Favorable mutations are rare, and many of those that do occur are lost by chance. In the small human populations of the Old Stone Age, establishing such mutations typically took hundreds of thousands of years. It’s not that it took that long for favorable mutations to spread - the problem was generating them in the first place.
But as the human population sizes increased, particularly with the advent of agriculture, favorable mutations occurred more and more often. Sixty thousand years ago, before the expansion out of Africa, there were something like a quarter of a million modern humans. By the Bronze Age, 3,000 years ago, that number was roughly 60 million. Favorable mutations that had previously occurred every 100,000 years or so were now showing up every 400 years.
Gregory Cochran and Henry Harpending, from The 10,000 Year Explosion, Chapter 3, “Agriculture: the Big Change,” page 65
…Greg, “accelerated evolution” has got to be the least controversial and speculative thing in that book of yours.
Criticisms of your book come largely from people questioning: your repeated use/support of human racial divisions, the stress of race’s genetic importance, the linkage of (vaguely understood) complex behavioural traits (such as cognitive ability) to a speculative relationship of unknown genes. So lets do a quick recap,
you stress the importance of genetics to racial divisions (commonly rejected in biology).
you stress the importance of genetics to cognitive ability (highly speculative).
you directly link cognitive ability to racial divisions through the concept of accelerated evolution (highly questionable).
Here is a quote from your book that seems to cover all three points.
[QUOTE=The 10,000 Year Explosion]
It has been said that the differences between human populations are superficial, consisting of surface characteristics such as skin color and hair color rather than changes in liver function or brain development. (snip) Of course, since experts can easily determine race from skeletal features, it appears that those skin-deep differences go all the way to the bone. In fact, recent work has shown that there are population differences in genes affecting brain development, which we’ll mention in Chapter 4.
It was natural for previous generations of physical anthropologists to concentrate on differences in easily observed characteristics, but that never implied that all differences would be easily observable. It was the scientists that were superficial,
not the differences.
[/QUOTE] NND (the person who started this thread), uses your book/theories to cobble together a loosely connected theory on the behavioural nature of “the races.”
[QUOTE=New Deal Democrat]
If one wants to believe that race is a social construct, that “we’re all the same under the skin,” that IQ differences don’t matter, and that there are no significant racial differences in average aptitude and behavior, one needs to believe that little or nothing has changed since the races differentiated 40,000 years ago. If one acknowledges persistent differences in performance and behavior between the races, one has to disagree.
[/QUOTE]
I’m curious, what is your opinion of his theories?
It is quite difficult to find hunter-gather groups that have had no contact with agrarian societies. Where there are such hunter-gatherers they do not seem to understand that plants grow from seeds. The Australian Aborigines were quite familiar with the seeds of various grasses, but they seemed to be unaware that the grasses and other plants grow from seeds. (Elkin, 1974, 51). http://homepages.paradise.net.nz/rochelle.f/The-Discovery-of-Agriculture.html
The main food source for the early Aborigines came from the sea. Their boats were made by cutting a long oval of bark from an eucalyptus tree and binding both ends. A fire was kept in the bottom of the boat, on clay, so that the fish could be cooked and eaten at sea. The fragility of these boats suited the nomadic way of life as they were easy to carry and just as easy to replace. The men hunted emus, kangaroo, lizards, and geese, with spears, stone axes, and a fire stick. The women did their vegetable/fruit collecting with digging sticks. They also gathered turtles, insects, nuts and honey. The only semidomestic animals were the wild, young dingos, who probably migrated with the original natives. Water holes and rain pools were the source of water. There was no indication of planned agriculture.
As the late Pleistocene processes of plant selection and environmental modification towards agriculture unfolded in the New Guinea region of the Sahul continent, the Australian Aboriginal economy of hunting and gathering was maintained, seemingly without any participation in, or diffusion of, this agricultural innovation to the north. http://www.thefreelibrary.com/The+development+of+Sahul+agriculture+with+Australia+as+bystander.-a017845241
It has long bee remarked that Australia remained a nation of nomadic hunter-gatherers while most people in the rest of the world, including New Guinea, became cultivators. Other traits of the Neolithic period, such as the domestication of animals and the use of pottery, likewise were never adopted in Australia these traits never penetrated the fifth continent…
Possible reasons put forward to explain why Australian Aborigines did not become farmers have been lack of contact with agricultural groups, cultural conservatism, hostility to newcomers, lack of suitable plants and animals to domesticate, and deliberate choice. http://www.janesoceania.com/australia_aboriginal_agriculture/index1.htm
Amazing how the false ideology of Social Darwininsm, that has tens of millon killings in its record, is still very dominant in thought of the Western Culture. And it surprised me that this ideology is still published in so many books.
It would help if instead of you telling him he’s wrong, tell him what he’s wrong about and why.
I get your comment on agriculture. There might have been some, but not much in Australia pre-European contact. As for “deforestation”, I know the Aboriginals used fire to drive prey, but did that actually cause “deforestation”? I’m sure it cause some, but how much?
And yeah, the comment about the marsupial wolf going extinct because of the dingo is a pretty wild claim, especially since his own cites contradict that claim.
Yes, the people of the mountain New Guinea are farmers, but theirs agriculture was limited to taro. Although aboriguines had sporadical contacts with New Guineans, I bet the reason why agriculture didn’t spread to Australia was that taro didn’t addapt to Australia.
People become farmers when they found suitable plants to grow. As far as I know, Australia didn’t have suitable plants at all. And with respect to domestic animals, we should remember Australia only had marsupials. As far as I know, there aren’t marsupial equivalents to cows, goats, horses or llamas at all. The only domestic animal aboriguins had were dogs, and they didn’t have anything more where to chose.
So, the problem with the development of Australia was the poverty of the land. Today all the agricultural produce and farm animals of Australia is immigrant.
Where would I start? Somebody corrected him regarding the concept of “more evolved” in the second post, and he is still repeating it. And that is the least of his errors.
Conservatively they removed at least 60% of the forest cover of the entire continent. Realistically it was closer to 90%.
“the marsupial wolf going extinct because of the dingo is a pretty wild claim”
Not at all. The arrival of the dingo in mainland Australia is believed to have caused the extinction of the thylacine (tasmanian wolf), the Tasmanian devil, and the Tasmanian native hen. The dingo showed up about 4000 years ago on the mainland, and thylacines went extinct (on the mainland) about 2000 years ago. The dingo never reached Tasmania and thylacines survived there until after European settlement.
I would call it likely, but there could conceivably have been other reasons.
A parallel: up until about 2 million years ago, most of the fair-sized predators in South America were marsupials or close relatives of marsupials. They somewhat resembled the Tasmanian Devil. When the isthmus of Panama formed, canines and felids show up, and the borhyaenids all went extinct.
Indeed. And when men entered the America, large part of the megafauna went extinct, including Mamuts that lived as south into the Western Hemisphere as Chile and Argentina. Horses, natives of the New World, also went extinct by that time.
A similar pattern is observed in the Pacific islands.
Man destroyed the environment everywhere.
Prove it. Your own cite says they actively hunted them. “Rock paintings from the Kakadu National Park clearly show that thylacines were hunted by early humans.”
But even if they didn’t do it deliberately to drive them into extinction (which wasn’t my assertion), it isjust as likely that humans played a larger role than dingoes. Or that there was a three-way synergy with climate change.
No efforts were made to exterminate dogs in Britain, either. For pretty much the same reason, I expect.
So what?
It doesn’t necessarily take a very high population density to wipe out species. Look at the Americas. All it takes is a combination of environmental stress and active hunting. And you don’t have to hunt every last member of a species to wipe them out, either.
You are getting far from my original point. My original point was that a large gene pool is likely to evolve faster than a small gene pool, and that this is one of the reasons human evolution has accelerated since 8,00 BC.