24.11.06

Out of Africa

Modern Humans
Fully modern human beings (Homo sapiens) evolved about 150,000 years ago in Africa and soon spread across the globe.16 With the advent of agriculture, about 23,000 years ago, humans began to gather seeds and cultivate crops to provide a more consistent food supply.17 Our ancestors occasionally killed animals for their flesh, but they still received most of their nutrition from plant sources. Until recently, only the wealthiest people could afford to feed, raise, and slaughter animals for their flesh. Consequently, prior to the 20th century, only the rich died from diseases like heart disease, obesity, and strokes. We humans are strange primates. We walk on two legs, carry around enormous brains and have colonized every corner of the globe. Anthropologists and biologists have long sought to understand how our lineage came to differ so profoundly from the primate norm in these ways, and over the years all manner of hypotheses aimed at explaining each of these oddities have been put forth. But a growing body of evidence indicates that these miscellaneous quirks of humanity in fact have a common thread: they are largely the result of natural selection acting to maximize dietary quality and foraging efficiency. Changes in food availability over time, it seems, strongly influenced our hominid ancestors. Thus, in an evolutionary sense, we are very much what we ate.




Out of Africa view: modern humans evolved in Africa before colonizing the world.
2) Recent African origin
proposes that modern humans evolved once in Africa between 100 - 200 thousand years ago
modern humans subsequently colonised the rest of the world without genetic mixing with archaic forms
supported by the majority of genetic evidence
Naked ape or God's special project?,
Everyone wants to be special. In big families, children vie for the place of momma's little boys or girls; in the army, every soldier carries a marshal's staff in his backpack. There is barely any nation (mature enough to identify itself as a nation) which successfully resisted, throughout its history, messianic ideas. The worst political nightmares of the last century arose from our burning desire to be special, and to prove so to all other untermenschen.
But let's face it, we are not special. During the last decades, the civilization entered a phase when it can destroy itself - by military or industrial means. We proudly predict the end of the world. But the world has existed for billions of years before us, and will safely do without us. Even in the worst-case scenario of a nuclear Armageddon, cockroaches will survive. It will not be the end of the world. Just the end of us. Big deal. It's just one species.

It seems to be pretty important to come to terms with being ordinary. To find a proper place for ourselves in the world. To stop misrepresenting ourselves. Once Copernicus shifted Earth from the central place in the universe, astronomy ceased to be a fairy tale, and eventually space travel became possible. Everybody won, in the long run.

The first father of modern Western thought, Aristotle, seemed to be aware of this need. (Though I am always wary about interpretations of Aristotle in modern science books - his writings are not perfectly preserved and extremely cryptic, and blurred by twenty-five hundred years of interpretations.) The second father of modern Western thought, Descartes, did away with it, reinforcing the ideas of our special position, of God's special treatment of our species, and rejecting any continuity between (other) animals and ourselves.

We are still struggling with the consequences. Darwin offered a bridge across this yawning gap, but old convictions die hard. We are still extremely uncomfortable with the idea of our connection with the rest of the living world.

just one question: do animals have culture? To answer that, we need to define terms, of course. He defines culture as non-genetically transmitted information. And then he easily says - Yes, they do. Songbirds have dialects (roughly speaking, nightingales and rossignols do not sing the same tunes). Japanese monkeys in a certain colony on a certain island wash sweet potatoes in the sea. Chimpanzees of a certain colony use stone tools to crack coconuts open. They are not born this way. They learn it from each other and pass it down to the next generations. Just like us. We are not born with driving skills, for example. We cannot possibly be, such skills have been necessary for only about one hundred years, that's not even recognizable as evolutionary time. But we learn to drive, some better than others; and chimps learn to crack coconuts. There are human populations which do not need to drive, and they don't. There are chimp populations where coconuts do not grow, and they don't have these skills. Simple, isn't it.

Simple. But consider the implications. All difference between the ape and the sushi master becomes quantitative. We find ourselves not on the pinnacle of God's creation, but rather in a link connected to the endless chain. We are forced to reconsider everything that we deem exclusively human. And the more we consider it, the weaker our case for uniqueness. Altruism? You can routinely train dogs to blow up enemy's tanks. There is no reward, no evolutionary need that justifies such actions. Language? We hardly know what language is; we do not know when, how or why it originated; we do not have bullet-proof ways to separate animals' communication means from ours. Art? Humans have lived for thousands of years without any trace of art; either our definition of "humans" is seriously flawed, or art is not crucial for our biological existence. And then again, there are ape painters, and they do it for their own pleasure. Social structures? There are animals with such sophisticated social life that our states and parties (both senses) seem a joke in comparison.

It is not bad to be self-centered, it is bad to be self-absorbed. Once we understand our limitations, things will go more smoothly. It is good for us to know that there is no metaphysical divide between the ape and the sushi master. Genealogy is a fashionable subject. People dig up old archives and trace their ancestry to the last visible boundaries. They also like to imagine who they were in their previous lives (always someone important). The catch there is that any traceable genealogy goes back only for so many generations. The best possible results, realistically achievable only if you belong to some royal family, go back a thousand years. With gaps, blots, smudges and dubious paternal issues. Besides, in this man's world of ours, it is almost impossible to track down the maternal line of your family beyond what your great-grandmother remembered, if you were lucky to have one.
However, there is one gene, the mitochondrial DNA, which is preserved almost untouched through countless generations for many thousand years. And it is transferred exclusively along the maternal lines.
Dr. Sykes's book traces the ancient ancestry of all Europeans, reducing their multiple lineages to just seven women who lived scores of thousands years ago. They are our genetic proto-mothers. If you are curious enough, you can even try to find out whose descendant you are.
These seven women, in their turn, are remotely connected to a woman who lived long, long before them somewhere in Africa, and who was the possible direct ancestor of all now living human beings. So, in a sense, we are all indeed brothers and sisters. And our common relatives lived much more recently than previously thought.
"The Seven Daughters of Eve" destroys any biological notions of race or nationality, demoting them to pure statistical abstractions. The mitochondrial trace is, of course, just one of numerous other possible lineages - remember, there had to be an unbroken sequence of daughters all until your mother for this gene to end up in your body. But it only makes the point stronger: should we try other routes, the number of our inter-relations will only increase. We are even more closely related than the mitochondrial story suggests.
Dr. Sykes did not invent either mitochondrial DNA analysis or population genetics; he just combined the two, and, using these powerful tools, made several important discoveries. For example, his findings confirmed the Asian provenance of Polynesians, as opposed to American origin (which was a controversial but vocal hypothesis, advocated, among others, by Thor Heyerdal); disproved the well-established view that the original population of Europe was overwhelmed and supplanted by intruders from Near East; and showed that all modern Europeans - actually, all modern people - come from a common (and recent) African source, and did not develop independently in Asia, Europe and on other continents from apelike ancestors. The Neanderthals, who lived in Europe side by side with humans of modern built, and even had slightly bigger brains than we do, did not leave any progeny; they died out completely. We are not their descendants. We come from Africa.
There are other amazing stories, and each of them made front-page headlines at one point or the other; the Oxford-based team of Dr. Sykes discovered living descendants of the Iceman, found in the Alps, and of the Cheddar Man, found in English caves; and they contributed to the identification of the remains of the Russian royal family, executed by Bolsheviks in 1918.
only serious flop for my view is when we start describing hypothetical lives of the seven women – seven genetic mothers, who lived eons ago.

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