The 10,000 Year Explosion: How Civilization Accelerated Human Evolution [Hardcover]

Gregory Cochran (Author), Henry Harpending (Author)

Book Description

Publication Date: January 27, 2009

Resistance to malaria. Blue eyes. Lactose tolerance. What do all of these traits have in common? Every one of them has emerged in the last 10,000 years.

Scientists have long believed that the “great leap forward” that occurred some 40,000 to 50,000 years ago in Europe marked end of significant biological evolution in humans. In this stunningly original account of our evolutionary history, top scholars Gregory Cochran and Henry Harpending reject this conventional wisdom and reveal that the human species has undergone a storm of genetic change much more recently. Human evolution in fact accelerated after civilization arose, they contend, and these ongoing changes have played a pivotal role in human history. They argue that biology explains the expansion of the Indo-Europeans, the European conquest of the Americas, and European Jews' rise to intellectual prominence. In each of these cases, the key was recent genetic change: adult milk tolerance in the early Indo-Europeans that allowed for a new way of life, increased disease resistance among the Europeans settling America, and new versions of neurological genes among European Jews.

Ranging across subjects as diverse as human domestication, Neanderthal hybridization, and IQ tests, Cochran and Harpending's analysis demonstrates convincingly that human genetics have changed and can continue to change much more rapidly than scientists have previously believed. A provocative and fascinating new look at human evolution that turns conventional wisdom on its head, The 10,000 Year Explosion reveals the ongoing interplay between culture and biology in the making of the human race.
 

Editorial Reviews

From Publishers Weekly

Arguing that human genetic evolution is still ongoing, physicist-turned-evolutionary biologist Cochran and anthropologist Harpending marshal evidence for dramatic genetic change in the (geologically) recent past, particularly since the invention of agriculture. Unfortunately, much of their argument-including the origin of modern humans, agriculture, and Indo-Europeans-tends to neglect archaeological and geological evidence; readers should keep in mind that assumed time frames, like the age of the human species, are minimums at best and serious underestimates at worst. That said, there is much here to recommend, including the authors' unique approach to the question of modern human-Neanderthal interbreeding, and their discussion of the genetic pressures on Ashkenazi Jews over the past 1,000 years, both based solidly in fact. They also provide clear explanations for tricky concepts like gene flow and haplotypes, and their arguments are intriguing throughout. Though lapses in their case won't be obvious to the untrained eye, it's clear that this lively, informative text is not meant to deceive (abundant references and a glossary also help) but to provoke thought, debate and possibly wonder.
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From Booklist

Cochran and Harpending dispute the late Stephen Jay Gould’s assertion that civilization was “built with the same body and brain” Homo sapiens has had for 40,000 years. Humanity has been evolving very dramatically for the last 10,000 years, they say, spurred by the very civilizational forces launched by that evolution. They initially retreat, however, to Gould’s 40,000-year benchmark to consider how H. sapiens replaced H. neanderthalensis and to argue for genetic mixing such that modern humans got from Neanderthals the innovative capacity for civilization. Later, agricultural life created problems necessitating adaptations, most importantly to disease and diet, that persist to this day among inheritors of the populations that made them. Lighter skin and eye color arose from other genetic reactions to environmental challenges, and less immediately obvious changes further discriminated discrete populations, as recently as late-eighteenth-century Ashkenazi Jews, among whom intelligence burgeoned in, Cochran and Harpending contend, adaptive response to social pressure. A most intriguing deposition, without a trace of ethnic or racial advocacy, though directed against the proposition that “we’re all the same.” --Ray Olson

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Product Details

• Hardcover: 304 pages
• Publisher: Basic Books (January 27, 2009)
• Language: English
• ISBN-10: 0465002218
• ISBN-13: 978-0465002214
• Product Dimensions: 6.1 x 1.1 x 9.3 inches
• Shipping Weight: 13.6 ounces
• Average Customer Review: 4.2 out of 5 stars  See all reviews (79 customer reviews)
• Amazon Best Sellers Rank: #601,191 in Books (See Top 100 in Books)

Most Helpful Customer Reviews

180 of 189 people found the following review helpful

5.0 out of 5 stars A meal of many courses January 21, 2009

By R. Razib

Format:Hardcover

I read *The 10,000 Year Explosion* in one sitting. It's an incredibly dense 300 pages, synthesizing population genetics, classical history, archaeology and paleontology (to name a few fields). But the prose is straightforward and clear. The relatively abstruse nature of some of the intellectual framework means that many readers may encounter population genetics for the first time in their life, but for those who are less than enchanted by algebra these excursions are optional and one can safely "hum through" them and get to the meat.

And there is quite a bit of meat. Many books on human evolution have one main narrative arc; e.g., the Out-of-Africa migration, or the discovery of the Hobbits of Flores. In contrast, works which focus on world events tend to take a broad "peoples & places" vantage point, with little concern for non-human dynamics. As the authors note, *The 10,000 Year Explosion* is actually a work of genetic history, so naturally its purview is broader and its foundation more varied than is normally the case with narratives which attempt to sketch out the shape of human history. In fact, it is fundamentally different than other popular works of genetic history, such as *The Journey of Man* or *The Seven Daughters of Eve*. While those books attempt to infer prehistoric population movements from the patterns of particular genes today, *The 10,000 Year Explosion* aims to give full treatment to the evolutionary power of natural selection in shaping human history. Human migrations may shape genetics, but *The 10,000 Year Explosion* shows how genetics may shape human migrations, how culture may shape genetics, and how genetics may shape culture!

The abstract models which serve as the theory are fleshed out with specific case studies and familiar dynamics.... For example, how did the Indo-European language family get to be so geographically expansive? There might be a genetic reason for this having to due with a particular adaptation. *The 10,000 Year Explosion* outlines the possibilities in detail. In a more general vein, the authors offer that agriculture might have sped up evolution, not resulted in its end. This seemingly counterintuitive claim on the face of it is eminently logical upon further inspection, and in fact has some empirical support. Finally, *The 10,000 Year Explosion* puts the spotlight on even relatively recent events. For example, the peculiarities of the genetic history of the Ashkenazi Jews over the past 1,000 years, and the impact of this upon the occupational profiles of the Ashkenazi Jews today.

*The 10,000 Year Explosion* is bursting with ideas big & small. Some of them require a bit of algebra for clarity, but much of it is amenable to common sense aided with illustration. Many of the ideas will have a "Why, that makes total sense!" quality to them, while other claims are of a type that many may find troubling if true. This is a book which will enlighten even if it infuriates. Read more ›

96 of 104 people found the following review helpful

5.0 out of 5 stars Darwin's History Book January 22, 2009

By Joel

Format:Hardcover

The human species, according to Cochran and Harpending, is more interesting and more varied than would be imagined. They point out that the pace of human evolution accelerates linearly with population size (more people means more mutations), and that man has domesticated himself in many of the same ways that he has domesticated his plants and animals. The last 10,000 years really have seen an explosion of evolutionary change. There is the story of how lactose tolerant Indo-Europeans spread milk-drinking with blood and fire, why the Ashkenazi suffer from crippling genetic diseases at an unexpectedly high rate while winning 25% of Nobel Prizes in the last century, and how the Spanish really brought down the Aztecs and the Incas. This book is really the anti-"Guns, Germs, and Steel." The real accidents of history are matters of gene flow and chance mutation. This book compresses an astounding number of ideas into a few short chapters. As with the other reviewer, I was caught up by the active and engaging prose style, causing me to breeze through the book in 2-3 hours.

89 of 97 people found the following review helpful

5.0 out of 5 stars The Past Is A Foreign Country February 7, 2009

By William Holmes VINE™ VOICE

Format:Hardcover|Amazon Verified Purchase

Despite the complexity of the subject, "The 10,000 Year Explosion" is clearly written and compellingly argued. The book is devoted to refuting the idea that human evolution stopped 10,000 or 50,000 years ago, as some have argued. Rather, humans are constantly adapting to diseases, cultural innovations, and myriad other changes in the environment. As Cochran and Harpending point out in the Overview to their book, "humans have changed significantly in body and mind over recorded history. Sargon and Imhotep were different from you genetically as well as culturally."

At some level, the idea is plainly correct. Sickle cell anemia, for example, results from an adaptation to malaria. Those who had the gene were more likely to live long enough to have offspring, so the genes that code for malaria resistance are much more frequent in populations originating from areas where malaria has been historically common.

The same principle explains why the New World's inhabitants were almost completely wiped out by diseases imported from the Old World--by some estimates, mortality approached 90% of the pre-1492 population of North America and South America. The denizens of the Old World had been pastoralists and farmers much longer than their New World counterparts, and so had been exposed to a host of nasty diseases that originate from domesticated animals (e.g., smallpox). The farmers who were lucky enough to have a genetic adaptation that could resist the diseases passed the adaptation along to their offspring, and over hundreds or thousands of years the genetic defense swept through the whole population. By the time Columbus reached the New World, he and has compatriots had evolved to resist the Old World's diseases.... In the New World, the Native American population had turned to agriculture relatively recently and didn't have the same suite of domesticated animals as the inhabitants of the Old World. Native Americans had evolved no genetic defenses against the diseases brought by the Europeans, and millions died in the space of a few decades. (The tables were turned on the Europeans who ventured into Africa, who were genetically ill-equipped to deal with tropical diseases like malaria.)

Cochran and Harpending's discussion of the Ashkenazim is bound to be more controverial and disturbing. The authors argue that, during the Middle Ages, the Ashkenazi Jews were, for various cultural reasons, a genetically isolated population that could make a living only in certain demanding careers, such as money lending and asset management. All of these occupations rewarded great intellectual ability, so over a period of hundreds of years, the Ashkenazi Jews became smarter on average than other Europeans. (According to the authors, the average IQ of the Ashkenazi Jews is 112, about three quarters of a standard deviation above the European mean.) This pushed the normal distribution of IQ scores among the Ashkenazi to the right, so the Ashkenazi were rewarded with a disproportionate number of geniuses relative to the size of their population. As further support for their hypothesis, the authors point out that the genetic diseases like Tay-Sachs that are associated with the Ashkenazi population seem to be errant expressions of genes that enhance the performance of the brain and central nervous system.

Of course, many of us become very uncomfortable when genetics seems to suggest that one human population might, on average, be more intelligent than another. Arguments about the alleged superiority of one group over another have been used to horrible effect in human history. But the authors are optimists, not racists. Pointing out that there is a unique genetic adaptation among the inhabitants of the village of Limone sul Garda that greatly reduces the risk of coronary disease, the authors argue that "some of the results of history's experiments may even aid us in more ambitious efforts aimed at increasing human life spans and cognitive abilities." Fine up to a point, but we must always be wary of the enthusiasms of those who would twist such hopeful conclusions into an argument for a new form of eugenics. Read more ›

24 of 26 people found the following review helpful

5.0 out of 5 stars Flush with the excitement of new findings March 26, 2009

By Graham H. Seibert TOP 1000 REVIEWERVINE™ VOICE

Format:Hardcover|Amazon Verified Purchase

The authors piece together evidence from their wide-ranging, largely self-taught fields of expertise to flesh out their thesis that cultural and biological evolution go hand-in-hand. It seems probable that the publicity they got for their article two years ago on Ashkenazi Jewish intelligence convinced them that the time was right for a book. The Jewish piece, relatively little changed, appears as their final chapter.

The findings are new and the book feels a little raw. The authors know that many of their findings are subject to restatement on the basis of further research. One has the feeling that their objective is not to have the final word, but to reframe the argument. Intelligence researchers and others have long contended that there are statistically significant, measurable differences among populations. The essence of the counterargument has been "No, that can't be. There has not been enough time." Cochran and Harpending cite a vast body of evidence to the effect that yes, evolution can create vast differences among populations in the timeframe under discussion. They cite the great variety to be observed among dogs and other animals, and cultivated crops, just within the last century or two. The authors claim that the thesis that there have been no significant evolutionary changes in Homo sapiens over the past 50,000 years is about as likely as dumping a bag full of silver dollars on the floor and observing that they all land on edge. Simply impossible.

They are bold to suggest that interbreeding with Neanderthals may have sparked what they call the "great leap forward" and others refer to as the "Neolithic Revolution." They argue two ways.... First, they establish the proximity of Neanderthals and modern humans for about 10,000 years during this timeframe, roughly 40,000 years ago. They point to evidence, admittedly rather meager, that there was cultural exchange between the hominids, and on the basis of what we know about ourselves, if they were that close, they almost inevitably interbred. They then argue by analogy with several better studied examples of introgression - the recombination of breeding groups that had become isolated - to argue that while modern humans coming out of Africa may have been overall superior competitors, it is quite likely that they could have benefited by borrowing a few well adapted genes from the Neanderthals. Whether or not the Neanderthal thesis turns out to be valid, the presentation in itself is very informative.

Harpending and Cochran frequently cite Jared Diamond. Surprisingly, some very prominent people one expects would be sympathetic to their findings are absent from their bibliography, among them Steven Pinker, Luigi Cavalli Sforza, Spencer Wells, Nicholas Wade, and even Philippe Rushton, whom they thank in their forward. They appear more driven to put forward provocative new ideas, and less affected by the fear of being shown to be partially an error.

The authors are extremely aware that they are baiting the bears of political correctness. Their thesis directly challenges the dogma of the American Anthropological Association, which stands behind its resolution that "WHEREAS all human beings are members of one species, Homo sapiens, and WHEREAS, differentiating species into biologically defined "races" has proven meaningless and unscientific as a way of explaining variation (whether in intelligence or other traits), THEREFORE, the American Anthropological Association urges the academy, our political leaders and our communities to affirm, without distraction by mistaken claims of racially determined intelligence, the common stake in assuring equal opportunity, in respecting diversity and in securing a harmonious quality of life for all people.

Keeping their exposure to a minimum, the authors make few observations on the broader implications of their findings. They make the commonsense observation that peoples who have dealt in farming and commerce for many millennia probably evolved skills that give them a competitive advantage. They dryly note that the Amerindians' lack of such historical experience perhaps "... underlies a current wave of discontent with liberal economic policies in South America." There is certainly more to be said, and one suspects the authors would readily tell it in a cocktail party conversation, but it would defeat their purpose to invite imbroglios such as greeted "The Bell Curve." Their objective is to get research pointed in more fruitful directions. As a former member of the American Educational Research Association, I say "Amen." We have spent far too much time, money, and psychic energy time trying to solve insoluble problems because we refuse to examine untenable hypotheses.

The most part prominent scientist to debunk the notions that human populations differ significantly in any fundamental way, and by the way, that IQ testing is meaningless, was the late Stephen Jay Gould. Cochran and Harpending take Gould all on directly on several occasions.

Take this book for what it is, an exposition of exciting new findings and an invitation to apply what we are learning in the field of genetics to bodies of knowledge within other disciplines, among them anthropology, paleontology, psychology, and history. I am sure that their hope is that in the end these studies will be able to enlighten public policy. Read more ›