, , ,

Lion of the Blogosphere has an interesting article up about the genomics of height and intelligence. He writes:

Height, like intelligence, is a complicated polygenic trait involving hundreds, probably thousands, of genetic variants.

It’s interesting how the discussion has changed in recent years from genes to genetic variants. I even go further and now use the term “genomic variants”.

Lion continues:

But unlike intelligence, it’s not politically incorrect to study the genetics of height, or to assume that if a particular ethnicity is very tall or very short, then it’s because of genetics.

Because if you say a person or ethnicity is genetically smarter, we equate this with genetic superiority, a concept many people find offensive.

But in a way calling a group genetically taller also implies genetic superiority. Height is right up there with intelligence as one of the most universally valued traits. Not only do most women not want to date a guy under 5’9″ but sperm banks don’t even accept their sperm because they’re considered genetic trash.

The culture is awash in height supremacist metaphors: We “look up” to those we admire and “look down” on those we disdain. Taller men make more money, achieve more education, and are more likely to lead corporations and entire nations. “Standing tall” is a metaphor for having dignity.

But of course intelligence is what makes us human. Height is not.

Lion continues:

Thus, it’s interesting that scientists have discovered a single genetic variant that contributes to Peruvians being short.

The same techniques could be used to investigate intelligence. It would be beneficial to study the smartest ethnicity (Ashkenazi Jews) and extremely low-intelligence ethnicities like Aboriginal Australians and southern African Bushmen. I’m sure if we did that, we could discover additional genetic variants related to intelligence.

Scientists are working hard on exactly this, but because it’s politically incorrect to label any extant human populations “low intelligence”, they are instead focusing on extinct ones like Neanderthals. From a New York Times article about Svante Paabo, who played a major role in sequencing the Neanderthal genome:

 Reconstructing a Neanderthal genome was a tour de force, we can all agree, but why does it matter?

Paabo spends only a little time directly addressing this question. He argues that the Neanderthal genome can serve as a counterpoint to our own. It enables Paabo and his colleagues to draw up a list of mutations that our ancestors acquired after they split from Neanderthals. Among those mutations may be changes that led to our capacity for language, symbolic thought or the other traits that make us uniquely human.

Popular-archaeology.com states:

 These genes may hold key clues to the behavioral differences between modern humans and the extinct, archaic human species. According to Svante Pääbo of the Max Planck Institute, they could constitute “a catalog of genetic features that sets all modern humans apart from all other organisms, living or extinct.”

“I believe,” he added, “that in it hide some of the things that made the enormous expansion of human populations and human culture and technology in the last 100,000 years possible.”

Steve Hsu writes:

What Homo Sapiens accomplished in 50-100k years far outstrips Neanderthal accomplishments over a much longer period of time.

So Pääbo is hoping that by studying the genomic variants that distinguish virtually all anatomically modern humans from virtually all Neanderthals, he’ll discover why our species colonized the entire planet, invented civilization and went to the moon, while Neanderthals languished in the stone age for hundreds of thousands of years.

All this assumes the biggest evolutionary changes occured after we split from Neanderthals some 500,000 years ago, but before human races split from each other, maybe 70,000 years ago for people outside of sub-Saharan Africa, maybe 150,000 to 250,000 years ago for the various groups in sub-Saharan Africa .

But what if the biggest changes are very recent? In 2007 sciencemag.org stated:

Plentiful food has made it easier than ever before to survive and reproduce in many parts of the world, so it’s tempting to think that our species has stopped evolving. But a controversial new study says that isn’t so. Far from slowing down, human evolution has sped up in the past 40,000 years and has become 100 times faster in the past 5000 years alone, according to the analysis.

So should we think of the last 5000 years as half a million years of evolution?

From a 2007 article in REUTERS:

Human evolution has been moving at breakneck speed in the past several thousand years, far from plodding along as some scientists had thought… In fact, people today are genetically more different from people living 5,000 years ago than those humans were different from the Neanderthals who vanished 30,000 years ago …

But if they were more similar to Neanderthals, why are they considered members of our own species, and if so much evolution has occurred in the last 5,000 years, how did we manage to look fully modern by 195,000 years ago (the age when our species first categorically appears in the fossil record)?