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Have human brains shrunk, and does it matter?

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File:A small cup of coffee.JPG From Phys.org:

A new replica of an early modern human brain has provided further evidence for the theory that the human brain has been shrinking. The skull belonged to an elderly Cro Magnon man, whose skeleton is called Cro Magnon 1. The entire skeleton was discovered in 1868 in the Cro Magnon cave in Dordogne, France, and has since become one of the most famous Upper Palaeolithic skeletons. Using new technology, researchers have produced a replica of the 28,000-year-old brain and found that it is about 15-20% larger than our brains.

Actually, it doesn’t matter much because intellectual capacity is mostly governed by the wiring:

The finding doesn’t suggest that humans today are less intelligent than earlier humans. Although previous studies have found a very small relationship between brain size and intelligence, many other factors affect brain intelligence. More.

For sure. Otherwise, great whales would rule the world.

See also: The Science Fictions series at your fingertips (human evolution)

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aarceng you ask: "Does that mean the human race is 5000/.86~=5814 years old?" No. It just shows that information was lost when Europeans diverged from Africans.,,,, I believe the mathematical discrepancy has to do with the expansion in population sizes, as well as other mitigating factors in population genetics. bornagain77
@bornagain77 quotes "Eighty-six percent of the genetic variation or mutations that are expected to be harmful arose in European-Americans in the last five thousand years, said the researchers." Does that mean the human race is 5000/.86~=5814 years old? aarceng
I like the following reaction of a reporter when he found out about shrinking brains in humans:
If Modern Humans Are So Smart, Why Are Our Brains Shrinking? - January 20, 2011 Excerpt: John Hawks is in the middle of explaining his research on human evolution when he drops a bombshell. Running down a list of changes that have occurred in our skeleton and skull since the Stone Age, the University of Wisconsin anthropologist nonchalantly adds, “And it’s also clear the brain has been shrinking.” “Shrinking?” I ask. “I thought it was getting larger.” The whole ascent-of-man thing.,,, He rattles off some dismaying numbers: Over the past 20,000 years, the average volume of the human male brain has decreased from 1,500 cubic centimeters to 1,350 cc, losing a chunk the size of a tennis ball. The female brain has shrunk by about the same proportion. “I’d call that major downsizing in an evolutionary eyeblink,” he says. “This happened in China, Europe, Africa—everywhere we look.” http://discovermagazine.com/2010/sep/25-modern-humans-smart-why-brain-shrinking
Moreover, it is not only brain size, but the entire human body is shrinking:
Scientists Discover Proof That Humanity Is Getting Dumber, Smaller And Weaker By Michael Snyder, on April 29th, 2014 Excerpt: An earlier study by Cambridge University found that mankind is shrinking in size significantly. Experts say humans are past their peak and that modern-day people are 10 percent smaller and shorter than their hunter-gatherer ancestors. And if that’s not depressing enough, our brains are also smaller. The findings reverse perceived wisdom that humans have grown taller and larger, a belief which has grown from data on more recent physical development. The decline, said scientists, has happened over the past 10,000 years. http://thetruthwins.com/archives/scientists-discover-proof-that-humanity-is-getting-dumber-smaller-and-weaker
This 'shrinking' finding fits the genetic study that found the genome of man has been deteriorating over the past 5 to 10 thousand years:
Human Genetic Variation Recent, Varies Among Populations - (Nov. 28, 2012) Excerpt: Nearly three-quarters of mutations in genes that code for proteins -- the workhorses of the cell -- occurred within the past 5,000 to 10,000 years,,, "One of the most interesting points is that Europeans have more new deleterious (potentially disease-causing) mutations than Africans,",,, "Having so many of these new variants can be partially explained by the population explosion in the European population. However, variation that occur in genes that are involved in Mendelian traits and in those that affect genes essential to the proper functioning of the cell tend to be much older." (A Mendelian trait is controlled by a single gene. Mutations in that gene can have devastating effects.) The amount variation or mutation identified in protein-coding genes (the exome) in this study is very different from what would have been seen 5,000 years ago,,, The report shows that "recent" events have a potent effect on the human genome. Eighty-six percent of the genetic variation or mutations that are expected to be harmful arose in European-Americans in the last five thousand years, said the researchers. The researchers used established bioinformatics techniques to calculate the age of more than a million changes in single base pairs (the A-T, C-G of the genetic code) that are part of the exome or protein-coding portion of the genomes (human genetic blueprint) of 6,515 people of both European-American and African-American decent.,,, http://www.sciencedaily.com/releases/2012/11/121128132259.htm
This is not an anomaly only for humans, but 'loss' is found to be a general trend in the fossil record:
Dollo's law and the death and resurrection of genes: Excerpt: "As the history of animal life was traced in the fossil record during the 19th century, it was observed that once an anatomical feature was lost in the course of evolution it never staged a return. This observation became canonized as Dollo's law, after its propounder, and is taken as a general statement that evolution is irreversible." http://www.pnas.org/content/91/25/12283.full.pdf+html New Species, Darwin Wrong Again - June 28, 2013 Excerpt: By examining the fossil records of 19 Cenozoic terrestrial mammal clades, Quental and Marshall discovered extinction rates exceeding the formation rates of new species. Fossil record evidence demonstrates that the rate of extinction far exceeds the formation of new species. ,,, The investigators found no evidence for the emergence of any new species. These fossil record findings undermine Darwin’s theory that changing environments are a driving force of evolution: “under changing conditions of life, there is no logical impossibility in the acquirement of any conceivable degree of perfection through natural selection.” Rather than acquiring “any degree of perfection” in the wake of environmental changes, the effect increased the rate of extinction, not speciation. ,,,When species are challenged by changing environments, rather than adapting, the pendulum swings in favor of destruction?extinction rather than “the acquirement of any conceivable degree of perfection.” Darwin’s natural selection pendulum favors extinction, not the formation of new species. http://www.darwinthenandnow.com/2013/06/new-species-darwin-wrong-again/ A. L. Hughes's New Non-Darwinian Mechanism of Adaption Was Discovered and Published in Detail by an ID Geneticist 25 Years Ago - Wolf-Ekkehard Lönnig - December 2011 Excerpt: The original species had a greater genetic potential to adapt to all possible environments. In the course of time this broad capacity for adaptation has been steadily reduced in the respective habitats by the accumulation of slightly deleterious alleles (as well as total losses of genetic functions redundant for a habitat), with the exception, of course, of that part which was necessary for coping with a species' particular environment....By mutative reduction of the genetic potential, modifications became "heritable". -- As strange as it may at first sound, however, this has nothing to do with the inheritance of acquired characteristics. For the characteristics were not acquired evolutionarily, but existed from the very beginning due to the greater adaptability. In many species only the genetic functions necessary for coping with the corresponding environment have been preserved from this adaptability potential. The "remainder" has been lost by mutations (accumulation of slightly disadvantageous alleles) -- in the formation of secondary species. http://www.evolutionnews.org/2011/12/a_l_hughess_new053881.html Evolutionists Are Losing Ground Badly: Both Pattern and Process Contradict the Aging Theory – Cornelius Hunter - July 2012 Excerpt: Contradictory patterns in biology include the abrupt appearance of so many forms and the diversity explosions followed by a winnowing of diversity in the fossil record. It looks more like the inverse of an evolutionary tree with bursts of new species which then die off over time. http://darwins-god.blogspot.com/2012/07/evolutionists-are-losing-ground-badly.html "Also that mammalian life was richer in kinds, of larger sizes, and had a more abundant expression in the Pliocene than in later times." Von Engeln & Caster Geology, p.19 "Alexander Kaiser, Ph.D., of Midwestern University’s Department of Physiology,,, was the lead author in a recent study to help determine why insects, once dramatically larger than they are today, have seen such a remarkable reduction in size over the course of history." Science Daily, 8/8/07 Don Patton - Entropy, Information, and The 'Deteriorating' Fossil Record - video (Notes on giant fossils in description and comment section) http://www.vimeo.com/17050184 Genetic Entropy - Dr. John Sanford - Evolution vs. Reality - video https://vimeo.com/35088933

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