tag:blogger.com,1999:blog-3734925856292601239.post756436373067870128..comments2024-03-22T15:55:34.030-04:00Comments on Evo and Proud: Brain size and latitude: Why the correlation?Peter Frosthttp://www.blogger.com/profile/04303172060029254340noreply@blogger.comBlogger54125tag:blogger.com,1999:blog-3734925856292601239.post-30660503237448339532017-05-31T00:44:33.133-04:002017-05-31T00:44:33.133-04:00http://www.africaresource.com/index.php?option=com...<br />http://www.africaresource.com/index.php?option=com_content&view=article&id=554:race-and-brain-size-blacks-have-bigger-brains&Itemid=360Eddnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-13672933832087167892015-01-04T06:05:52.724-05:002015-01-04T06:05:52.724-05:00Hello.
I can provide information about the northe...Hello.<br /><br />I can provide information about the northern native American iq. more specifically the iqs of native Canadians.. please contact me at c770d099@ku.edu Cody Duncannoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-18020648071523055032014-01-12T17:05:04.267-05:002014-01-12T17:05:04.267-05:00The answer is meat consumption.
Increases in meat...The answer is meat consumption.<br /><br />Increases in meat consumption start in the Lower Paleolithic, and peak in the Upper Paleolithic. Meat consumption correlates with increased cranial capacity and increased in intelligence. Cranial capacity peaks with the Neanderthal, eating 5000 calories a day of a meat-based diet. Extinction of the large herbivores and switch to grains starts the decrease in cranial capacity. Capacity varies by latitude (Inuits and meat) and matches up with avg IQ.<br /><br />Case closed, no reason for any wacky theories...Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-83991715142038216462012-12-17T17:24:53.468-05:002012-12-17T17:24:53.468-05:00Lots of evidence to back this up.Lots of evidence to back this up.Elliott Broidyhttp://elliottbroidy.corporatenewssource.comnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-18277230722514267702011-10-10T19:16:26.394-04:002011-10-10T19:16:26.394-04:00I'll offer the world another quasi just-so sto...I'll offer the world another quasi just-so story not worst than many another, yet less heroic for nordic/caucasian/eurasian-ists to come up with: maybe if you are regularly forced to long periods of indoors limitation and inactivity, it pays off better to alocate towards being better at thinking.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-59773421092495647852011-08-04T18:59:45.157-04:002011-08-04T18:59:45.157-04:00See Eiluned Pearce and Robin Dunbar, Latitudinal v...See Eiluned Pearce and Robin Dunbar, Latitudinal variation in light levels drives human visual system size, Biology Letters, Published online before print July 27, 2011. <br /><br />In short Dark winters = bigger eyes and therefore bigger brains for visual processing.Jeanhttps://www.blogger.com/profile/16199139920477685196noreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-81186377955225573362011-08-03T04:30:07.563-04:002011-08-03T04:30:07.563-04:00Hi,
The answer lies in the food that was eaten. N...Hi,<br />The answer lies in the food that was eaten. Northern climates ate more animal based omega3 fatty acids (EPA and DHA)-derived from cold water fish. In fact much of their diet was fat based, bluber from the mammals living in the colder climates. Our brains are made of fat.<br /><br />-italian expatAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-62619982222879205612011-07-28T16:55:18.388-04:002011-07-28T16:55:18.388-04:00Quite a large number of comments...here is one mor...Quite a large number of comments...here is one more to be likely lost in the shuffle. In general, brain size does correlate with intelligence. Of course there are exceptions, some birds appear to construct tools and exhibit a kind of, "If this, then that," cognitive ability. Whales on the other hand have not developed much in the way of observable external manipulative skills. Granted body brain ratio is an indicator but not consistently so. More likely the latitudinal size differences described in this article, have to do with relative amounts of light rather than temperature. Light processing enlargement may incidentally include overall brain growth. Another factor may be a kind of neotony - a retention of juvenal characteristics brought on by hormonal cycles lengthened by lower light periods. The result being larger head body ratio and increased brain size. The issue of intelligence is a touchy one, but I suspect that the kind of cognitive skills valued by the reigning cultures would be enhanced by larger brains.labyrd@aol.comnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-90650354355205141482011-07-17T21:53:53.080-04:002011-07-17T21:53:53.080-04:00@Beyond Anon:
It is probably a combination of bot...@Beyond Anon: <br />It is probably a combination of both learning and selective pressure exerted by predation. <br /><br />All young mammals learn by observing and imitating the behavior of adult specimens. If the adult animals flee in panic because they've caught a human scent, the young will pick up on this behavior and learn to associate this scent with danger. <br /><br />Of course at the same time, there would also have been a selection for animals that were especially wary of humans. But this takes much longer than passing on learned behavior.Ishtarahttps://www.blogger.com/profile/11932407428771429360noreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-64351193606781250612011-07-15T10:51:31.080-04:002011-07-15T10:51:31.080-04:00Peter Frost says:
It doesn't take many gener...Peter Frost says:<br /><br /><i><br />It doesn't take many generations for wild animals to learn fear of humans. In any case, archaic humans were present in Eurasia for up to a million years.<br /></i><br /><br />I suspect that no actual learning is going on there, but rather, through their actions humans are selecting those who are genetically more wary of humans or strange behavior.<br /><br />How do you determine whether it is learning that is passed on from generation to generation or selection?<br /><br />This question also applies to the claims by some that the daughters of absent fathers become sexually active at an earlier age because the life-history path they select is caused by the absence of their father.<br /><br />An alternative suggestion is that the mother has passed on her genes and she is the sort of woman who selects low-commitment males when looking for a sperm donor.Beyond Anonnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-56097410039503158242011-07-15T01:27:22.755-04:002011-07-15T01:27:22.755-04:00I never bought Diamond's article that the Amer...I never bought Diamond's article that the Americas lacked in animals that were possible to domesticate. Alaska and northern Canada contain caribou, which are the same species as reindeer, which the Sami -- and possibly various other Uralic-speaking peoples of northern Russia -- domesticated for transportation, meat, milk and hides. The Swedes and Russians have had some limited success with domesticating the moose, also found in North America. I remember reading an article (which I can no longer locate) saying that the Swedes devised a moose cavalry -- it didn't work because the moose were scared of gunfire, but horses had the advantage of being domesticated prior to the invention of the gun.<br /><br />Domestication of animals involves their physical alteration. The horse was once too small and weak to support a mounted armored knight and were used mainly to pull chariots. They had to be bred for strength and size over the course of centuries. The moose and the caribou could have been transformed into completely different animals given enough time.anon666http://x@y.netnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-20367446724788013632011-07-13T16:08:09.663-04:002011-07-13T16:08:09.663-04:00Uncle Tom,
It doesn't take many generations f...Uncle Tom,<br /><br />It doesn't take many generations for wild animals to learn fear of humans. In any case, archaic humans were present in Eurasia for up to a million years.<br /><br />Even if one concedes these dubious points, Diamond's argument seems strange. Is he saying that early Eurasians did not hunt wild boar before domesticating them? (and is he saying that wild boar are docile?).<br /><br />Africa is second only to South America in its number of mammal species. Many of them, especially the larger rodents and the medium-sized ungulates, have much potential for becoming useful livestock. Some, like the buffalo, have domesticated relatives in Eurasia.Peter Frostnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-50677175176995866542011-07-13T12:19:25.042-04:002011-07-13T12:19:25.042-04:00M said...
" If larger skull size has an e...M said...<br /><i><br />" If larger skull size has an energy benefit in a cold climate and greater brain size has an energy disbenefit then wouldn't a compromise be a large, *thick* skull with a modest brain capacity be an option as long as bone was a good transmitter of heat?"<br /><br /> Do you mean insulator?<br /></i><br /><br />The original argument was that a larger head size reduced the surface area to volume, which reduces heat outflow or something.<br /><br />So the question of insulation does not apply.<br /><br />If you live in an area where there are numerous Chinese and African Americans with offspring you will no doubt have noticed something amusing: The head-size differences between Chinese children and African-American children.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-37465303586426288812011-07-12T07:04:42.144-04:002011-07-12T07:04:42.144-04:00M
"Do you mean insulator?"
Yes. It jus...M<br /><br />"Do you mean insulator?"<br /><br />Yes. It just occurred to me there might have been multiple solutions to the same problem some of which led to dead ends.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-44938972260584938172011-07-11T17:15:28.234-04:002011-07-11T17:15:28.234-04:00If you are wondering about the relationship betwee...If you are wondering about the relationship between brain size and head size then go <a href="http://books.google.co.uk/books?id=kaV2KZQjqCwC&pg=PA129&dq=iq+head+circumference&hl=en&ei=ba8YTtfCMIKEhQeI7N3MBQ&sa=X&oi=book_result&ct=result&resnum=5&ved=0CD0Q6AEwBDgU#v=onepage&q=iq%20head%20circumference&f=false" rel="nofollow">HERE</a>. It shows that the low correlation of head size and brain size makes it rather far fetched to imply that brain tissue would be isometrically scaled up with head size or that brain would be metabolically cheaper than skull thickness.<br /><br />The link also discusses an amazing autopsy study of brain size and intelligence. <a href="http://brain.oxfordjournals.org/content/129/2/386.short" rel="nofollow"> Witelson (2006)</a>Todnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-90843631523272356262011-07-11T16:28:40.273-04:002011-07-11T16:28:40.273-04:00animals in Africa evolved with higher primates (an...<i>animals in Africa evolved with higher primates (and eventually "Man") they had a natural hostility to humans, where as Eurasian primates did not tend to</i><br /><br />Eurasian *animals*,<br /><br />The idea that Chumans (or the rather rare earlier humans) would have a great selective pressure on animals in Africa above and beyond normal pressures from predation seems strange.<br /><br />Plus, Eurasian animals were in the presence of an (admittedly probably lower density, or least, absolute number) of Homo Erectus (and successor) species...<br /><br />It seems really hard to judge whether wolves were easier to domesticate than the African Wild Dog, or whether wild horses were originally easier to domesticate than Zebras. The only one that really seems plausible is the African Buffalo.<br /><br />I'm not too sure domestication is necessarily evidence of intelligence, but I'm quite skeptical that it is explained by "African animals are hard to domesticate".Mnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-21999121680751914352011-07-11T16:28:31.574-04:002011-07-11T16:28:31.574-04:00African animals like lions and elephants are amena...African animals like lions and elephants are amenable enough to be used in circuses. Europe's large animals were domesticated out of existence (ie are still around in domesticated form).<br /><br />Neanderthals were hunting Europe's wild animals for how long ? <br /><br />Neanderthals could not throw spears and were slow and clumsy runners. If they speared prey by running at them the final rush would immediately startle the prey into flight, Neanderthals couldn't have covered the last 10-15 meters fast enough to catch a animal stationary (if he could catch it at all, which I doubt). It would certainly be moving away from the hunter and so the spear strike would have very little actual velocity.<br /><br />Neanderthals were pretty clumsy and what they probably did was lurk around woodland game trails and wait for the prey animals to walk into a prepared ambush then pop up to surround them and hence the animal would be speared as it tried to break through the cordon.<br /><br />So, European animals had surely evolved to fear 'humans' by the time modern humans arrived in Europe <br /><br />CroMags were were able to prey on European animals much more effectively because they had invented new projectile technology such as spear throwers.Todnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-48412966607456518892011-07-11T15:25:11.525-04:002011-07-11T15:25:11.525-04:00If larger skull size has an energy benefit in a co...<i>If larger skull size has an energy benefit in a cold climate and greater brain size has an energy disbenefit then wouldn't a compromise be a large, *thick* skull with a modest brain capacity be an option as long as bone was a good transmitter of heat?</i><br /><br />Do you mean insulator?<br /><br />Another alternative would be a larger brain with lower neuron density and a higher glial density and volue of fluid, but a similar number of neurons overall. That would lower some of the energetic cost of running a larger brain (and possibly some of the developmental cost) while providing the Allen's Rule advantage a larger brain has.<br /><br />This is difficult to test - it's easy to get cranial capacities, but we can't really get access to brain autopsies from different groups -, though in my heart of hearts I doubt human populations which are cold adapted will have lower neuron density with their greater cranial capacity.<br /><br />Notwithstanding that yes, it would seem to be cheaper to build a skull thick rather than build a larger number of glia and volume of extracellular fluid (although I'm not sure - maybe the cost of depositing bone works out heavier).Mnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-52300954039942784122011-07-11T14:18:38.532-04:002011-07-11T14:18:38.532-04:00Here is an exact quote from Diamond, but his sourc...Here is an exact quote from Diamond, but his source is still unknown to me:<br /><br />"Ironically, the long human presence in Africa is probably the reason the continent's species of big animals survive today. African animals co-evolved with humans for millions of years, as human hunting prowess gradually progressed from the rudimentary skills of our early ancestors. That gave the animals time to learn a healthy fear of man, and with it a healthy avoidance of human hunters. In contrast, North and South America and Australia were settled by humans only within the last tens of thousands of years. "<br /><br />http://ngm.nationalgeographic.com/ngm/0509/resources_geo2.htmlUncleTomRuckusInGoodWhiteWorldhttps://www.blogger.com/profile/07508650487951730570noreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-88748316182619267422011-07-11T13:23:59.690-04:002011-07-11T13:23:59.690-04:00Peter:
To Insightful's post, I believe Diamon...Peter:<br /><br />To Insightful's post, I believe Diamond said that because animals in Africa evolved with higher primates (and eventually "Man") they had a natural hostility to humans, where as Eurasian primates did not tend to.<br /><br />I'm not sure of Diamond's reference to this, as I no longer have his book. :-( <br /><br />I will look for the info today.UncleTomRuckusInGoodWhiteWorldhttps://www.blogger.com/profile/07508650487951730570noreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-54339809173360840992011-07-11T12:06:31.305-04:002011-07-11T12:06:31.305-04:00All,
There are so many comments that I cannot rep...All,<br /><br />There are so many comments that I cannot reply to all of them. Please don't feel offended if I don't reply directly to your comment.<br /><br />Greg,<br /><br />Trinkaus was comparing early modern humans before and during the last ice age. There was no increase in brain size. I suspect the decrease over the last 10,000 was due to the shift from hunting and gathering to agriculture. Specifically, hunters have to store huge amounts of spatio-temporal information, i.e., current and projected locations of game animals, landmarks, layout of hunting routes, etc.<br /><br />Uncle Tom,<br /><br />My point wasn't that life was better in the tropical zone than in the temperate and arctic zones. Rather, it was that environmental hardship tends to follow a predictable yearly cycle outside the tropics. In the tropics, environmental hardship tends to be less predictable and more random.<br /><br />There is a lot of "presentism" in the comments by you and others. Today, life is hard in sub-Saharan Africa because the population has been artificially increased well beyond the land's carrying capacity. This is a recent phenomenon. <br /><br />Similarly, famine was a routine occurrence throughout all of Europe as late as the 1700s. Most farming families suffered hunger in early spring -- when the harvest from last year was running out and when this year's harvest was not yet ready.<br /><br />Insightful,<br /><br />Yes, I'm familiar with Jared Diamond's book. A few questions:<br /><br />1. How do you explain the rise of advanced civilizations in Mesoamerica and Peru? Neither region had the benefit of east-west exchange of cultural innovations.<br /><br />2. Please justify your statement that the wild precursors of Eurasian livestock were more docile than similar wild animals in Africa. I have seen this statement made repeatedly, but I have yet to see any justification. And why is it that Africa's one domesticated food animal (guinea fowl) appears to have been domesticated by women? Could it be that African men were less involved in food provisioning for their families?Peter Frostnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-64843232912209506992011-07-11T12:02:50.398-04:002011-07-11T12:02:50.398-04:00The Eskiomos/ Inuit do have the highest IQ among A...The Eskiomos/ Inuit do have the highest IQ among Amerindians, according to this review:<br /><br />http://www.gnxp.com/blog/2006/02/<br />world-of-difference-richard-lynn-maps.phpBruce Charltonhttps://www.blogger.com/profile/09615189090601688535noreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-39523450256829618532011-07-11T09:05:54.446-04:002011-07-11T09:05:54.446-04:00Insightful
"I've been to Europe and alth...Insightful<br /><br />"I've been to Europe and although it is no walk in the park I think it has a pleasant climate overall, perhaps one of the most pleasant climates in the world."<br /><br />Aryan invasions<br />Dorian invasions<br />Celtic invasions<br />Germannic invasions<br />etc<br /><br />It's not that the people who lived in the middle of what is now France or Britain changed dramatically. It's that people similar to them who moved or were pushed further north into the much harsher band closer to the ice changed dramatically and then *came back* in multiple waves over two to four thousand years and mixed with the originals<br /><br />(just by coincidence usually bringing with them militarily useful technological advances like better metal-working or the wheel).Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-15277584137913282352011-07-11T08:39:16.864-04:002011-07-11T08:39:16.864-04:00"huge brain of Cro-Magnon man was a spandrel...."huge brain of Cro-Magnon man was a spandrel. Surely bigger brains are too metabolically expensive for that."<br /><br />If larger skull size has an energy benefit in a cold climate and greater brain size has an energy disbenefit then wouldn't a compromise be a large, *thick* skull with a modest brain capacity be an option as long as bone was a good transmitter of heat?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-65004540489860457552011-07-11T08:26:52.007-04:002011-07-11T08:26:52.007-04:00"It is difficult to believe that Inuit are no..."It is difficult to believe that Inuit are not any more intelligent than equatorial Amerindians given the challenges posed by their environment."<br /><br />The Inuit or Arab desert-dwellers or a dozen other groups living in hostile environments have the *same* challenges all year round.<br /><br />I think the distinction, if there is one, is a *changing* hostile environment over a yearly cycle.<br /><br />The peak line for this might run something like Finland to Japan.Anonymousnoreply@blogger.com