Unlike other hominids, Homo sapiens did not have an archeological proof of origin as well as evolution. For this case, there have been controversies concerning the source of the species that transformed into the modern humans (Human Evolution 15). There are propositions regarding the origin of this species; one of them being the out-of-Africa model. The model supposes that Homo sapiens evolved about 200,000 years ago from Africa because of the discovery of the mitochondrial DNA eve and the chromosomal Adam. The findings involved a female and male ancestor of the human race that had all the DNA traces of all individuals (Human Evolution 17).
Homo sapiens and the Features That Distinguish Them from Homo erectus
There is a conventionally acceptable concept that all hominids that existed beyond the middle Pleistocene era belonged to the Homo sapiens group. Therefore, it means that there are a number species in the line of human evolution. For instance, the earliest forms of Homo sapiens consisted of a group of hominids that had intermediate features between Homo erectus and Homo sapiens (Human Evolution 34). This group of sapiens had a brain size; about 1200cc, which was larger than Homo erectus than but smaller than modern humans. The species referred to, in this case, had different names according to their places of discovery. An example of the hominids called archaic Homo sapiens was the Homo antecessor discovered in Spain, Homo heidelbergensis found in Germany and England, and the broken hill and Bodo in Africa.
Next, there is the Homo neanderthalensis, which occurred between 30,000 and 230,000 years ago (Human Evolution 45). This species of Homo sapiens had a larger brain size than the modern humans, approximately 1450cc. However, the hominid had a lower brain case than the modern humans and had a bulge at the rare side of its skull. The skull of the species also had a receding forehead as well as protuberant jaws and a weak chin. Another feature of the skull of Homo neanderthalensis was the possession of a protuberant mid-facial region, which was an outstanding feature that differentiated the species from the rest of the sapiens.
Another species of the Homo sapiens was the Homo sapiens sapiens. This species appeared for the first time about 120.000 years ago (Bandelt, Vincent & Martin 100). They had an approximate brain size of about 1350 cc. The species has a forehead that rises sharply and has smaller eyebrow ridges or at times missing and also had smaller canines than its ancestors (Human Evolution 45). Homo sapiens sapiens also have a gracile skull and a super-intelligent brain capacity.
Therefore, Homo erectus and Homo neanderthalensis alike have an elongated skull that have broad brow ridges, which is different from that of Homo sapiens. For this case, the Homo sapiens have reduced brow ridges that may at times be absent and a shorter skull. The eyebrow ridges of the neanderthalensis form arches above each eye, which is different with those of Homo erectus. However, Homo neanderthalensis also had a larger brain size than Homo sapiens, but a lower brain case than the Homo sapiens and had a bulge at the rare side of its skull (Human Evolution 23).
The Spread of Homo sapiens and the Theories for the Disappearance of Other Species
There are a number of models suggested by scientists and archeologists alike concerning the spread of Homo sapiens across the world. One such mechanism is explicable using the Out of Africa theory, which proposes that Homo sapiens could have moved out of Africa first as Homo erectus (Bandelt, Vincent & Martin, 76). The first migration resulted in interbreeding of the Homo sapiens with other hominids in the places that they settled. However, the initial movement did not give rise to sufficient genetic material that would have led to the formation of modern humans.
Therefore, the scientists propose that there was a second movement of the hominids out of Africa to other regions and Asia, in particular, this time around when they were fully Homo sapiens. The later migration occurred about 200,000 years ago resulted in a replacement of the initial populations around the world (Bandelt, Vincent & Martin 78). There were different ways, which led to the replacement of the populations of hominids across the continents. For example, one of them proposes that the Homo sapiens possessed better adaptive features to the environment, which made them survive while other suggest that there occurred passive replacements through interbreeding.
Another theory that explains the movement of Homo sapiens across the globe is the multi-regionalist approach, which suggests that human populations existed in the world at the time before Homo eructs (Human Evolution 67). The former populations interbred and resulted in the present man, which qualifies the idea that the Indonesian and Chinese material are the direct ancestors of East Asians while the material found in Africa give a direct evidence of the origin of Africans. Therefore, both theories propose that the spread of Homo sapiens across the world entailed gene flow from one species to another through interbreeding, and the parental forms became extinct with time.
Adaptive Strategies of Homo sapiens and Their Peculiar Qualities
Homo sapiens were the most flexible of the hominid groups because they settled in new regions of the world quickly. For instance, they used adaptive radiation, which referred to the development of features to suit their environments. The advantage that the sapiens possessed was the improved brain intelligence, which made them easy to adapt to new climates such as the colder regions that its ancestral forms had not explored (Coolidge & Thomas 89).
The brain size and intelligence of this hominid made them aware of the implication of the climate and climate change. They also started living in settlements that made them have security and the collaborative effects in their new colonies. Today, the Homo sapiens remain the most intelligent hominids, which puts them in control of the rest of the population. The intelligence that they have gives them the advantage of making rational thoughts and decisions as well as think critically, which is absent in the rest of the population.
The Early Civilization of Homo sapiens
It remains a mystery how Homo sapiens moved from Asia and Pittsburg to the western hemisphere because of the geographical barrier that existed in the form of the ocean. Therefore, there are only theoretical approaches that explain the event. One of the models devised to explain the occurrence is that early man could have entered the western hemisphere by use of a bridge that connected the region to Asia via the Bering Strait, which could have occurred about 40,000 years ago (Coolidge & Thomas 45). Another theory is that there existed an ancestral figure of the human race called the Clovis that lived in the region. Therefore, the theory supposes that there could have been no need for traversing the sea to the Americas.
Modern man also established settlements averagely 10,000 years ago in the Nile Valley of Africa because of his change in lifestyle from hunting and gathering to agricultural settings. The transition helped Homo sapiens to provide enough food for the population, which resulted in the swelling of the population. The community became even stronger and enabled early man to colonize more ecological niches (Coolidge & Thomas 89). Soon, there was migration across all continents because of the increase in the populations of Homo sapiens. The development of agriculture resulted from man’s increased abilities to make tools from iron as well as weapons that enabled him to conquer his environment.
Works Cited
Bandelt, Hans-Jürgen, Vincent Macaulay, and Martin Richards. Human Mitochondrial DNA and the Evolution of Homo sapiens. Berlin: Springer, 2006. Print.
Coolidge, Frederick L, and Thomas Wynn. The Rise of Homo sapiens: The Evolution of Modern Thinking. Hoboken: John Wiley & Sons, 2011. Print.
Human Evolution: Neanderthals and Homo sapiens. U.S: Emilie M. Smyth, 2010. Print.