Palaeoarchaeology

Palaeoarchaeology (or paleoarcheology) is the archaeology of deep time. Paleoarchaeologists' studies focus on hominid fossils ranging from 15,000,000 to 10,000 years ago, and emphasize human evolution and how humans have adapted to the environment in the past few million years.

Interest in the field of study began in the late 1850s and early 1860s, with a shift in interest caused by the discoveries made by Boucher de Perthes, after Joseph Prestwich, Hugh Falconer, and John Evans had visited Boucher de Perthes's site in the Somme valley themselves. Two such archaeologists who had been attracted to join archaeological societies by palaeoarchaeology were Augustus Pitt Rivers and Edward Burnett Tylor. Evans, Pitt Rivers, and John Lubbock all promoted interest in the field, each an enthusiast and each quickly rising to positions of authority and influence within archaeological circles. In 1868, for example, they together organized, in conjunction with the annual general meeting in Norwich of the British Association for the Advancement of Science, the Third International Congress of Prehistoric Archaeology.

The majority of paleoarchaeology sites are found in Southern and Eastern Africa. Some of the most productive sites have been those of Hadar, Sterkfontein, Kanapoi, and Olduvai Gorge.

The fact that paleoarchaeology deals with such ancient human remains presents some unique difficulties. Often the remains that are found are incomplete. In addition, paleoarchaeologists often deal with remains that lie somewhere between their primate ancestors and modern humans. This can make the analysis of the remains rather difficult. Similar finds can be rare so paleoarchaeologists must rely on the reanalysis of existing fossils.

In an attempt to analyze human evolution, paleoarchaeologists have been engaged in an attempt to find the last common ancestor of all hominids. It is currently believed that the fossil belonging to Orrorin tugenensis may represent the last common ancestor. It is estimated that this fossil is 6.2-5.6 million years ago. Unfortunately, as with many other fossils, O. tugenensis only contains a partial skeleton (femur, teeth, humerus, mandibles, and fingers). This means that it still requires a great deal of analysis. Currently several researchers have suggested that O. tugenensis is indeed a bipedal primate who was ancestral to later hominins.

In addition to the traditional methods of archaeology and physical anthropology, linguistics, paleogenomics, geography and various fields of environmental studies are used to explore the questions in the field.

Further reading

Paving the Way for Modern Humans, and the Possible Future of Humanity Over the course of human history, there have been five major extinctions. The fourth of these extinctions however, is one of the least known, as it is the extinction event that paved the way for the dinosaurs, and later, humans. Dennis Kent and Paul Olsen of Columbia University's Lamant-Doberty Earth Observatory are two of the worlds leading experts in this area. Their theory is that volcanism is the ultimate key in the demise of the dinosaurs. They believe that the Sulfuric ash which would have filled the sky during a major volcanic event, would have chilled the Earth. As this ash would have settled relatively quickly, the greenhouse effect would then be left to play its part; warming the Earth through the gradually increasing abundance of CO2 emissions, of which would have a much longer lifetime in the atmosphere. After the freeze, the CO2 would then gradually warm the Earth, while also polluting the waters through acidification. Kent and Olsen believe that it is this "flipping back and forth between the extremes of hot and cold, quite possibly would be worse than either one alone". however, it is most likely a combination of all these events, including the possible impact of a meteorite {due to significant traces of the element Iridium that was left behind in the fossil record} that resulted in the extinction. Supporting evidence of volcanism is provided within the analysis of Kent and Olsen of existing lava sheets in the northeastern U.S. These Lava sheets were cyclic, separated by approximately 200,000 years, and between these layers, enormous spikes in the levels of CO2 were found. Five to ten times the levels seen today. Paleoarcheology is important within this regard so that we may not only understand the timeline of Earth in better detail, but also so that we may prevent a possible sixth mass extinction of humans. For if the cyclic heating and cooling that was caused by an increase in CO2 is what indeed what resulted in the extinction of the dinosaurs, then measures need to be taken to prevent out own extinction as well.

An Example of Human Origins The evolution of walking upright is one of the main associations to the physiology of the modern-day man. Looking back upon the fossil remains, it is known that about 3-3.4 million years ago there existed two different species that possessed two different modes of motion. One species was the Australopithecus Afarensis, and the other species being an offshoot of the Aridipithecus Ramadis nicknamed "Kadanuumuu," meaning "big man" in the Afar language. This species was found in the Urenco-Mille area in the Afar region of Ethiopia. One of the main structural differences between these two species is in the foot morphology of these early humans. The Australopithecus Afarensis is known to have been fully bipedal, with a foot morphology very similar to that of our own. Aridipithecus Ramadis on the other hand possessed a big toe that was not aligned with the other four toes. This allowed for a grasping function; which would be useful when climbing trees, suggesting that the Kadanuumuu specimen found was not a bipedal species.

Phytoliths Phytoliths stem from a Greek origins, phyto meaning 'Plants', and Lith meaning 'Stone'. Phytoliths are tiny and are less than 50 um large. They can be extracted from different artifacts such as teeth, tools, and pottery. Phytoliths can be used as an alternative source of dating. Phytoliths have been extensively characterized as of 2005 within the International Code for Phytolith Nomenclature (ICPN). The three main descriptive factors include: One, describing either the 2-D or 3-D shape of the phytolith, as well as the given orientation of their form. Two, the texture of the phytolith and/or their respective ornamentation. Three, the Anatomical origin of the species, which should only be noted when clear and beyond a doubt in order to avoid potential confusion in naming the species.