Evolution of Humans

Many historians have depended on documnets, written and sometimes drawn records to trace the begining of history. That was the case for many civilizations that we are going to learn shortly. However, historians have traced existance of mankind and civilization based not only on documnets, yet on the findings of human fossils and artifacts. Those findings are divided into three different stages. 

1. The first stage occured around four million years ago, when the earliest existance of humanlike creature existed in eastern and southern Africa. The humanlike creature is called australopithecines, also known as southern apes. Those southern apes had the ability to walk up straight and make simple stone tools.
2. The second stage in early human development occurred upon the discovery of Homo erectus meaning "upright human being". Thought to have lived over 1.5 million years ago, those creatures had the ability to use large and varied tools.
3. The third and most crucial stage in human development existed around 250,000 years ago upon the discovery of Homo sapiens also known as the " wise human being". Homo sapiens are of two kinds: the first subgroup is known as Neanderthals, and the second subgroup is known as Homo sapiens sapiens. Neanderthals were found near Neander Valley in Germany and also in Europe and Southeast Asia. They are thought to have existed between 100,000 and 30,000 B.C. Neanderthals had the ability to use a variety of stone tools and seem to be the first forms of humans to have buried their dead. Homo sapiens sapiens " wise, wise human being" where found in Africa and thought to have existed between 150,000 and 200,000 years ago. Homo sapiens sapiens began to spread all around the world around 100,000 years ago. All the human race today belong to the same subgroup of human beings, known to be the homo sapien sapien.

Questions:

1. What are the three stages of human development?
2. When where Homo erectus discovered?
3. In your opinion why where the Homo sapiens sapiens able to spread?

Refrences:

Spielvogel, J.J. (2003). World history. Ohio: Glencoe McGraw Hill

Evolutionary Trends [Photograph].Retrived July 6, 2011, from: http://tle.westone.wa.gov.au/content/items/969144ed-0d3b-fa04-2e88-8b23de2a630c/1/human_bio_science_3b.zip/content/001_evol_trends/page_14.htm