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REAL WORLD EVENT DISCUSSIONS
The real story of human evolution
Sunday, March 19, 2006 7:52 AM
SIGNYM
I believe in solving problems, not sharing them.
Quote: Evidence for the unique function of docosahexaenoic acid during the evolution of the modern hominid brain. Crawford MA, Bloom M, Broadhurst CL, Schmidt WF, Cunnane SC, Galli C, Gehbremeskel K, Linseisen F, Lloyd-Smith J, Parkington J. Institute of Brain Chemistry, London, United Kingdom. michael@macrawf.demon.co.uk The African savanna ecosystem of the large mammals and primates was associated with a dramatic decline in relative brain capacity associated with little docosahexaenoic acid (DHA), which is required for brain structures and growth. The biochemistry implies that the expansion of the human brain required a plentiful source of preformed DHA. The richest source of DHA is the marine food chain, while the savanna environment offers very little of it. Consequently Homo sapiens could not have evolved on the savannas. Recent fossil evidence indicates that the lacustrine and marine food chain was being extensively exploited at the time cerebral expansion took place and suggests the alternative that the transition from the archaic to modern humans took place at the land/water interface. Contemporary data on tropical lakeshore dwellers reaffirm the above view with nutritional support for the vascular system, the development of which would have been a prerequisite for cerebral expansion. Both arachidonic acid and DHA would have been freely available from such habitats providing the double stimulus of preformed acyl components for the developing blood vessels and brain. The n-3 docosapentaenoic acid precursor (n-3 DPA) was the major n-3-metabolite in the savanna mammals. Despite this abundance, neither it nor the corresponding n-6 DPA was used for the photoreceptor nor the synapse. A substantial difference between DHA and other fatty acids is required to explain this high specificity. Studies on fluidity and other mechanical features of cell membranes did not reveal a difference of such magnitude between even alpha-linolenic acid and DHA sufficient to explain the exclusive use of DHA. We suggest that the evolution of the large human brain depended on a rich source of DHA from the land/water interface. We review a number of proposals for the possible influence of DHA on physical properties of the brain that are essential for its function.
Sunday, March 19, 2006 9:03 AM
RUE
I have a vote and I'm not afraid to use it!
Quote:Iodine deficiency is, by a large margin, the most common preventable cause of mental retardation in the world. Endemic iodine deficiency remains a substantial public health problem in many parts of the world, including many areas in Europe, Asia, Africa and South America.
Sunday, March 19, 2006 9:27 AM
HAZE
Sunday, March 19, 2006 9:44 AM
Sunday, March 19, 2006 9:57 AM
Sunday, March 19, 2006 10:02 AM
CHRISISALL
Sunday, March 19, 2006 10:27 AM
Sunday, March 19, 2006 10:42 AM
Quote:I believe in evolution as told by the Flying Spaghetti Monster Chrisisall
Sunday, March 19, 2006 10:59 AM
Sunday, March 19, 2006 11:21 AM
Sunday, March 19, 2006 11:44 AM
Sunday, March 19, 2006 1:32 PM
FLETCH2
Monday, March 20, 2006 4:40 AM
Monday, March 20, 2006 4:57 AM
FINN MAC CUMHAL
Quote:Originally posted by Haze: I will admit I might be a bit biased towards the evolutionary “facts” I was thought in school, but the sea ape theory still has some way to go before if convinces me.
Monday, March 20, 2006 5:36 AM
Monday, March 20, 2006 7:23 AM
Quote:Originally posted by SignyM: But RUE- you said something that you didn't support afterwards. I get the evidence for ocean/ seaside evolution, but why an ISLAND? --------------------------------- Free as in freedom, not beer.
Monday, March 20, 2006 8:50 AM
PIRATEJENNY
Quote:But there are many holes in the story of human evolution. No fossils show the transition from quadraped to biped. The process of HOW humans transitioned from hairy, tree-dwelling vegetarians to hairless, savannah-dwelling bipedal scavengers/ gatherer/ hunter ("Man the Hunter") hasn't been satisfactorily explained in common literature.
Monday, March 20, 2006 9:04 AM
CITIZEN
Quote:Originally posted by Signym: And where is the evolutionary advantage to alcohol?
Quote:Originally posted by Haze: What I meant is our capacity to enter the mind of our prey, to think from there perspective, to stand in the middle of field with no physical evidence of where that deer went and still predict/intuit its movements. This IS a unique human trait that no other animal is capable of, to look at anther being and think from ITS point of view. That’s one heck of a hunting tool.
Monday, March 20, 2006 9:45 AM
MATTCOZ
Monday, March 20, 2006 12:21 PM
DUG
Quote:Originally posted by citizen: Quote:Originally posted by Signym: And where is the evolutionary advantage to alcohol? Alcohol is free of contaminants that cause disease (Alcohol is of course a poison but it effects bacteria and viruses more than it does us). .......
Monday, March 20, 2006 12:37 PM
Quote:Originally posted by dug: Cows and other herbivores do sometimes like to get drunk. I've seen some birds that would get so smashed on fermented grapes they couldn't fly and would fall off of the fence they landed on.
Monday, March 20, 2006 1:36 PM
Tuesday, March 21, 2006 7:14 PM
Tuesday, March 21, 2006 7:28 PM
Tuesday, March 21, 2006 7:41 PM
Quote: If I might hazard a guess? Evolutionary theory seems to need an isolated population that develops such that once that isolation is ended that population can no longer interbreed with the original species. The Aquatic Ape hypothesis would be best served if a group of homolids became seperated from the more common tree dwelling kind and forced to exploit the sea shore for survival. An island would more likely serve for genetic isolation than a shoreline.
Tuesday, March 21, 2006 7:53 PM
Tuesday, March 21, 2006 7:58 PM
Tuesday, March 21, 2006 8:06 PM
SASSALICIOUS
Quote:Originally posted by citizen: Possibly, but the fact is the main method of water purification in the Orient was boiling, in Europe it was fermentation and the amount of Alcohol in a single pint is far more than that produced by the stomach. Also remember that rice ferments pretty well and rice is a staple of the oriental diet. Quote:Originally posted by dug: Cows and other herbivores do sometimes like to get drunk. I've seen some birds that would get so smashed on fermented grapes they couldn't fly and would fall off of the fence they landed on. Many animals do. If it's not alcohol its some other substance. Some monkeys out in the rainforest (I forget what forest and what species of monkey) will pickup and bite a type of poisonous centipede that squirts it's venom at an attacker. This venom essentially gets them high. Tigers will lick a type of poisonous plant that makes them high. Drug taking is fairly common in the animal kingdom. More insane ramblings by the people who brought you beeeer milkshakes! No beast so fierce but knows some touch of pity. But I know none, and therefore am no beast.
Wednesday, March 22, 2006 4:43 AM
Quote:Originally posted by Rue: Hmmmm - you know about mirror neurons? Just what do you do for a living?
Quote:While this isn't a disagreement, I wonder if you know much about octopuses and verbal parrots. It seems to me they have an alien intelligence that we can't qualify, especially octopuses.
Quote: Pepperberg has first-hand experience in this area. Her team has studied an African Grey parrot, called Alex, in the lab for 27 years. Alex can articulate sounds for objects, shapes, colours and materials, knows the concepts of same and different, and bosses around lab assistants in order to modify his environment.
Wednesday, March 22, 2006 4:47 AM
Quote:Originally posted by SASSALICIOUS: More news from the animal kingdom: Llamas in Peru get a bit of a high by eating coca leaves, grasshoppers jump unusually high when they eat wild marijuana leaves, and elephants tend to seek out fermented ripe fruit for a bit of a buzz. Do you have any sources for the evolutionary basis of Asians tending to be deficient in alcohol dehydrogenase (enzyme that breaks down alcohol, preferentially ethanol) because what you said is interesting and I'd like to read more about it. Other groups that are also deficient: Ashkenazi Jews and possibly Native Americans and Latin Americans (assuming I'm reading this right). People of Asian descent get kicked in the ass again because they also tend to be deficient in acetaldehyde dehydrogenase. Evolution is intriguing.
Quote:In China, the preference was for warm (or boiled) water, possibly, though not necessarily, in which vegetable substances had been steeped (i.e., tea). … In other cases, as in the addition of wine to water in early modern France, the action was explicitly a purification, with greater or lesser amounts of wine added according to the estimated degree of impurity of the water
Saturday, March 25, 2006 12:05 PM
Quote:ADDIS ABABA, Ethiopia (AP) -- Scientists in northeastern Ethiopia said Saturday that they have discovered the skull of a small human ancestor that could be a missing link between the extinct Homo erectus and modern man. The hominid cranium -- found in two pieces and believed to be between 250,000 and 500,000 years old -- "comes from a very significant period and is very close to the appearance of the anatomically modern human," said Sileshi Semaw, director of the Gona Paleoanthropological Research Project in Ethiopia. Archaeologists found the early human cranium five weeks ago at Gawis in Ethiopia's northeastern Afar region, Sileshi said.
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