The short answer to the question of human origins has already been triangulated by genetics, paleontology, and archaeology: 200,000 years ago in sub-Saharan Africa.

So why do we need an entire book just to introduce the subject? Because the long answer is an ever-lengthening saga that contains as many chapters as there are traits that make up the human species. Different aspects of Homo sapiens arose at different times to build the creatures we are today. The three tiny bones in our ears for hearing evolved over 100 million years ago, but we did not begin to make musical instruments until at least 100,000 years ago. Each acquisition of a human trait affected events further along the human evolutionary path. It is because of this broader quest for human origins that there is more to discuss than simply "200,000 years ago in sub-Saharan Africa."

If every human drew their family tree all the way back to the beginning of life on planet Earth, each person's history would be identical from the Big Bang until very recently, when our individual histories—the twigs on our tribal lineages—diverged from the branches of other human groups and became geographically and genetically distinct. Just like a person can trace her curly hair back through generations by looking at photographs of her cousins, grandparents, and great-grandparents, the human species can trace its roots back by looking at fossils and genes that reveal our shared ancestries with our extinct hominin ancestors and with our "cousins"—apes, monkeys, mice, horses, fishes, worms, corn, slime molds, bacteria, and every living thing that humans have ever bothered to name.

It is because of our intellect that we often very easily forget that we are members of the animal kingdom, working under and shaped by the same basic evolutionary processes as all other living things. Despite the long list of differences that we imagine separate or elevate us from other animals, we differ from chimpanzees by less than 2 percent of our genetic code (which is not much considering it is 3 billion base-pairs long). Certainly it is our differences from other animals that define us as humans, but it is our fundamental similarities to those animals that eventually allowed us to become humans.

Knowing we are upright, chattering African apes need not send us into an existential crisis, not with the knowledge that each one of us is unique. No two people have exactly the same DNA, not even adult twins. No one in the past or future will ever have the same genetic code as any other person in the past or future, or any other organism for that matter. Each one of us is the result of a single successful, uninterrupted chain of life that began 3 billion years ago. Instead of using this strangely sharp intelligence to wallow in our ordinary primateness, we should, instead, marvel at what natural selection and other biological forces produced from an ancestor with monkey-like brains.

As arguably the only self-conscious creatures on the planet, it is shocking how little we know about ourselves. Many people, if asked, will tell you they are a "Homo sapien," incorrectly assuming the species in our scientific name is plural. Some people could assemble the parts of a sports car down to the last ball bearing, but could not locate their own semi-circular canals, let alone describe what they do. (They are in the ears but they have nothing to do with hearing. They are involved in seeing clearly while the head is moving around.)

Through oral and written histories we immortalize our family genealogies, we even name our babies after their ancestors, but we can rarely be bothered to remember the very long, strangely pronounced names of our extinct evolutionary ancestors. Next to the anatomy books on our library shelves are volumes instructing us in the basic aspects of life, things other animals do instinctually or learn from one another without spoken or written language, like reproducing, raising offspring, making friends, running efficiently, hunting effectively, eating the right foods, and surviving in "the wild" without a mobile phone.

In the following pages, the overwhelming evidence for human origins and evolution and the fundamental concepts used to interpret that evidence are introduced and discussed as only humans can do, with an arbitrary system of symbols printed on processed tree pulp. Reading about the first spear throwers, prehistoric mammoth-hunting injuries, or the first sea-faring journey to Australia should be like reading about the miraculous throwing arm on your great-uncle, about how your great-grandfather died reeling in a 150-lb fish, or about how your great-great-great grandmother emigrated to America on a boat from Ireland.

It is my hope that readers of Human Origins 101 take away this important tenet of human origins studies: we are modified African apes that, despite seemingly great variation in biological and cultural ornamentation, share a common African ancestor. We are all one diverse species with regionally varying physical characteristics that are the results of environmental adaptations, mate preferences, migration, or simply chance. Culture has a significant effect on the differences we perceive in other people. Underneath the t-shirts, face paint, piercings, tattoos, mohawks, and stilettos, we are all remarkably similar. It is because of our unique makeup that we have both the propensity to forget and the ability to embrace that we are an integral part of the natural world around us.

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