent than humans.

  32. Hi Sylwin1,

    When you phrase your question:

    … why did evolution take nearly all that time to discover … it must have tried every other idea available …

    … it is possible to interpret that as meaning you think of evolution as being a process seeking a goal. But in order to seek a goal you would need an intelligence behind it – and there is both no evidence that an intelligence is behind evolution, and evolution describes a process without any reference to an intelligence or goal.

    But I assume that you didn’t mean that.

    Next, there’s your phrase:

    … all that time …

    Is 3.8 billion years a long time for evolution to throw up a big brain? Evolution implies, by the very nature of the process, that a highly complex organism must be the result of a long line of generations – which must mean many, many years.

    In addition, evolution tells us that any feature of a species (a tail, lungs, eyes, wings, antibodies, a brain, etc.) must be the result of selection by the natural processes of elimination and breeding. Brains and bodies are expensive to produce, and complex brains require complex bodies – and complex brains with complex bodies must be the result of many challenging changes in the environment of our ancestors over very long periods of time.

    Perhaps 3.8 billion years is a short time to produce big brains?

    … the big brain was a clear winner in the survival stakes …

    Is it? Granted, human history and pre-historic archaeology would tend to support the idea that big brains in humans has seen us dominate Earth’s other species in the last 100,000 years – or 0.00263% of an evolutionary history of 3.8 billion years. But, as my Financial Adviser is always telling me: Past performance is no indication of future achievement.

    The Earth (our environment) is changing – climate change is building up to major changes, and our use of exhaustible raw materials continues to rise as our population rises. In addition, we face many brain-made challenges such as the proliferation of nuclear weapons. It seems to me that the Jury is still out on whether our brains are big enough – or that big brains are a good long term trait for survival.

    As far as we know there is no evidence left to us from antiquity which says that any intelligent species ever existed before the hominids. Why not?

    For the same reasons as above:

    • It takes a long time

    • There would have to have been pressure on species to develop big brains. The evidence from ourselves and our hominid ‘relatives’ suggests that living in large groups was one factor that favoured the emergence of big brains. There is also diet – evidence suggests that our ancestors started to hunt for higher calorie meat, and to cook food, which allowed them to evolve shorter guts (less expensive to build) allowing effort to be used to build bigger brains. These aspects of our ancestors lives tend to reinforce the pressures on them from their environment (loss of food from trees as the African savannah emerged, greater threats from predators on the ground, etc.) and to reinforce each other (social groups improve hunting success, hunting requires group co-ordination, bigger brains improve social interaction, etc.).

    • Rapid climate change tends to set evolution back. It seems likely that the large groups of species we call dinosaurs might have developed big brains sooner if it hadn’t been for an inconvenient asteroid.

    Peace.

  33. Reply to Stephen of Wimbledon:

    Is it? Granted, human history and pre-historic archaeology would tend to support the idea that big brains in humans has seen us dominate Earth’s other species in the last 100,000 years – or 0.00263% of an evolutionary history of 3.8 billion years. But, as my Financial Adviser is always telling me: Past performance is no indication of future achievement.

    The Earth (our environment) is changing – climate change is building up to major changes, and our use of exhaustible raw materials continues to rise as our population rises. In addition, we face many brain-made challenges such as the proliferation of nuclear weapons. It seems to me that the Jury is still out on whether our brains are big enough – or that big brains are a good long term trait for survival.

    I think more can be said on the “clear winner” remark. For one thing, having a big brain is like having any other new technology: it’s expensive, slow, and physically cumbersome. The fact that it evolved only once in one lineage, which now has only one species in it, can be taken as testament to how unsuited it is to the vast majority of survival situations. Secondly, we’re currently committing the most basic ecological blunder: increasing our population beyond the environment’s capacity to provide for it, which will inevitably result in a population crash and famine. Thirdly, our success has been measured only in a few tens of thousands of years at most. If society self-destructed before the next glaciation period, it would more or less show what an unstable strategy it is to evolve big brains like ours.

    Lastly, I don’t see any reason to brag about the “evolutionary success” of the human brain. Considering that evolutionary success involves killing, raping, torturing, starving, attacking, crippling, terrorizing, warring with, and exterminating other creatures, including fellow humans, I think some people should be a bit more cautious before touting evolutionary success with pride, as though it was also moral success.

  34. In reply to #62 by Alan4discussion:

    In reply to #60 by sylwin1:

    This discussion has been all about “The Big Brain” and I don’t know why it was entitled thus because most human brains are all the same size give or take. But some seem to work much better than others. On the one hand we have the genius of people like Einstein and on the…

    The brain is so complex and natural treatments have yet to be fully understood.
    Brain Supplements

  35. I am very interested in the big brain of humans. The answer to sylwins1′s question is that it is still evolving. As contributers have noted why stop at the billions of years it has taken to develop so far. Neu-scientists are discovering new things about it every week if not day, and are as amazed as Dawkins is in his Appetite for Wonder, as they understand the billions of connections made and which can be made, more than all the atoms in the universe according to futile efforts to calculate them. As one scienmtist recently and wryly said “The human brain is not the best instrument to examine the human brain”. Also how do we know that we are the only intelligent beings in the Universes? The jury is still very much out about that.

    • Geoff, Welcome to Dawkins. One of the few places in the world where you need to think about what you say before you say it because someone will tear it to shreds otherwise. No bad thing. Making mistakes is the most effective learning experience known to mankind as long as they are honestly pointed out to you which is only possible with a sophisticated language skill. So I suggest that the development of a voice box able to do something other than roar must have helped the “Big Brain” evolve. Maybe the capacity for high level thought is in all animals but can never become usefull intelligence without communication skills. Then whatever is thought can be tested by a peer group or other animals with equal language skills. It’s all about exchanging ideas and asking questions. It’s no accident that this very human ability is unique to the big brain. So which came first language or the big brain? I say language!

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