User:Adamsaifnajihussein/sandbox

Early Human MIgration--Adamsaifnajihussein (talk) 20:04, 12 May 2014 (UTC) The phenomenon of migration is rooted in human prehistory, but the question that need to be answered here is continuously appears  when we talk about migration and  history of migration. That question is Why and How early human migrated out of Africa and crossed  the earth's varied landscapes?? African's people were compelled to travel and abandon their home searching for basic needs to survive and live a better life. Far from their miserable life in the desert of Africa. when people routinely travelled over great distance  in order to search and get enough food, fresh water , a good environment and  a suitable climate for cultivate  and planting the earth and to get a secure life out of drought and  harsh life. They crossed Oceans, seas and deserts to hunt , fish and establish a livelihood, and to find suitable environment and adaptable climate .However, the first migration of early human out of Africa was toward the Arabian peninsula , east and west Asia as well, by crossing  Bab-el-Mandeb Strait on the red sea which separates present-day Yemen from Djibouti. These early beachcombers expanded rapidly along the coast to India, and reached Southeast Asia and Australia by 50,000 years ago. As researchers identify the Bab-el-Mandeb Strait on the Red Sea as the most likely departure point for the first human exodus from Africa. This narrow stretch of water between the Horn of Africa and the Arabian Peninsula or what now known as middle east ,which considered to be the gateway to the wider world, offered the shortest route to new continents. The strait would actually have been even less of a stretch than it is today (12 miles), because when Homo sapiens made the crossing some 60,000 to 70,000 years ago, sea levels were 230 feet lower due to the onset of ice age conditions that locked up water in vast polar ice caps. With some kind of raft, and perhaps a few islands to hop between, such a crossing is not difficult to imagine. and then they spread from Arabian peninsula to east and west Asia to India, Australia and then  they  migrated  into Americas by crossing the Beringia land bridge between eastern Siberia and present-day Alaska around 40,000–17,000 years ago, when sea levels were significantly lowered. As it is going to be discussed in details in the following pages. According to some scholar such as Mellar and kelin said the main reasons and factors  behind early human migration out of Africa was almost caused by the continuous changing of the  climate, the harsh and the inadequate environment which they were living in, and the changes in annual rainfall as well. As Mellar suggests that a sudden fluctuations in rainfall ,harsh environment ,inadaptable climate and the need of food  have spurred human to spread from Africa to the rest of the world  in hope to getting  better and secure life out of the starvation and drought .Actually they were looking for the basic need in life like food and water .Mellar said ,"The changes in rain pattern ,the inadaptable climate and the inadequate environment  have led humans to search for new food resources and a suitable environment where they could survive ". Also Klien stated, "perhaps precipitated by some major episodes of climatic and environment changes. However , the obvious candate would be the sharp oscillations between wetter and drier climatic conditions"  these horrible conditions would led human to migrate in hope to find a new food resources , a suitable  environment and an adequate climate for living  properly. Why and how early human migrated out of Africa and crossed the Erath's                                          Varied landscapes? The main reasons and causes of early humans migration out of Africa were driven by many factors in which scholars agreed that these factors which spurred early human migrated out of Africa and across the earth's varied landscapes. Morever, the lack of food, water , shelters, climate change ,changes on rainfall seasons and the harsh environment which they were living in , Harsh weather also contributed to migration, as flooding and drought caused problems in populated eras. in addition to the drought and the harsh deserts which forced them to abandon their homeland(Africa) ." They moved toward a different location. They moved because they had to whether their reasons were decreasing access to food and shelter, population pressure, either the wetter or the drier climate ,rainfall pattern change or environmental degradation". They moved, in other words, when the risks of staying in place exceeded the perceived dangers of venturing to a new area. Climate changes have been causes for migration. The creation of the Sahara Desert separated sub Saharan Africa from the rest of the world. However, there have been millennia of humid and arid periods, which had an impact on migration into and out of the region. Drought has forced inhabitants to leave many locations throughout the continent. Generally, these movements have been from north to south during arid periods and from south to north when conditions are relatively humid. In doing so, they hoped to better their chances of surviving, thriving, and reproducing.

At some point, probably about 80,000 years ago, some of the humans began migrating. Initially, people followed the coastlines of Africa, which were abundant in resources. They began to migrate to the Middle East, southern Asia and Australia. About 40,000 years ago, humans migrated into Europe, and eventually crossed an icy bridge between Europe and North America known as "Beringia." Their path took them down the west coast of North America, although scientists debate about when this actually occurred -- more than 30,000 years ago or more recently. Finally, humans forged into South America and spread east into what is currently the United States and Canada .For the human journey to really get into its stride, our species had to leave the warm embrace of mother Africa. Researchers identify the Bab-el-Mandeb Strait on the Red Sea as the most likely departure point .This narrow stretch of water between the Horn of Africa and the Arabian Peninsula offered the shortest route to new continents. The strait would actually have been even less of a stretch than it is today (12 miles), because when Homo sapiens made the crossing some 60,000 to 70,000 years ago, sea levels were 230 feet lower due to the onset of ice age conditions that locked water up in vast polar ice caps. Given some kind of raft, and perhaps a few islands to hop between, such a crossing isn’t difficult to imagine. Archaeological evidence reveals that modern humans had spread into Southeast Asia from Africa by about 60,000 years ago, Genetic evidence points to Europeans originating from a second migration wave from Africa that took a circuitous path via the Middle East into the steppes of Central Asia before swinging west. and that they were in Australia by about 50,000 years ago. The earliest known evidence of human occupation in Australia is a rock shelter in the Northern Territory that is about 55,000 years old, while the oldest human fossils ever discovered in Australia are about 10,000 years younger. Spencer Wells, a geneticist has speculated that the first Australians landed in northern Australia and Papua New Guinea then part of the same landmass and gradually moved inland by following the river systems of Queensland and southern Australia .The Horn of Africa also offers clues to how our species might have spread swiftly along the coasts of Arabia, India, Southeast Asia, and all the way to Australia. Sites with garbage dumps filled with clam and oyster shells reveal that local inhabitants were familiar with coastal living and exploiting the sea long before any Red Sea crossing. They must have improved their seafaring skills on the way, because getting from Asia to the continental landmass of which Australia was then a part would have meant navigating across a series of straits. Australia shared its prehistoric continent with present-day New Guinea. Reaching Australia would have presented significant challenges for ancient humans. An ocean has always separated Asia and Oceania, and travel between the two continents would have required humans to navigate dozens of miles of open water. Whether humans colonized Australia intentionally or by accident after  being blown there by monsoon winds. Another mystery is what kind of water vessels early humans used to reach Australia. None of the boats used by Aboriginal people in ancient times are suitable for major voyages, and some have suggested early humans reached the continent on rafts made of bamboo, a material common in Asia. However ,small groups left Central Asia for Europe. Cold temperatures kept them there. Cut off from other groups, these migrants became paler and shorter than their African ancestors. From there, around 20,000 years ago, another small group of Central Asians moved farther north, into Siberia and the Arctic Circle. To minimize physical exposure to the extreme cold they developed, over many generations, stout trunks, stubby fingers, and short arms and legs. Finally, around 15,000 years ago, as another Ice Age began to wane, one small clan of Arctic dwellers followed the reindeer herd over the Bering Strait land bridge into North America. The ocean crossing from Asia to Australia is one of humanity’s great early achievements, The earliest people to colonize the Eurasian landmass likely did so across the Bab-al-Mandab Strait separating present-day Yemen from Djibouti. These early beachcombers expanded rapidly along the coast to India, and reached Southeast Asia and Australia by 50,000 years ago. The first great foray of our species beyond Africa had led us all the way across the globe. Slightly later, a little after 50,000 years ago, a second group appears to have set out on an inland trek, leaving behind the certainties of life in the tropics to head out into the Middle East and southern Central Asia. From these base camps, they were poised to colonize the northern latitudes of Asia, Europe, and beyond. But the route early modern humans took while traveling from Africa to Australia still mysterious. It was previously thought that after leaving Africa, humans stayed close to the coasts, with some of them traveling southward until they reached Indonesia and Australia. But some scientists reported the discovery of human skull fragments in a limestone cave in northern Laos that date back to between 46,000 and 63,000 years ago. The finding was surprising, because it indicated early humans roamed far and wide across Asia after leaving Africa, venturing north and northeast across rough mountainous terrain into Laos and perhaps even China, Vietnam, and Thailand. From Central Asia, a small group migrated towards the northeast, following reindeer. These were the Chukchi people, a few of whom still live a nomadic lifestyle today. An even smaller group, estimated at no more than 20 Chukchis, crossed what is now the Bering Sea approximately 13,000 years ago during the last glacial period, and migrated into North America. They are the ancestors of Native Americans, and 800 years later, they had reached as far as South America. Conclusion Eventually, humans moved across nearly all of the earth’s landscapes, including rainforests, deserts, tundra, ice, oceans, and mountains searching for food, water, adaptable environment and a suitable climate to cultivate and plant the earth .early human wanted to live a better life away of drought , harsh desert and the miserable  life that they were living. they ventured in order to get a secure life by crossing all the earth's landscapes they would be able to adapted to the new environment and climate. Scholars speculate that their upright stance and large brains assisted humans in developing the means and the strategies to move over long distances. These same features enabled humans to overcome environmental and physical barriers in a variety of landscapes, and to adapt successfully to the social, political, and ecological realities of their new homes.

Biography Stanyon R, Sazzini M and Luiselli Donata.(2009),Timing the first human migration into eastern Asia,Journal of Biology. Steve Olson.(2002), Mapping Human History: Discovering the Past through Our Genes (Boston: .Houghton Mifflin.

Stephen Castles and Mark J. Miller.(2003),The age of migration

Klien, R.G.(2000) Evol. Anthropol.9,7-36 Journey of Man: A Genetic Odyssey ,By Spencer Wells