Quiz 9: The Rise of Modern Humans
Depending on the researcher, there can be from one to eight various species in the genus Homo , identified as existing during the Pleistocene period (from 1.8 million years ago). It should be noted however, that between 0.5 and 0.2 million years ago, fossils of the genus Homo is being called Homo heidelbergesis because many researchers see this species as representing most of the archaic humans (including the Neanderthals). Other researchers do not agree with the H. heidelbergesis hypothesis and speculate that it is the archaic Homo sapiens , because it appears to be transitioning into a sapiens -like morphology with a larger cranial capacity and subsequent larger brain size. Still, there are other researchers who claim that older fossils of the H. antecessor are ancestral to modern humans and the H. heidelbergensis , which then gave rise to the Neanderthals but not to modern H. sapiens. Despite the contention between which of the species of the genus Homo represent archaic humans, classification arguments has to do with individual researchers' perspectives on the pattern of evolution leading to modern humans. In other words, classification questions depend on whether the Neanderthals are a separate species or another archaic human form in the modern human lineage. Each researcher will have their own view of this issue and therefore, that is the reason why different researchers looks at the same fossils and call them different things. Researchers and their disagreement with the fossils of archaic humans within the genus Homo further demonstrate that the concept of species and evolutionary change is highly debatable and controversial. This type of disagreement shows that the concept of species is not clear-cut and fossil analysis of morphology in archaic humans does not necessarily show a clear evolutionary change in between species. For example, it would be ideal for H. heidelbergensis to precede H. sapiens in the order of morphological development so that researchers can indicate a clear evolutionary change, but this is not the case. Researchers are showing discrepancies in the lineage of archaic humans and the evolutionary changes of archaic humans are up for further debate.
Researchers agree that there are modern Homo sapiens fossils present in Southeast Asia dating from at least 50,000 years ago. Evidence of both H. erectus and H. floresiensis fossils were discovered in the region dating to 30,000 to 27,000 years ago and about 12,000 years ago, respectively. However, it is also agreed by researchers that there are no currently accepted archaic human fossils from Southeast Asia that predate the discovery of modern human fossils. The presence of fossils such as H. erectus in the region but no archaic humans can be due to the fact that H. erectus and H. floresiensis lingered as outliers in human evolution in that region until the appearance of modern humans. The discovery of modern human fossils on the continent of Australia that was dated to approximately 60,000 years ago is an interesting phenomenon because during that time, Australia was separated 62 miles from the nearest land masses by a span of ocean. Experts can only speculate as to the origins of these fossils and theorize that the early modern humans must have built rafts or boats to travel the oceans from one land mass to another (such as Australia), although there is no archeological evidence to support this theory. It is more than likely that the fossils of early modern humans discovered in Australia originated from the islands of Timor and Flores, just north of Australia. It is also speculative that there are no similar fossils just before 60,000 years ago in the Indonesian Islands because archaic humans originated from another region and settled in the regions of Australia and the Indonesian Islands as modern humans.
From archeological evidence, it is apparent that later archaic humans, such as the Neanderthals, not only buried their dead (in regions of western Eurasia and the Mediterranean), but placed the deceased in specific positions or adorned the burial sites with "grave goods" such as tools or flowers. It is exciting to anthropologists to find evidence of personal adornment in these sites because it demonstrates that archaic humans are aware of the concept of death and were cognizant in belief systems incorporating an afterlife. Researchers concluded that by at least 50,000 years ago, art (or nonfunctional symbolism) has been associated with fossil sites in Africa and Australia and almost everywhere else modern humans existed. Early art by modern humans ranges from simple etchings on cave walls to marks on tool handles. Such demonstration of expression leads researchers to speculate a cultural development in relation to a change in human behavior. Art depicted by modern humans did not serve a clear function, other than holding a cultural significance to the individuals or the groups who produced them. The time lag between modern human morphology and the appearance of art (or complex symbolic behavior) may not have an evolutionary undertone associated with it. The appearance of art, or complex symbolic behavior, may have been in the changing structure of the brain in relation to culture, where modern humans used such symbols in an attempt to understand its place in the world. These symbols may have been related to an emergence in belief systems, such as beliefs in hunting and foraging, changes in seasons and past events. In other words, the time lag may be due to a development in human morphology leading to culture and social behavior, thereby leading to the development of complex symbolic behavior.