Our ancestry does not begin with the first written records, nor does it begin with the earliest Homo Sapiens. It goes back to the first emergence of life on this planet.
Our planet has been calculated to be about 4.5 billion years old, just 30 million years younger than the Sun. The first simple cells, our ultimate ancestors, emerged about 3.8 billion years ago and this gradually led to the appearance about 1 billion years ago of multicellular life. More complicated organisms, insects, fish, plants, birds, reptiles and mammals developed over time, with the first human-like species appearing a bit more than 2 millions years ago. The only surviving Homo species, Homo Sapiens (us) is thought to be only about 200,000 years old, having evolved in east Africa.
Currently the most accepted theory, based on DNA and archaeology and known as the 'Out of Africa' theory, states that a single small group of Homo Sapiens (the number varies from 2 dozen to 150 depending on the source you read) crossed the strait at the bottom of the Red Sea about 50,000 to 80,000 years ago, at a time when sea levels were much lower than they are now. From there, over thousands of years, they fanned out across the rest of the Earth's surface, displacing the earlier Homo species such as the Neanderthals, who had also originated in Africa. So everyone other than native Africans is descended from these few people. Everyone at that time is thought to have had dark skins, evolution and adaptation accounting for the variation in skin and hair colour we now see. Racial characteristics such as those seen in Chinese, European and Asian populations are thought to reflect the characteristics of the parent families.
Coming more up-to-date, research published in 2008 has indicated that our default eye colour is brown, and that everyone with blue eyes is descended from one individual who lived about 10,000 years ago in the area of the Black Sea.
We probably think of ourselves as the ultimate and final form of human life, but as research shows, newer, better models have so far continued to evolve. Will Homo Sapiens eventually be replaced by a new improved model?
The above is a very brief round-up of the latest research on our very early ancestry. If you are interested and would like to know more there are many web sites devoted to these subjects. So rather than give you links to any particular web site I suggest using the following seach terms in your search engine.
Origin of Earth Origin of Life Out of Africa Theory Origin of Blue eyes
Books on the 'Out of Africa' theory include Out of Eden: Peopling the World, by Stephen Oppenheimer | The Journey of Man: a Genetic Odyssey, by Spencer Wells | Deep Ancestry: Inside the Genographic Project by Spencer Wells
on evolution, showing how we are related to just about every living
thing on Earth.
DVD The Incredible Human Journey Dr Alice Roberts BBC DVD, which is also available as a book of the same title.
going even further back, how the Earth, possibly uniquely in the Universe,
became suitable for the evolution of intelligent life.
I am aware that there are other theories for the existence of the Universe, the Earth and of the life thereon other than Darwinian Evolution. While not accepting them myself, if you are interested the main ones are Creationism and Intelligent Design.