Introduction

History Begins with Sumer was the title of a book by the American archaeologist Noah Kramer. He published his book in 1956 under the title From the tablets of Sumer  with the realization that Sumer represented the beginning of writing and with that the beginning of what we call History. Prehistory is the period of time from the origin of man to the invention of writing.

Lacking any written records what we know about Prehistory is gained from artifacts such as pottery, statues, weapons and the ruins of stone buildings. One additional way is to go back to earliest ancient written records and see what those civilizations said about the prehistoric period.

While an archaeological site will often be of a known culture that existed during a known time range dating of individual artifacts is estimated by the stratum of soil in which that artifact is found; this is called stratigraphic dating. Using Carbon 14 dating, which is limited to 50,000 years, on an organic object allows an absolute date to be determined for that object and then relative dates can be established for other objects and stratum of soil. The general principle is simply that layers of debris, rock and soil accumulate over time so the deeper in the stratum an artifact is the older that artifact is. It's unfortunate that Carbon-14 dating only allow dating from organic materials; some of the most intriguing artifacts are made from stone, an inorganic material Carbon-14 cannot date.

Tree-ring dating (dendrochronology) is based on variations in the size of tree rings due to changes in precipitation. So an ancient roof beam could be dated by examining the size of the rings in the wood. An iron oven/hearth could be dated using archaeomagnetic dating which relies on the direction magnetized iron points. Both of these techniques can be useful but have a limited time range of several thousand years, so, when looking at prehistory they are of minimal value.

While the origin of writing can be dated to 3400 BC with the first use of pictograms in Sumer the origin of man is more difficult to identify. When we speak of 'man' we're referring to modern man, variously called Cro-Magnon, homo sapien or homo sapien sapien; anthropologists are currently trending towards using the acronyms EMH (Early Modern Human) or AMH (Anatomically Modern Human.) It's also common to see Latin designations such as homo sapien, homo neanderthalensis or homo erectus. The 'homo' in the designation is Latin and means 'man.' So any designation with 'Homo' referres to some type of man while the second word is an arbitrary descriptive term coined by the anthropologist who found some new human like bones. Since we are interested in the origin of modern man we'll primarily consider those species that can mate with man and produce fertile offspring. This will include homo neanderthalensis and homo denisova - we must include these two because modern man contains small percentages of both which indicates we are indeed of the same species.

Creationism
From the earliest written records until the very recent past all cultures in all time periods agreed. Man was created by the Gods and there wasn't any other explanation. While the many stories of the creation of man differs greatly in details they do all indeed agree that God created man.

In Western Civilization our oldest written creation myth comes from the Hebrew Torah (Hebrew for 'Law') of which the first chapter is called Genesis (origin.) The oldest complete version of the Torah is contained within the Septuagint which is written in Greek and dates to nearly 300 BC. The Hebrew 'Babylonian Captivity' is generally considered to be between 597 and 537 BC and it was during their captivity in Babylon that the Hebrews gained access to the ancient written cuneiform tablets of Babylon, Akkad and Sumer. Merging these stories of the creation of man along with their own priestly sources dating back to 800 BC they compiled the Torah. 

And there it was and no questions were necessary. The Torah/Septuagint was worshiped as the word of God and God said he created man. Jesus was himself a Jew who honored the Jewish traditions and prophets so as Christianity developed and spread the Catholics, and later the Protestants, incorporated the story of creation as told in Genesis. Yet even later the Muslims also accepted the creation of man by God and thus all three Abrahamic religions were in complete agreement.

There was a problem with this level of devotion to the 'Word of God' and that problem was a fanatical devotion coupled with the demand that all people agree. This can be seen in European history with the Catholic Church's Inquisition as well as the spread of Islam by the sword. Even Protestantism offered little compromise with the Puritans burning nonbelievers at the stake.

It was against this backdrop of thousands of years of Creationism that a new idea came forward.

Theory of Evolution
Charles Darwin published his book On the Origin of Species in 1859 where he made an argument for the idea of the evolution of a new species from earlier ones. Calling the process 'Natural Selection' he stated this process as the 'principle by which each slight variation, if useful, is preserved.' He attributed the core idea to Classical Greek writers such as Aristotle and Empedocles but avoided the question of human evolution only saying 'Light will be thrown on the origin of man and his history.' However, it was clear from his theory that man would have evolved from apes.

With the advent of DNA analysis in the 1990s there was a clear scientific mechanism which explained how Natural Selection worked in nature. When DNA replicates itself during the birth of off-springs there are occasional errors in the process. These errors are referred to as mutations and produce an offspring which has some characteristic which the parents did not have. These errors are inheritable to the offspring although any given mutation is merely a chance error in the genetic system.

The error may produce a trait which is detrimental, beneficial or neutral to the offspring's survival. Natural selection favor traits that help an organism survive and reproduce more effectively in its environment. But traits which are helpful in one environment might actually be harmful in another.

Manchester, England underwent rapid industrialization during the early 1800. One consequence was an immense amount of soot produced by the coal burning manufacturing plants. The moths in the area were a light tan color and became easy prey for birds who could easily spot them on the blackened surfaces of buildings, streets and foliage. A random mutation occurred where a black moth was born. Being black allowed much better camouflage and over a period of several generations a far greater number of black moths survived as compared to brown moths. The black color was an inheritable trait passed on from parent to offspring and within a hundred years the moth population in Manchester changed from brown moths to black moths. This change in color is an example of evolution at work.

While the above example highlights how environmental conditions can produce evolutionary changes another factor is isolation. An isolated population, such as birds on an island, can no longer interbreed with the larger population of birds so their evolution will favor traits which help it survive on their island. Over many generations, differences in their heritable traits will accumulate to the point where they are so different that they are considered separate species.

Evolution is not only directly observable but supported with the latest scientific advances. This a wonderful example of how science is suppose to work. But, in 1859 the idea that man was descended from apes caused a firestorm of controversy. Today, while the Theory of Evolution is widely supported by most there is still a large subset of humanity, mostly religionist, who adhere to Creationism. However, in order to give fair consideration to all, there is no reason to say it's either one or the other; in fact both may be true! Creation of modern day humans by God could have interrupted, or interfered with, natural selection.

DNA analysis suggests that humans shared a common ancestor with chimpanzees about eight million years ago.