Primates are thought to have evolved alongside other placental mammals after the K-T extinction event. They would continue to divide into numerous species over the next several million years.

Around 30 million years ago monkeys had prehensile tails and eyes on the front of their head. Most are thought to have lived in Africa with some migrating to South America, possibly on a raft of vegetation. Five million years later primates would split into apes and monkeys, apes being notable for a lack of a tail.

These early primates spent a great deal of time living in trees, giving rise to hands and fingers to help grip onto the branches. It is thought that this lifestyle also lead to sight being the dominant sense in primates as opposed to smell as in other mammals. It is easy to see that better eyesight would have given a significant advantage when swinging through the trees. Shoulders in apes had a great deal of freedom of movement, as well as other adaptations such as wrists, a wide flat ribcage and shoulder blades on the back. Around seven million years ago the descendants of humans split from those of chimpanzees.

After a further four and a half million years of evolution the first species of the Homo family appeared, Homo habilis. Alongside homo habilis lived homo erectus, which would go on to evolve into homo sapiens. Around 700,000 years ago the last common ancestor of homo sapiens and the neanderthals was alive. The two species would remain separate but lived alongside each other for thousands of years until the neanderthals became extinct.

With the arrival of homo sapiens 250,000 years ago the planet would undergo extensive changes. The key factor that allowed humans to go on and dominate in the manner that they have is due to the large brain and greater mental capacity than other animals. Humans would discover the use of tools and language, therefore reaching a level of communication and cooperation far beyond other apes. The hands that had evolved to climb in trees would prove invaluable in creating tools and later art and writing. The use of tools would allow humans to hunt for meat as well as fish, and language and arts would lead to complex social groups eventually culminating in civilisation. Early tools were made from flint and stone, but later development would see tools made from bones and fragments of antlers.

At around 40-50,000 years ago humans would undergo rapid changes known as The Great Leap Forward. During this time finely made tools, fishing, trading, jewelry, art, music, games and burial of the dead were all developed. This time would also see the expansion of the human population out of Africa and into Europe, Asia and Australia. 12,000 years ago at the end of the most recent Ice Age humans had colonised much of the planet. As the ice receded human populations would continue to grow.

The next key to human development was the arrival of agriculture. While arising at different times in different areas it is thought to have first started around 10,000 years ago in the Middle East. By 2700 BCE agriculture had spread to India, Egypt, China and Mesoamerica. Irrigation, growth of crops and domestication of animals gave humans an early control over their surroundings. Religion also started appearing during this time.