A Stanford geneticist says humans have so many genetic mutations that we’re less intelligent than our ancestors, and it’s getting worse. Eugenicists 100 years ago had similar hypotheses.
There’s this great recurring “Saturday Night Live” skit from several years back where Phil Hartman plays an unfrozen caveman who goes to law school. He pontificates on the American judicial system while marveling at modern technology like “the tiny people in the magic box” (a TV). It fits a common stereotype: Human ancestors were, well, cavemen, and not as smart as we are today. A provocative new hypothesis from a Stanford geneticist tries to turn this stereotype upside down.
Human intelligence may have actually peaked before our ancient predecessors ever left Africa, Gerald Crabtree writes in two new journal articles. Genetic mutations during the past several millennia are causing a decline in overall human intellectual and emotional fitness, he says. Evolutionary pressure no longer favors intellect, so the problem is getting exponentially worse. He is careful to say that this is taking quite a long time, so it’s not like your grandparents are paragons of brilliance while your children will be cavemen rivaling Hartman’s SNL character. But he does posit that an ancient Athenian, plucked from 1000 BC, would be “among the brightest and most intellectually alive of our colleagues and companions.”
His central thesis is that each generation produces deleterious mutations, so down the line of human history, our intelligence is ever more impaired compared to that of our predecessors.
Not surprisingly, the hypothesis, published in the prominent journal Trends in Genetics, has several geneticists scratching their heads.
“It takes thousands and thousands of genes to build a human brain, and mutations in any one of those can impair that process, that’s absolutely true. And it’s also true that with each new generation, new mutations arise ... but Crabtree ignores the other side of the equation, which is selection,” said Kevin Mitchell, associate professor at the Smurfit Institute of Genetics at Trinity College Dublin, who operates the blog Wiring the Brain. “Natural selection is incredibly powerful, and it definitely has the ability to weed out new mutations that significantly impair intellectual ability. There are various aspects in these papers that I think are really just thinking about things in a wrong way.”
Crabtree said he wanted to examine the cumulative effect of generation-to-generation mutation on intelligence, which is thought to be controlled by many genes. Using indices that measure X-chromosome-related mental retardation, he comes up with between 2,000 and 5,000 genes related to human intellectual ability. Using another index measuring average mutations that arise in each generation of children, he calculates that within 3,000 years, “we have all sustained two or more mutations harmful to our intellectual or emotional stability.”
“There is a general feeling that evolution constantly improves us, but it only does that if there is selection applied,” Crabtree said in an interview. “In this case, it is questionable about how much selection is occurring now compared to the process of optimizing those genes, which occurred in the jungles of Africa 500,000 years ago.”
There’s already evidence for this in other areas, he argues: Take our sense of smell. Humans have far fewer olfactory receptors than other animals, he said--we’re guided by our intellect now, not by smell. We can think about where a piece of food came from, how it was processed, which plant it’s from, who has been around it, and so on. A dog, on the other hand, simply sniffs something and either eats it or doesn’t.
“Once you place pressure on intellectual abilities, and take it off of olfactory abilities, the olfactory genes deteriorate,” Crabtree said.
Similarly, he believes evolution now selects for other traits--namely, the most healthy and the most immune, not the most intelligent. Human movement into communities and cities increased the spread of infectious diseases, and those with the strongest physical constitutions survived to pass on their genes, he argues. He said he wanted to publish this hypotheses because geneticists can test for this, in an expensive process that requires saving some genetic information that typically gets discarded.
Rapid Geomagnetic Reversal Possibility: Confirmed 2014 10 21
From the video: "The scientists who conducted the study are still unsure why the magnetic field is weakening, but one likely reason is the Earth’s magnetic poles are getting ready to flip, said Rune Floberghagen, the ESA’s Swarm mission manager. In fact, the data suggest magnetic north is moving toward Siberia."
Tune into Red Ice Radio:
Ben Davidson - Suspicious0bservers: Space Weather ...
Georgia Guide Stone 2014 cube stone removal 2014 10 21
From: Youtube: Was it all just a gag? it seems the cube stone just happens to be made out of the same Elberton granite that the rest of this morbid monument is made from.
Secret Project Created Weaponized Ebola In South Africa In The 1980s 2014 10 21 “No records are available to confirm that the biological agents were destroyed.”
Operating out of South Africa during the Apartheid era in the early 1980’s, Dr. Wouter Basson launched a secret bioweapons project called Project Coast. The goal of the project was to develop biological and chemical agents that would either kill or sterilize the black population and assassinate political enemies. ...
Controlling the American Mind: The Viral Liturgical Psychodrama 2014 10 20
In order to successfully navigate the raging sea of media shit storm, one must be ever-mindful of the overall designs of mass media without getting lost in endless details and rabbit trails that will be forgotten in a month. Remember Bowe Bergdahl? Remember how media was furiously researching his back story to make details match-up, all of which ended up ...