//////////////TO BE NOBODY BUT YOURSELF
/////////////Anorexia linked to 'autistic' thinking
22 April 2009 by Linda Geddes
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A GROWING appreciation of the links between anorexia and autism spectrum disorders has uncovered new opportunities for treating the eating disorder.
Mental health professionals are now attempting to train the brains of people with anorexia to be more flexible and to see the big picture as well as fine details. In doing so, they hope patients will be less inclined to obsess about body weight and calories and be better equipped to overcome their eating disorder in the long term, as well as gaining weight more immediately.
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/////////////////////Sibling worlds may be wettest and lightest known
15:49 21 April 2009 by Stephen Battersby, Hatfield
Magazine issue 2705. Subscribe and get 4 free issues.
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Video: Water world discovered
A planet orbiting a red dwarf star 20 light years away could be the first known water world, entirely covered by a deep ocean.
The planet, named Gliese 581d, is not a new discovery, but astronomers have now revised its orbit inwards, putting it within the "habitable zone" where liquid water could exist on the surface. "It is the only low-mass planet known inside the habitable zone", says Michel Mayor of Geneva Observatory.
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//////////////////HOMININ AUSTRALOPETHICUS-OUR ANCESTORS=Dunbar and his Oxford colleague Caroline Bettridge are now applying what they have learned about chimps to our early ancestors the australopithecines. This group of hominins, consisting of around half a dozen species, lived in Africa between 3.5 and 1.8 million years ago, when the climate was generally warmer than now. Dunbar and Bettridge's study is based on 68 sites at which fossilised remains have been found. Information about climate at these sites - and hence likely group size - can be gleaned from geological formations and the fossilised plants and animals they contain. Another indicator of group size comes from measuring the cranial volume of the fossils: larger brains seem to correlate with bigger group size, reflecting the cognitive capacity required to maintain complex social networks. Based on fossil remains, australopithecines probably had the brainpower to live in groups of up to 70 individuals.
We are now applying what we have learned about chimps to our early ancestors
With this information, the researchers have started to make educated guesses about australopithecine behaviour. It seems unlikely that they roamed and foraged in the same way as modern chimps. "If their ecology had been like that of chimpanzees, they would have been hard pressed to survive in most of the places that we know from the fossil record they did in fact occupy," Dunbar says. In their hot open homelands, they would have had to spend too much time on the move to feed themselves. "We can then ask which parameter values need to be tweaked to 'get them to live' in the habitats we know they lived in, and not in those we know they didn't."
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........The fossil record indicates that around 6 million years ago, just after the split with chimp ancestors, the size difference between male and female human ancestors was substantial: greater than that seen in modern chimpanzees, though less than in gorillas. Size dimorphism then gradually decreased as females became larger while males stayed around the same size, until modern size differences appeared with Homo erectus around 2 million years ago. This, Plavcan says, suggests something interesting was going on. In most primate groups, when females get bigger, males tend to follow suit. Why didn't our ancestors follow this pattern?
Plavcan points out that size dimorphism can only persist if the biggest males can monopolise females and so pass on their genes at the expense of smaller males. That cycle can be broken if females change their behaviour in a way that makes it more difficult for a single male to monopolise them. If that happens, more males become able to pass on their genes, reducing competition for females and removing some of the pressure to be big, leading to a reduction in size dimorphism. The decreasing size differences of our ancestors "tells us that the way females behave is changing", Plavcan says.
..............Big brains have benefits, but they come at a price. They are metabolically expensive to run, and building them demands not only a lot of energy but also significant nurturing. These costs hit where it hurts: in the currency of reproductive success. Another comparative analysis drives home the point. When Karin Isler and Carel van Schaik from the University of Zurich, Switzerland, surveyed 1247 animal species, including some primates, they found that in general the bigger the brain relative to body size, the less fecund the species.
This leaves humans in an odd position. Human babies are helpless when born, take a long time to grow and reach independence, and demand massive parental investment. Yet humans are highly fecund: in hunter-gatherer societies without modern birth control, the interval between births is around two to three years, compared with five years in chimps and eight in orang-utans.
Babies are helpless when born and demand massive parental investment, yet humans are highly fecund
There are other exceptions to the rule that big brains equal low fecundity. Large-brained birds such as owls and woodpeckers are often blind when they hatch and always require lots of nurturing, yet produce chicks as frequently as their smaller-brained relatives (Biology Letters, vol 5, p 125). The same combination of large brains and high fecundity is also found in wolves, foxes, coyotes and jackals. The common factor is allomaternal care, where mothers raising young can call on help from others, including fathers, older offspring or even unrelated individuals.
.............So when did the hominin brain become so large that shared care was essential if high fecundity was to be maintained? Isler and van Schaik calculate that for australopithecines 3 million years ago the inter-birth interval was around 6.5 years, decreasing to around 4.5 years by 2 million years ago as H. erectus was emerging, and to something comparable to today's hunter-gatherer societies from about 1 million years ago. "We calculated that allomaternal care is required once adult brain size reaches about 1000 cubic centimetres, or about Homo erectus size," says Isler. Above this size, ape-like caring systems cannot sustain reproductive output at a level to keep the species viable, and it would be likely to die out, she argues.
So can we now be confident that allomaternal care emerged in our ancestors somewhere between 1.5 and 2 million years ago? Not quite. "Our calculations of inter-birth intervals are rather rough," Isler admits. "And the estimate of a 'grey ceiling' of 1000 cubic centimetres, beyond which a traditional ape-like childcare style would not be feasible, is based on some assumptions that are not easy to test, such as infant mortality rates in extinct species." Plavcan is even more cautious, given that the deductions made from studying living primates have yet to be corroborated with fossil evidence. "The fossil record is thin on this issue," he says. While there could well be a link between brain size, child care and dimorphism, he recognises that we cannot be sure about the chronology without stronger evidence of the cranial capacity of H. erectus.
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////////////////DTH BY CA OR AXDNT EQVLNT COPING MECHANISM
///////////////////////BUYING 2ND HAND FURNITURE IS GREEN
////////////////////CHLDHOOD DDDY LATE SYNDROME-ADLT WF LATE SYNDROME
////////////////XIV.6. TATRA SATTWAM NIRMALATWAAT PRAKAASHAKAM ANAAMAYAM;
SUKHASANGENA BADHNAATI JNAANASANGENA CHAANAGHA.
(Krishna speaking to Arjuna)
Of these, Sattwa, which from its stainlessness is luminous and
healthy, binds by attachment to knowledge and to happiness, O
sinless one!
XIV.7. RAJO RAAGAATMAKAM VIDDHI TRISHNAASANGASAMUDBHAVAM;
TANNIBADHNAATI KAUNTEYA KARMASANGENA DEHINAM.
Know thou Rajas to be of the nature of passion, the source of
thirst (for sensual enjoyment) and attachment; it binds fast, O
Arjuna, the embodied one by attachment to action!
XIV.8. TAMASTWAJNAANAJAM VIDDHI MOHANAM SARVADEHINAAM;
PRAMAADAALASYANIDRAABHIS TANNIBADHNAATI BHAARATA.
But know thou Tamas to be born of ignorance, deluding all embodied
beings; it binds fast, O Arjuna, by heedlessness, sleep and
indolence!
//////////////////A WORLD WITHOUT RELIGN DOES NOT HAVE A PRAYER
//////////////////////QUOTE MINING-DAWKINS
///////////////////UNBUDGABLE VERACITY OF 2ND LOTD
///////////////////EDDINGTON CONCESSION
/////////////////////POETIC MYSTERY OF UNKNOWN-EINSTEINS GD
////////////////////////WHY DID U TAKE SUCH PAINS TO HIDE YOURSELF?
////////////////////DIRECTED PANSPERMIA IS BEST SHOT FOR ID
///////////////////PRINCIPLE OF MEDIOCRITY
///////////FERMI- WHERE IS EVERYBODY?
///////////////ORIGIN OF TECHNOLOGICAL LIFE
/////////////////////TECHNOLOGICAL LIFE BLOWS ITSELF UP QUICKLY
//////////////////EVOLN AS CRANE NOT A SKY HOOK
///////////////////ANTHROPIC PRINCIPLE-PLANETARY AND COSMIC VIEWPOINTS
/////////////////
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