Paleolithic -- first part of the Stone Age

Paleolithic

Prehistoric period, first part of the Stone Age

The Paleolithic or Palaeolithic or Palæolithic, also called the Old Stone Age, is a period in human prehistory distinguished by the original development of stone tools that covers c. 99% of the time period of human technological prehistory. It extends from the earliest known use of stone tools by hominins c. 3.3 million years ago, to the end of  the Pleistocene c. 11,650 cal BP.

Hunting a glyptodon. Glyptodons were hunted to extinction within two millennia after humans' arrival in South America.

Cave of Altamira and Paleolithic Cave Art of Northern Spain

The Paleolithic Age in Europe preceded the Mesolithic Age, although the date of the transition varies geographically by several thousand years. During the Paleolithic Age, hominins grouped together in small societies such as bands and subsisted by gathering plants, fishing, and hunting or scavenging wild animals. The Paleolithic Age is characterized by the use of knapped stone tools, although at the time humans also used wood and bone tools. Other organic commodities were adapted for use as tools, including leather and vegetable fibers; however, due to rapid decomposition, these have not survived to any great degree.

About 50,000 years ago a marked increase in the diversity of artifacts occurred. In Africa, bone artifacts and the first art appear in the archaeological record. The first evidence of human fishing is also noted, from artifacts in places such as Blombos cave in South Africa. Archaeologists classify artifacts of the last 50,000 years into many different categories, such as projectile points, engraving tools, knife blades, and drilling and piercing tools.

• Humankind gradually evolved from early members of the genus Homo—such as Homo habilis, who used simple stone tools—into anatomically modern humans as well as behaviourally modern humans by the Upper Paleolithic. During the end of the Paleolithic Age, specifically the Middle or Upper Paleolithic Age, humans began to produce the earliest works of art and to engage in religious or spiritual behavior such as burial and ritual.Conditions during the Paleolithic Age went through a set of glacial and interglacial periods in which the climate periodically fluctuated between warm and cool temperatures. Archaeological and genetic data suggest that the source populations of Paleolithic humans survived in sparsely-wooded areas and dispersed through areas of high primary productivity while avoiding dense forest-cover.

By c. 50,000 – c. 40,000 BP, the first humans set foot in Australia. By c. 45,000 BP, humans lived at 61°N latitude in Europe. By c. 30,000 BP, Japan was reached, and by c. 27,000 BP humans were present in Siberia, above the Arctic Circle. At the end of the Upper Paleolithic Age a group of humans crossed Beringia and quickly expanded throughout the Americas.

Etymology

The term "Palaeolithic" was coined by archaeologist John Lubbock in 1865. It derives from Greek: παλαιός, palaios, "old"; and λίθος, lithos, "stone", meaning "old age of the stone" or "Old Stone Age".

Paleogeography and climate

This skull, of early Homo neanderthalensis, Miguelón from the Lower Paleolithic dated to 430,000 bp.

Temperature rise marking the end of Paleolithic, as derived from ice core data.

The Paleolithic coincides almost exactly with the Pleistocene epoch of geologic time, which lasted from 2.6 million years ago to about 12,000 years ago. This epoch experienced important geographic and climatic changes that affected human societies.

During the preceding Pliocene, continents had continued to drift from possibly as far as 250 km (160 mi) from their present locations to positions only 70 km (43 mi) from their current location. South America became linked to North America through the Isthmus of Panama, bringing a nearly complete end to South America's distinctive marsupial fauna. The formation of the isthmus had major consequences on global temperatures, because warm equatorial ocean currents were cut off, and the cold Arctic and Antarctic waters lowered temperatures in the now-isolated Atlantic Ocean.

Most of Central America formed during the Pliocene to connect the continents of North and South America, allowing fauna from these continents to leave their native habitats and colonize new areas. Africa's collision with Asia created the Mediterranean, cutting off the remnants of the Tethys Ocean. During the Pleistocene, the modern continents were essentially at their present positions; the tectonic plates on which they sit have probably moved at most 100 km (62 mi) from each other since the beginning of the period.

Climates during the Pliocene became cooler and drier, and seasonal, similar to modern climates. Ice sheets grew on Antarctica. The formation of an Arctic ice cap around 3 million years ago is signaled by an abrupt shift in oxygen isotope ratios and ice-rafted cobbles in the North Atlantic and North Pacific Ocean beds. Mid-latitude glaciation probably began before the end of the epoch. The global cooling that occurred during the Pliocene may have spurred on the disappearance of forests and the spread of grasslands and savannas. The Pleistocene climate was characterized by repeated glacial cycles during which continental glaciers pushed to the 40th parallel in some places. Four major glacial events have been identified, as well as many minor intervening events. A major event is a general glacial excursion, termed a "glacial". Glacials are separated by "interglacials". During a glacial, the glacier experiences minor advances and retreats. The minor excursion is a "stadial"; times between stadials are "interstadials". Each glacial advance tied up huge volumes of water in continental ice sheets 1,500–3,000 m (4,900–9,800 ft) deep, resulting in temporary sea level drops of 100 m (330 ft) or more over the entire surface of the Earth. During interglacial times, such as at present, drowned coastlines were common, mitigated by isostatic or other emergent motion of some regions.

Many great mammals such as woolly mammoths, woolly rhinoceroses, and cave lions inhabited the mammoth steppe during the Pleistocene.

The effects of glaciation were global. Antarctica was ice-bound throughout the Pleistocene and the preceding Pliocene. The Andes were covered in the south by the Patagonian ice cap. There were glaciers in New Zealand and Tasmania. The now decaying glaciers of Mount Kenya, Mount Kilimanjaro, and the Ruwenzori Range in east and central Africa were larger. Glaciers existed in the mountains of Ethiopia and to the west in the Atlas mountains. In the northern hemisphere, many glaciers fused into one. The Cordilleran Ice Sheet covered the North American northwest; the Laurentide covered the east. The Fenno-Scandian ice sheet covered northern Europe, including Great Britain; the Alpine ice sheet covered the Alps. Scattered domes stretched across Siberia and the Arctic shelf. The northern seas were frozen. During the late Upper Paleolithic (Latest Pleistocene) c. 18,000 BP, the Beringia land bridge between Asia and North America was blocked by ice, which may have prevented early Paleo-Indians such as the Clovis culture from directly crossing Beringia to reach the Americas.

According to Mark Lynas (through collected data), the Pleistocene's overall climate could be characterized as a continuous El Niño with trade winds in the south Pacific weakening or heading east, warm air rising near Peru, warm water spreading from the west Pacific and the Indian Ocean to the east Pacific, and other El Niño markers.

The Paleolithic is often held to finish at the end of the ice age (the end of the Pleistocene epoch), and Earth's climate became warmer. This may have caused or contributed to the extinction of the Pleistocene megafauna, although it is also possible that the late Pleistocene extinctions were (at least in part) caused by other factors such as disease and overhunting by humans. New research suggests that the extinction of the woolly mammoth may have been caused by the combined effect of climatic change and human hunting. Scientists suggest that climate change during the end of the Pleistocene caused the mammoths' habitat to shrink in size, resulting in a drop in population. The small populations were then hunted out by Paleolithic humans. The global warming that occurred during the end of the Pleistocene and the beginning of the Holocene may have made it easier for humans to reach mammoth habitats that were previously frozen and inaccessible. Small populations of woolly mammoths survived on isolated Arctic islands, Saint Paul Island and Wrangel Island, until c. 3700 BP and c. 1700 BP respectively. The Wrangel Island population became extinct around the same time the island was settled by prehistoric humans. There is no evidence of prehistoric human presence on Saint Paul island (though early human settlements dating as far back as 6500 BP were found on the nearby Aleutian Islands).