Origins cont'd

Non-Genetic Methods of Analysis

Through careful review of the non-genetic evidence that exists in the forms of the fossil and cultural records, a common theme can be found regarding human origins: man originated in Africa. All of the validated fossil evidence supports this in terms of ages, ranges, and overlaps, and the cultural record bears similar witness, with evidence present in the forms of tool use, civilization and agriculture, and language.

The fossil record (http://www.talkorigins.org, Kurland)

The earliest known human ancestor (published) is Ardipthidus ramidus, about whom little is known other than an approximate date of 4.4 mya (million years ago). Following ramidus is Australopithecus anamensis, who existed in what is now South Africa between 4.2 and 3.9 mya. These two species are found solely in East Africa, and appear to be one of the first direct ancestors of anatomically modern humans. Following these comes a species with a relatively long distribution through time, A. (for Australopithecus) afarensis, dating between 3.9 and 3.0 mya, although dates could extend well past either of these dates (and most likely do). A. africanus, the species to which the famed "Lucy" belongs, is next, and lived from 3 mya to 2 mya, again in Africa, primarily in the South and East.

During the time when A. afarensis existed it appears that the hominid lineage split into two distinct branches, the graciles (who became modern man) and the robust (who became extinct). The first robust member was A. aethiecpus, characterized primarily by a single skull found by Dr. Alan Walker. Aethiecpus existed from approximately 2.6 to 2.3 mya. From 2 to 1.5 mya ago A. robustus, the second in the line of robust forms, flourished. The final robust form was A. boseii, which lived between 2.1 and 1.1 mya. At this point the robust line ceased to exist without leaving any direct descendants. They are considered an off-branch of the evolutionary chain, not directly related to Homo sapiens.

The graciles began with Homo habilis, a controversial species that roamed the earth between 2.4 and 1.5 mya. H. habilis is very controversial in that it exemplifies the differences between two groups or anthropologists, the "lumpers" and the "splitters." The lumpers who do not support H. habilis fear that the splitters have mistakenly mixed H. erectus and A. afarensis fossils into a new species. The splitters who do not support H. habilis fear that the lumpers have taken fossils from a variety of species as yet not fully characterized and improperly grouped them together.

Regardless of whether or not H. habilis was a true single species, it was soon followed by H. erectus. H. erectus was a powerful creature first appearing almost 2 mya and living perhaps until 50 000 years ago1, although a large population crash appears to have occurred about 300 kya which may have eliminated the entire species. H. erectus is the first species that will be discussed in detail as it is at this point that the two primary theories begin to differ.

H. erectus, like all of its predecessors, was originally an African species. As far as is known, all other hominid species up until H. erectus originated in Africa and never left Africa. H. erectus, however, did leave Africa. Fossil evidence shows that H. erectus was in Java by 1.8 mya and in Spain by 800 kya. During this time (and afterwards) a residual population remained in and populated additional areas of Africa. Eventually much of Europe was colonized, as was some of Indian and Southern and Southeastern Asia. H. erectus did not reach Australia or Polynesia, nor did their range extend into Northern Asia or the Americas.

Approximately 500 kya H. erectus began to differentiate and possibly speciate. A new fossil type, characterized as archaic H. sapiens, began to appear. This fossil type is highly variable, with individuals beginning to show markedly different forms from H. erectus. All specimens seem to exhibit some mix of erectus and AMH traits, although the exact mix of these characteristics is extremely various. These transitory forms appear scattered throughout the world, and are positive evidence for MRE in that they show individual H. erectus populations changing towards more modern morphology. These archaic sapiens persisted until at least 200 kya and most likely slightly longer.

Approximately 250 kya a final offbranch of the hominoid evolutionary tree appeared in Europe. This new species, H. neanderthalensis, lived in Europe until just 30 kya. At that time they were definitely replaced by AMH without admixture, and recent studies of mtDNA indicate conclusively that they were not direct descendents of modern man. This argues against MRE, as many consider Neanderthals to be only a specific type of archaic species present in Europe, which means that the other archaic forms are every bit as much a separate species as H. neanderthalensis is. This weakens the evidence against MRE because begs a response as to why the other archaics should be considered leading towards AMH if N. neanderthalensis clearly was not.

From the fossil record then, it can be concluded that some populations of H. erectus, H. neanderthalensis, archaic H. sapiens, and AMH all existed concurrently with at least one other species. This indicates that MRE is not at all probable, as two main fossil traces of MRE are missing. First, there is no continuity of form leading directly from H. erectus to H. sapiens sapiens (anatomically modern humans, versus H. sapiens, which can include the archaic forms), with no consistent intermediate types found. And secondly all four of the most recent hominid types appear to have existed during a time range with at least one other, something MRE predicts against.

The cultural record

The cultural record also seems to indicate an expansion from Africa, although the picture it paints does not correspond with a strict Out of Africa hypothesis, a problem that will be dealt with at the end of this essay. The cultural records discussed in this essay consist of the tool record and the cultural ecology record. The linguistic record is not discussed, as it relies on formalized oral communication, a characteristic whose capacity for is unknown in H. erectus, H. neanderthalensis, and the archaic species.

Tools The first instance of lithic tool use is referred to as the Oldowan industry. This industry had incredible staying power, being the only industry seen from 2.6 to 1.6 mya. It should be noted that these dates correspond very closely with that of the existence of H. habilis. The next tool industry was the Acheulian, which begins shortly after H. erectus evolves. It is possible that these tools enabled erectus to adapt well enough to leave Africa, something that erectus had done by 1.8 mya. These tools were used almost until the collapse of the erectus population. Beginning 500 kya Mousterian tools began to appear, and these were made by archaic populations, including the Neanderthals. As opposed to the previous industries, which consisted of only one type, the Mousterian industry produced over forty types. The number of these tools made appears to increase until about 100 kya, at which time they completely disappear. Not surprisingly, perhaps, this is the time when AMH is suspected to have begun reaching many archaic populations, and indeed a new industry is seen, called the Upper Paleolithic. This industry first appears in Africa 200 kya, and there are more types and more innovations found in this industry than in every industry of the last 2.5 million years combined. (Matson Museum)

This record of tools is important to evaluating human expansion based on one assumption: tool use is characteristic of the species using it. In other words, H. habilis invented Oldowan tools, and H. erectus, with increased mental facilities, was able to invent Acheulian, then H. neanderthalensis and other archaics invented Mousterian, and finally AMH founded Upper Paleolithic tools. This is admittably a questionable assumption as (for example) Neanderthals were found associated with AMH tools. However, this is, in many minds, simply an occurrence of cross-culturation, a belief this paper subscribes to. Assuming this hypothesis to be true, the tool record supports the fossil record in indicating a single African origin for H. sapiens sapiens.

Cultural Ecology The cultural ecological record does not extend far enough into the past to allow valid analysis of the earliest human origins. It does, however, provide a means to analyze migratory patterns of different individuals after AMH left Africa. Space does not permit a long analysis, but suffice to say that this process yields a wealth of information beginning approximately 20 000 years ago, when AMH were the sole hominids left. Cultural ecology provides clues as to the first appearance of domestic crops (einkorn wheat perhaps, 12000 to 10000 years ago in the Middle East) (Science Times, article not found), the first inhabitance of the Americas (100 species of animals abruptly became extinct at the exact time hunter gatherers are believed to have entered the New World 20 000 years ago) (Snow), and similarly the first expansion to other areas (such as Australia, Russia, and so on). These results will be discussed in more detail in the conclusion of this paper.

The primary concept that should be apparent from both the fossil and the cultural evidence is that innovation originates in Africa. The first known ancestors existed solely there, the first known lithic tools were produced there, the later species in the line began in Africa and expanded outward from there, and there is definite fossil evidence for this. There are older cultural establishments near Africa than any other part of the world. Also, the first civilizations appear near North Africa and the dates of settlement generally increasing with distance from Africa, as seen in Australia and the New World. Over and over again an Out of Africa pattern is repeated in cultural, fossil, and tool records.

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