Weapons

Humans—the genus Homo—may have descended from australopithecine ancestors, while the genus Ardipithecus is a possible ancestor of the australopithecines.

Australopithecine is the general term for any species in the related genera of Australopithecus and Paranthropus.

They are bipedal and dentally similar to humans, but with a brain size not much larger than that of modern apes.

It appears that the Australopithecus genus evolved in eastern Africa around four million years ago before spreading throughout the continent and eventually becoming extinct two million years ago.

During this time period several australopith species emerges, including Australopithecus afarensis, A. africanus, A. anamensis, A. bahrelghazali, A. garhi and A. sediba.

Opinions differ as to whether the species aethiopicus, boisei, and robustus should be included within the genus Australopithecus, and there is no current consensus as to whether they should be placed in the distinct group of hominids now called the "robust australopiths” or, Paranthropus (Greek para, "beside"; Greek anthropos, “human”).

The fossil record seems to indicate that Australopithecus is the common ancestor of Paranthropus, and most likely the genus Homo, which includes modern humans.

Though the intelligence of these early hominids is likely no more sophisticated than modern apes, the bipedal stature is the key evidence that distinguishes the group from previous primates, who were quadrupeds.

Most species of Australopithecus are no more adept at tool use than modern nonhuman primates, yet modern African apes, chimpanzees, and most recently gorillas, have been known to use crack open nuts with stones and use long sticks to dig for termites in mounds, and chimpanzees have been observed using spears (not thrown) for hunting.

However, some have argued that A. garhi used stone tools due to a loose association of this species and butchered animal remains.

Trace element studies of the strontium/calcium ratios in robust australopith fossils  in 1992 suggested the possibility of animal consumption, as they did in 1994 using stable carbon isotopic analysis.

The so-called Levallois technique of stone working, in which a large thin flake is struck from a prepared core and used as a blank for making more specialized tools such as knives and scrapers, is invented during this period.

A striking platform is formed at one end, then the core's edges are trimmed by flaking off pieces around the outline of the intended flake.

This creates a domed shape on the side of the core, known as a tortoise core as the various scars and rounded form are reminiscent of a tortoise's shell.

When the striking platform is finally hit, a flake separates from the core with a distinctive plano-convex profile and with all of its edges sharpened by the earlier trimming work.

This method provides much greater control over the size and shape of the final flake, which is employed as a scraper or knife; the technique can also be adapted to produce projectile points known as Levallois points.

The technique is first found in the Lower Paleolithic but is most commonly associated with the Neanderthal Mousterian industries of the Middle Paleolithic.

In the Levant, Levallois methods are also in use in the Upper Paleolithic and later.

The distinctive forms of the flakes were originally thought to indicate a wide-ranging Levallois culture but the wide geographical and temporal spread of the technique has rendered this interpretation obsolete.

Homo erectus (a species of human best known from finely made handaxes and other butchery tools found at locations like Isimila and …

…Kalambo Falls in eastern Africa, sites dating to more than two hundred thousand years ago) has proven to be a more effective forager than its predecessor, with the ability to kill even large animals with fire-hardened wooden spears.

According to conventional theory, these archaic humans, who settled in all parts of Africa, evolved gradually toward modern forms, their skulls becoming more rounded, skeletons less robust, and molar teeth smaller.

H. ergaster is thought to be the first hominin to vocalize.

As H. heidelbergensis developed, more sophisticated culture proceeded from this point.

Anatomically modern humans, Homo sapiens sapiens, evidently evolve in tropical Africa between 150,000 and 100,000 BCE.

Archaeological evidence reveals signs of technological change throughout eastern and southern Africa before 130,000 BCE, as the heavier toolkits of earlier times gave way to lighter, more specialized toolkits, which included sharp spearpoints that can be mounted on wooden shafts.

The beginning of the last Ice Age is conventionally dated at about 120,000 BCE.

The Eemian, an interglacial period which begins about one hundred and thirty thousand years ago and ends about one hundred and fourteen thousand years ago, is the second-to-latest interglacial period of the current Ice Age, the most recent being the Holocene which extends to the present day.

The prevailing Eemian climate is believed to have been about as stable as that of the Holocene.

Changes in the earth's orbital parameters from today (greater obliquity and eccentricity, and perihelion), known as the Milankovitch cycle, probably lead to greater seasonal temperature variations in the Northern Hemisphere, although global annual mean temperatures are probably similar to those of the Holocene.

The warmest peak of the Eemian is around one hundred and twenty-five thousand years ago, when forests reach as far north as North Cape (which is now tundra) in northern Norway well above the Arctic Circle.

Hardwood trees like hazel and oak grow as far north as Oulu, Finland.

At the peak of the Eemian, the northern hemisphere winters are generally warmer and wetter than now, though some areas are actually slightly cooler than today.

The hippopotamus is distributed as far north as the rivers Rhine and Thames.

Trees grow as far north as southern Baffin Island in the Canadian Arctic Archipelago instead of only as far north as Kuujjuaq in northern Quebec, and the prairie-forest boundary in the Great Plains of the United States lies further west—near Lubbock, Texas, instead of near Dallas, Texas, where the boundary now exists.

Sea level at peak is probably four to six meters (thirteen to twenty feet) higher than today (references in Overpeck et al., 2006), with much of this extra water coming from Greenland but some likely to have come from Antarctica.

Global mean sea surface temperatures are thought to have been higher than in the Holocene, but not by enough to explain the rise in sea level through thermal expansion alone, and so melting of polar ice caps must also have occurred.

Because of the sea level drop since the Eemian, exposed fossil coral reefs are common in the tropics, especially in the Caribbean and along the Red Sea coastlines.

These reefs often contain internal erosion surfaces showing significant sea level instability during the Eemian.

A 2007 study found evidence that the Greenland ice core site Dye 3 was glaciated during the Eemian, which implies that Greenland could have contributed at most two meters (6.6 feet) to sea level rise.

Scandinavia was an island due to the inundation of vast areas of northern Europe and the West Siberian Plain.

Given that the shorelines of the islands of the present are at this time several feet higher, humans of this epoch must have used boats: the large island of Crete in the Aegean basin is settled as early as 128,000 BCE, during the Middle Paleolithic age.

The period closes as temperatures steadily fall to conditions cooler and drier than the present, with four hundred and sixty-eight-year long aridity pulse in central Europe, and by one hundred and fourteen thousand years before the present, a glacial era has returned.

The rapid expansion of anatomically modern humans out of Africa, beginning around 60,000 years ago, appears to coincide with the development of new stone tool-making techniques.

These innovations, which define the Upper Paleolithic period, distinguish the stone tool culture of Homo sapiens sapiens from the previously similar technologies of Neanderthals and other archaic human groups.

Key advancements include:

• The production of long, narrow flake tools, known as blades, which could be fashioned into a variety of specialized tools,
• The emergence of bone and ivory artifacts, and
• The eventual development of clothing, often sewn together and adorned with beads.

These technological advancements likely played a crucial role in the success and adaptability of early modern humans as they spread across new environments.

Modern humans begin to move out of the Horn of Africa, some traveling south, others moving east into Arabia along the Indian Ocean’s 'Coastal Express' route, eventually to arrive in Australia; others penetrate northeast into West Asia, a route presumably rendered impassable in former times by tough, strong, spear-wielding Neanderthals.

The bow and arrow, which allows hunters to attack animals from a secure distance, is, according to some indirect evidence, invented during this period.

Bone arrow points dating to sixty-one thousand years ago have been found at Sibudu Cave in South Africa.

The development of stone tools appears to have progressed in gradual steps until around 50,000 to 40,000 years ago.

Each successive Homo species—from H. habilis to H. ergaster to H. neanderthalensis—began at a higher technological level than its predecessor. However, once a phase began, further innovation remained slow, reflecting a culturally conservative approach to tool-making.

Around 50,000 BP, however, modern human culture began to evolve at a significantly faster pace. While Neanderthal populations typically displayed little variation in their tool-making techniques, the Cro-Magnon immigrants introduced increasingly refined and specialized flint tools, such as knives, blades, and skimmers.

Additionally, Cro-Magnons expanded beyond stone, pioneering the use of bone tools, marking a major advancement in prehistoric technology.