10-28-2004, 12:23 AM
Much has been made recently of a 'beachcombing' lifestyle among the first modern Africans as a motive for spreading out of Africa and around the Indian Ocean. For most of their first 2 million years on Earth, humans were roaming the savannah as hunter-gatherers. Like the Kalahari of southern Africa, they exploited the rich nutritional value of group-hunted game, supplemented by salads of roots, fruit, and leaves. As the major glaciation of 130,000 - 190,000 years ago began to reduce their savannah range, someone had the idea of foraging and eating shellfish and other marine produce from the beach. It is always possible that beachcombing started even earlier, but since the beaches are now under water, we will never know. Such a diet, being rich in protein, is nutritious, good for the brain, and easier to obtain than game. Beach tucker has the added advantage of remaining available when the savannah dries up during an ice age.
Evidence for such beachcombing is unexpectedly easy to assess, since characteristic piles of split shells (shell middens) are left behind. There is, however, a problem in knowing just how long humans have been doing it. Shell middens are generally found just above the high-tide line, but for most of the past 200,000 years sea levels have been many metres below today's beaches. This means we would expect to miss most ancient middens except those laid down during the high sea levels of an interglacial, such as the one 125,000 years ago.
Neanderthals combed beaches in Spain and Italy 60,000 years ago, so it is possible that they brought the practice with them from Africa. Until recently, however, the earliest evidence for African beachcombing came from the Klasies River mouth in South Africa, dated to between 100,000 and 115,000 years ago. In 2000, however, new evidence was discovered for early beachcombing at Abdur on the Eritrean west coast of the Red Sea, just to the north of the Gate of Grief. Dated to 125,000 years ago, at the peak of the Eemian interglacial, the same beach site yielded butchered remains of large mammals, indicating a mixed diet. The implements, which included blades made from obsidian, a volcanic glass, are most likely to have been made by modern humans.
The great interest in this site on the Red Sea is twofold: it provides us with the oldest evidence for beachcombing anywhere and it is very close to the southern route out of Africa. Both aspects feed into an attractive model, which may be called the 'beach-buggy to Australia'. We get a compelling story of beachcombers multiplying until their patch of beach could support them no longer, then moving on to the next unexploited beach, and so on. By such rapid progression, once over the Red Sea the vanguard would just have followed the coast of the Indian Ocean, eating their way right down to Indonesia within 10,000 years. The low sea levels of the time would have allowed a dry walk from Aden to the tip of Java, and then easy island hops to Australia, where shell middens are found from the earliest traces of human habitation.
I am pretty sure that this model of the early colonization of Australia is correct, but the dates have to fit, not only for the archaeological evidence but also for the <b>molecular clock on the gene tree for all the other Eurasian dispersals. If, on top of this beach buggy model, we impose only a single out-of-Africa exodus to colonize both Australia and the rest of the world, we can start to make strong predictions for the order and dates of colonization en route of India, Southeast Asia, and the parallel movement to New Guinea. These predictions should be the test of the theory.</b>
EUROPEAN ORIGINS
As we have seen, the teasing issue of European origins is not just a matter of whether the future Europeans migrated out of Africa separately from the future Asians and Australians, or of just burying the myth that they were the first humans to show modern behaviour. It is more than that. Where did their extraordinary flowering of culture originate? Was it entirely home-grown, or was it imported? Why do some archaeologists argue for several different early cultural inputs to Europe in the period between 20,000 and 50,000 years ago - even one from the East? It can be argued that there are precise male and female genetic markers which parallel two different cultural waves that flowed in succession over the European archaeological record of the 25,000 years leading up the Last Glacial Maximum. These reveal that an 'Eastern' origin was no wild guess.
The ancestors of Europeans, the N (or Nasreen) clan, belonged to one of the first branches off the single exodus shoot which arrived in southern Arabia perhaps 80,000 years ago. <b>In spite of this secure position at the root of the Asian maternal genetic tree, the Europeans' ancestors had to wait tens of thousands of years in South Asia. </b>They waited until at least 50,000 years ago, when a moist, warm phase greened the Arabian Desert sufficiently to open the Fertile Crescent and allowed them to migrate north-westwards towards Turkey and the Levant. Such constraints had not affected their cousins - the vanguard of beach-combers who pressed on round the Indian Ocean coast to Southeast Asia and Australia. They arrived in Australia over 60,000 years ago, long before Europe was colonized.
<b>From an Asian point of view, Europe is an inaccessible peninsula jutting out north-west from the Old World, a geographical cul-de-sac. Genetically as well as geographically, Europeans are, similarly, a side-branch of the out-of-Africa human tree. Because the first non-African modern humans were Asians, 'peninsular Europe' was more likely to have been a recipient and beneficiary of the seeds of the earliest Upper Palaeolithic cultural innovations rather than their homeland. <span style='font-size:14pt;line-height:100%'>From this perspective it deconstructs the archaeological/anthropological myth of a major human biological revolution defined in Europe and the Levant, with everyone else in the world following the European lead</span>.</b>
The Fertile Crescent corridor opens
Our maternal gene tree suggests ultimately a 50,000-year-old South Asian origin for our oldest European founders. To arrive further north in Anatolia over 50,000 years ago they would have had to skirt the Libyan and Arabian Deserts, using the Fertile Crescent as a corridor. Given the rather generous margins of error on the molecular clock, for that trek up from the Zagros Mountains and Gulf marshes in south-west Iran, we should look at their migration from the perspective of climatic opportunity which, like the rings on a tree, gives us the most accurate dating. <i>The Fertile Crescent corridor was dry, and was closed during much of the last 100,000 years, opening only briefly during climatic improvements called 'interstadials'.</i>
Between 55,000 and 65,000 years ago the world went through a period of almost unremitting cold and dryness. During this time the Fertile Crescent corridor was shut. <b>Then, from 56,000 years ago onwards, there followed in quick succession a run of four warm and wet periods. The last of these, 51,000 years ago, was the warmest and most prolonged, lasting nearly 5,000 years. In fact, so warm and wet was this interstadial that the Indian monsoon was even wetter than it is today, and so, apart from the opening of the Fertile Crescent corridor, dry areas of the Levant such as the Negev Desert became potentially habitable for our Upper Palaeolithic tool-makers. If there was ever a time for us to multiply in South Asia and spread up to the Levant, this was it. </b>The climatic and archaeological clock timings converge on the lush period between 45,000 and 50,000 years ago. So it looks as though the molecular clock's timing for the arrival of the earliest daughter lines of Nasreen and their families in the Levant is not far off.
Europe's Asian roots
<b>This trip through genetic and human time has suggested two extraordinary conclusions: first, that the Europeans' genetic home-land was originally in South Asia in the Pakistani Gulf region over 50,000 years ago; and second, the Europeans' ancestors followed a corridor from the Gulf through Kurdistan, known as the Fertile Crescent, which opened 51,000 years ago, allowing movement up through Turkey and eventually to Bulgaria and Southern Europe.</b> This seems to coincide with the Aurignacian cultural movement into Europe. The second early route from South Asia to Europe may have been up the Indus into Kashmir and on to Central Asia, where perhaps more than 40,000 years ago hunters first started bringing down game as large as mammoths. Some of these hunters with their elaborate technical skills may then have moved westward across the Urals to European Russia and on to the Czech Republic and Germany. A more conservative view of this eastern invasion might be that the Trans-Caucasus, rather than Central Asia, was the earliest route of modern human entry into Russia.
Evidence for such beachcombing is unexpectedly easy to assess, since characteristic piles of split shells (shell middens) are left behind. There is, however, a problem in knowing just how long humans have been doing it. Shell middens are generally found just above the high-tide line, but for most of the past 200,000 years sea levels have been many metres below today's beaches. This means we would expect to miss most ancient middens except those laid down during the high sea levels of an interglacial, such as the one 125,000 years ago.
Neanderthals combed beaches in Spain and Italy 60,000 years ago, so it is possible that they brought the practice with them from Africa. Until recently, however, the earliest evidence for African beachcombing came from the Klasies River mouth in South Africa, dated to between 100,000 and 115,000 years ago. In 2000, however, new evidence was discovered for early beachcombing at Abdur on the Eritrean west coast of the Red Sea, just to the north of the Gate of Grief. Dated to 125,000 years ago, at the peak of the Eemian interglacial, the same beach site yielded butchered remains of large mammals, indicating a mixed diet. The implements, which included blades made from obsidian, a volcanic glass, are most likely to have been made by modern humans.
The great interest in this site on the Red Sea is twofold: it provides us with the oldest evidence for beachcombing anywhere and it is very close to the southern route out of Africa. Both aspects feed into an attractive model, which may be called the 'beach-buggy to Australia'. We get a compelling story of beachcombers multiplying until their patch of beach could support them no longer, then moving on to the next unexploited beach, and so on. By such rapid progression, once over the Red Sea the vanguard would just have followed the coast of the Indian Ocean, eating their way right down to Indonesia within 10,000 years. The low sea levels of the time would have allowed a dry walk from Aden to the tip of Java, and then easy island hops to Australia, where shell middens are found from the earliest traces of human habitation.
I am pretty sure that this model of the early colonization of Australia is correct, but the dates have to fit, not only for the archaeological evidence but also for the <b>molecular clock on the gene tree for all the other Eurasian dispersals. If, on top of this beach buggy model, we impose only a single out-of-Africa exodus to colonize both Australia and the rest of the world, we can start to make strong predictions for the order and dates of colonization en route of India, Southeast Asia, and the parallel movement to New Guinea. These predictions should be the test of the theory.</b>
EUROPEAN ORIGINS
As we have seen, the teasing issue of European origins is not just a matter of whether the future Europeans migrated out of Africa separately from the future Asians and Australians, or of just burying the myth that they were the first humans to show modern behaviour. It is more than that. Where did their extraordinary flowering of culture originate? Was it entirely home-grown, or was it imported? Why do some archaeologists argue for several different early cultural inputs to Europe in the period between 20,000 and 50,000 years ago - even one from the East? It can be argued that there are precise male and female genetic markers which parallel two different cultural waves that flowed in succession over the European archaeological record of the 25,000 years leading up the Last Glacial Maximum. These reveal that an 'Eastern' origin was no wild guess.
The ancestors of Europeans, the N (or Nasreen) clan, belonged to one of the first branches off the single exodus shoot which arrived in southern Arabia perhaps 80,000 years ago. <b>In spite of this secure position at the root of the Asian maternal genetic tree, the Europeans' ancestors had to wait tens of thousands of years in South Asia. </b>They waited until at least 50,000 years ago, when a moist, warm phase greened the Arabian Desert sufficiently to open the Fertile Crescent and allowed them to migrate north-westwards towards Turkey and the Levant. Such constraints had not affected their cousins - the vanguard of beach-combers who pressed on round the Indian Ocean coast to Southeast Asia and Australia. They arrived in Australia over 60,000 years ago, long before Europe was colonized.
<b>From an Asian point of view, Europe is an inaccessible peninsula jutting out north-west from the Old World, a geographical cul-de-sac. Genetically as well as geographically, Europeans are, similarly, a side-branch of the out-of-Africa human tree. Because the first non-African modern humans were Asians, 'peninsular Europe' was more likely to have been a recipient and beneficiary of the seeds of the earliest Upper Palaeolithic cultural innovations rather than their homeland. <span style='font-size:14pt;line-height:100%'>From this perspective it deconstructs the archaeological/anthropological myth of a major human biological revolution defined in Europe and the Levant, with everyone else in the world following the European lead</span>.</b>
The Fertile Crescent corridor opens
Our maternal gene tree suggests ultimately a 50,000-year-old South Asian origin for our oldest European founders. To arrive further north in Anatolia over 50,000 years ago they would have had to skirt the Libyan and Arabian Deserts, using the Fertile Crescent as a corridor. Given the rather generous margins of error on the molecular clock, for that trek up from the Zagros Mountains and Gulf marshes in south-west Iran, we should look at their migration from the perspective of climatic opportunity which, like the rings on a tree, gives us the most accurate dating. <i>The Fertile Crescent corridor was dry, and was closed during much of the last 100,000 years, opening only briefly during climatic improvements called 'interstadials'.</i>
Between 55,000 and 65,000 years ago the world went through a period of almost unremitting cold and dryness. During this time the Fertile Crescent corridor was shut. <b>Then, from 56,000 years ago onwards, there followed in quick succession a run of four warm and wet periods. The last of these, 51,000 years ago, was the warmest and most prolonged, lasting nearly 5,000 years. In fact, so warm and wet was this interstadial that the Indian monsoon was even wetter than it is today, and so, apart from the opening of the Fertile Crescent corridor, dry areas of the Levant such as the Negev Desert became potentially habitable for our Upper Palaeolithic tool-makers. If there was ever a time for us to multiply in South Asia and spread up to the Levant, this was it. </b>The climatic and archaeological clock timings converge on the lush period between 45,000 and 50,000 years ago. So it looks as though the molecular clock's timing for the arrival of the earliest daughter lines of Nasreen and their families in the Levant is not far off.
Europe's Asian roots
<b>This trip through genetic and human time has suggested two extraordinary conclusions: first, that the Europeans' genetic home-land was originally in South Asia in the Pakistani Gulf region over 50,000 years ago; and second, the Europeans' ancestors followed a corridor from the Gulf through Kurdistan, known as the Fertile Crescent, which opened 51,000 years ago, allowing movement up through Turkey and eventually to Bulgaria and Southern Europe.</b> This seems to coincide with the Aurignacian cultural movement into Europe. The second early route from South Asia to Europe may have been up the Indus into Kashmir and on to Central Asia, where perhaps more than 40,000 years ago hunters first started bringing down game as large as mammoths. Some of these hunters with their elaborate technical skills may then have moved westward across the Urals to European Russia and on to the Czech Republic and Germany. A more conservative view of this eastern invasion might be that the Trans-Caucasus, rather than Central Asia, was the earliest route of modern human entry into Russia.