We are part of Sapiens, which is just one of the multiple human species that have existed

I've started reading Sapiens: A Brief History of Humankind, by Yuval Noah Harari, and - if you're interested in people at all - it's a gripping read with each and every paragraph. It's broken into four parts, or revolutions: cognitive, agricultural, the unification of mankind, and scientific. My multi-part overview begins with Part 1 on the start of The Cognitive Revolution.

Harari's timeline at the beginning includes the most crucial of stats and puts everything nicely in context. That was what was missing in another history of humankind I recently read, A Little History of the World, by E.H. Gombrich. (Side conversation: If you’re looking for a chronological human history, Gombrich's book is a little all over the place and probably not for you. That said, his humor - and the narrator in the audiobook is very good too - is really well worth the read all by itself.) 

Back to Harari:

• Matter and energy appeared 13.5 billion years ago - the world of physics beginning about 300,000 years later with the Big Bang. The world of chemistry began with atoms and molecules interacting.
• Earth was formed 4.5 billion years ago. Then, about 3.8 billion years ago, the world of biology started when molecules formed organisms.
• Fast forward to 6 million years ago, when humans and chimpanzees shared the last of their immediate relatives.
• The genus Homo - species that evolve from a common ancestor and which are very closely related to modern humans (Homo Sapien self gratuitously means wise man) - evolved in Africa and invented the first stone tools 2.5 million years ago.
• Humans spread from Africa to Eurasia 2 million years ago.
• Neanderthals evolved in Europe and the Middle East 500,000 years ago.
• After an astoudingly long time continuing to exist and evolve in the cold, fire was invented and being used daily 200,000 years ago.

Harari's narrative begins 70,000 years ago with "The Cognitive Revolution," with this being essentially the start of our history, language emerging, and Sapiens finally spreading beyond Africa (long after other types of human species did). They settled in Australia 45,000 years ago, alongside the extinction of that continent's megafauna. Neanderthals became extinct 30,000 years ago. Sapiens setted America 16,000 years ago as American megafauna went extinct. 

From about 2 million years ago to 10,000 years ago, there were several different human species roaming the world. It wasn’t exactly like the posters we see of apes slowly progressing into modern humans. It was just like how today there are many species of dogs, foxes, bears, and pigs. Someday there very likely could be multiple human species on Earth as well.

If you traveled back 150,000 years ago, most scientists agree there were humans walking around East Africa that looked pretty much like us today. 70,000 years ago they started spreading through Eurasia. There are differing theories, but it seems most likely that Sapiens somehow killed off Neanderthals and everyone alive today harkens back to that original Sapien species from East Africa. This species made its way from Africa to Europe and Asia then to Australia and North America and finally to South America. There is some evidence and ongoing research to determine if Neanderthals weren’t completely killed off but actually merged with Sapiens and still exist in some small percentages to this day.

Homo Sapiens have long viewed ourselves "as set apart from animals. But that's just not the case. Like it or not, we are members of a large and particularly noisy family called the great apes. Our closest living relatives include chimpanzees, gorillas, and orangutans. The chimpanzees are the closest. Just 6 million years ago, a single female ape had two daughters. One became the ancestor of all chimpanzees, the other is our own grandmother."

Humans have paid dearly for our many advantages. While being upright is nice because we can scan the landscape for threats and use our hands for things like throwing rocks at those threats, it is not easy to carry upright our heavy brains. These big-head-causing brains also have made it so we need to be born premature for mothers to survive childbirth, which is why it takes us a much longer time than animal babies, which typically start walking, eating on their own, and doing other mature things much faster than humans. 

The human place in the food chain, until recently, was right in the middle. We only jumped to the top about 100,000 years ago. While species like sharks and lions evolved over a much longer period of time to rule the food chain, humans ascended quickly, which made us “full of fears and anxieties over our position, which makes us doubly cruel and dangerous.”

Fire was huge for us to because we could chew and digest our cooked food in an hour or so while chimps would take about five hours to do the same thing with raw foods. Cooking is believed to have “opened the way to the jumbo brains of Neanderthals and Sapiens.”