The Site Where Humans And Neanderthals Met And Mixed - IELTS Reading Answers & Explanations

You should spend about 20 minutes on Questions 28–40, which are based on Reading Passage 3 on the following pages.

Reading Passage 3

A Among prehistoric archeologists, Ksar Aqil has an almost mythical status, but the site is little known outside professional circles. The migration of modern humans out of Africa and the Near East's position as a bridge between continents and cultures, as well as nearly a century of scientific research, are all woven into the story of Ksar Aqil. Current perspectives on human evolution and mankind's colonization of the globe are based upon fossil evidence, as well as excavated artifacts and biogenetic data. These lines of inquiry indicate a relatively recent evolution of modern humans, Homo sapiens sapiens, in Africa about 200,000 years ago.

B The latest, and arguably most powerful, analytical tool available to those investigating human origins comes from molecular biology. Geneticists have found that examination of the DNA from tiny structures inside the cell, called mitochondria, provided a means to measure human biogenetic relationships on a time scale spanning hundreds of thousands of years. Mitochondria, also known as the powerhouse of the cell because they generate chemical energy, possess their own genome, and mitochondrial DNA (mtDNA) is inherited exclusively from the mother. Dramatic results released in 1987 by researchers at the University of California at Berkley indicated that all mtDNA present in people today stems from a single female who lived about 200,000 years ago in Africa. This woman was called "Mitochondrial Eve," the genetic mother of all of earth's present-day population.

C Tens of thousands of years before Beirut became a meeting place of East and West, the Levantine coastal strip and the Arabian Peninsula to the south were corridors through which our common ancestors moved out of Africa and into Asia, Europe, Australia and, lastly, the Americas. The region also has the distinction of being a place where Neanderthals (Homo sapiens neanderthalensis) and our immediate ancestors co-existed and indeed interbred. Although the evolutionary split between Neanderthals and the ancestors of modern humans occurred sometime between 440,000 and 270,000 years ago, according to research, a little Neanderthal DNA, between one and four per cent, exists in all peoples alive today, except for those in Africa. It is probable that our Neanderthal heritage resulted from interbreeding that happened in the Near East sometime between 80,000 and 45,000 years ago.

D According to proponents of the "out of Africa" theory, the exodus of anatomically modern humans probably occurred in waves. One early migration into the Near East occurred prior to 130,000 years ago, and an examination of a modern map of the Horn of Africa and adjacent parts of Arabia shows there are two obvious routes this migration could have taken. One involves crossing from northern Egypt into the Sinai Peninsula, the other crosses the Bab el-Mandab strait to reach modern-day Yemen, perhaps by watercraft. It is likely that both these routes were taken at different times, as they were navigable, presented no significant hazards and were frequented by the animals our early ancestors tracked and hunted. Given the geographic position of the Near East as a bridge between Europe and Asia, this region formed the trunk through which our family tree branched out from its African roots, both geographically and genetically. When modern humans entered the area over 130,000 years ago, the Neanderthals were in residence, and it seems they curtailed the extent of the newcomers' settlement for a while. When another wave of modern humans began migrating from Africa about 50,000 years ago, perhaps due to population pressure on resources and territory, our ancestors ultimately became the sole inhabitants of places like Ksar Aqil.

E If this contest had been based on physical strength alone, the Neanderthals would have won hands down. Modern humans, however, had developed cognitive, physical and cultural abilities that provided an advantage, ultimately leading to the Neanderthals being relegated to geographically marginalized refugees. Neanderthals differed from modern humans in a number of ways, perhaps most noticeably in their skull anatomy, which featured a sloped forehead, a large projection at the back of the skull called an occipital bun, pronounced eyebrow ridges, and no chin. Physically robust and more powerfully built than our ancestors, their massive but relatively short stature was more efficient in cold climates like Europe's. In common with modern humans, they possessed a gene essential for language development, and some paleoanthropologists believe they were capable of complex speech patterns. The Neanderthals apparently were not suited to activities like long-distance running. The energy cost of locomotion was apparently 32 per cent higher in Neanderthals, resulting in a daily dietary requirement between 100 and 350 calories greater than that of modern humans living in similar environmental settings. Our ancestors may, therefore, have had a competitive edge simply by being more fuel-efficient.

F What exactly happened to the Neanderthals no one knows. Modern peoples migrating into Southwest Asia and on to Europe may have displaced them. Undoubtedly, contact led to a variety of interactions, some clearly resulting in opportunities for interbreeding, others involving physical conflict and competition for resources. The Neanderthals' demise may also have been linked to rapid climatic swings between 50,000 and 30,000 years ago, which created further pressure on their already divided and isolated populations.