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Human evolution: Small gut, big brain theory of brain size comes under fire

From “Monkeys did not gain big brains by shrinking guts” (New Scientist, August 11, 2011 ) we learn that some doubt has been cast on the theory known as the (“expensive tissue hypothesis”), that eating – and cooking – meat helped us develop big brains. That’s because digestion became a less cumbersome process. Howver,

Kari Allen and Richard Kay of Duke University in Durham, North Carolina, turned to New World monkeys to explore the hypothesis. Previous studies offer a wealth of data on the monkeys’ diets and show that their brain size varies greatly from species to species. But when the pair controlled for similarities between related species, they found no correlation between large brains and small guts (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2011.1311).

Oxford critic Robin Dunbar responded, “It is one thing to say that the hypothesis doesn’t apply to New World monkeys, and another to extrapolate that to humans.”

But people do that all the time, Robin. It’s the sport called “human evolution.” If lemurs eat their young under stress, we have an instant theory in the making about why women may yell at their children more often if they live in a war zone. And that theory is just fine with everyone. But let something more specific, like the “expensive tissue hypothesis” be disconfirmed, and we hear … heck, we just heard it.

See also: Flores man really was microcephalic, researchers say

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2 Responses to Human evolution: Small gut, big brain theory of brain size comes under fire

  1. The expensive tissue hypothesis is stupid anyway. After all, evolution has overcome it on numberous occasions (remember, we’re not still bacteria, now are we?). Why couldn’t it overcome it in the present case? Oh, that’s right, there is no reason. Sometimes it works; sometimes it doesn’t. No rhyme or reason, no defined mechanism, no predictive capability. Only ad hoc just so stories on and on . . .

  2. As to the ‘expensive tissue hypothesis’, and Eric’s observation that anything larger than a bacteria could be considered ‘expensive tissue’ in a Darwinian sense, there is far more truth to this observation than meets the eye as this following exchange illustrated;

    Michael Behe defends the one ‘overlooked’ protein/protein binding site generated by the HIV virus, that Abbie Smith and Ian Musgrave had found, by pointing out it is well within the 2 binding site limit he set in “The Edge Of Evolution” on this following site:

    Response to Ian Musgrave’s “Open Letter to Dr. Michael Behe,” Part 4
    “Yes, one overlooked protein-protein interaction developed, leading to a leaky cell membrane — not something to crow about after 10^20 replications and a greatly enhanced mutation rate.”
    http://behe.uncommondescent.com/page/4/

    An information-gaining mutation in HIV? NO!
    http://creation.com/an-informa.....ion-in-hiv

    In fact, I followed this debate very closely and it turns out the trivial gain of just one protein-protein binding site being generated for the non-living HIV virus, that the evolutionists were ‘crowing’ about, came at a staggering loss of complexity for the living host it invaded (People) with just that one trivial gain of a ‘leaky cell membrane’ in binding site complexity. Thus the ‘evolution’ of the virus clearly stayed within the principle of Genetic Entropy since far more functional complexity was lost by the living human cells it invaded than was ever gained by the non-living HIV virus. A non-living virus which depends on those human cells to replicate in the first place. Moreover, while learning HIV is a ‘mutational powerhouse’ which greatly outclasses the ‘mutational firepower’ of the entire spectrum of higher life-forms combined for millions of years, and about the devastating effect HIV has on humans with just that one trivial binding site being generated, I realized if evolution were actually the truth about how life came to be on Earth then the only ‘life’ that would be around would be extremely small organisms with the highest replication rate, and with the most mutational firepower, since only they would be the fittest to survive in the dog eat dog world where blind pitiless evolution rules and only the ‘fittest’ are allowed to survive.

    ===================

    As well, the virus is far more complex than many people have ever imagined, as this following video clearly points out:

    Virus – Assembly Of A Nano-Machine – video
    http://www.metacafe.com/watch/4023122

    Though most people think of viruses as being very harmful to humans, the fact is that the Bacteriophage (Bacteria Eater) virus, in the preceding video, is actually a very beneficial virus to man for it is one of the main mechanisms found in nature by which bacteria populations are kept in check so as to keep them from ‘overpopulating’ the world. If bacteria did not have such in-built mechanisms keeping them in check, the effect on the environment of the earth would soon throw the entire ecology of the planet into chaos, thus making the earth inhospitable for higher life forms which depend on bacteria to stay in perfect ‘life-enabling’ balance.

    Microbial life can easily live without us; we, however, cannot survive without the global catalysis and environmental transformations it provides. – Paul G. Falkowski – Professor Geological Sciences – Rutgers
    http://www.bioinf.uni-leipzig......g_2008.pdf

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