a drunkard’s walk through a minefield, roughly matching fortuitous accidents to changing circumstances.
Human Evolution
Summary: If you understand that Earth has experienced 4.5 billion years of history and life has existed over 3.8 billion of those years, you grasp the concept of deep time. If you understand organisms have incremental success in both surviving and procreating, traits (and mutations) are heritable, and you combine this with deep time, then you grasp evolution. If you understand our hominid ancestors lived in small tribes of 50-150 on the savannah of Africa for hundreds of thousands of years, you are visualizing our ancestral environment — the crucible from which uniquely-human traits emerged. We know modern dogs evolved from wolves in the past 25,000 years 20 . Gradually, the precursors to modern dogs were artificially selected for those traits which were beneficial to humans. More recently, hundreds of different breeds of that same species were further selected for working, hunting, companionship, etc. The behavioral tendencies of the different breeds of dogs are testament to this historical selection process. Similarly, humans, as we now exist, were ‘selected’ (though by natural forces and ecological interactions, not by another species) . Imagine yourself living in a tribe of 100 people — what sorts of behaviors would have led to survival and mating success? We can never know, other than by anthropological, molecular and genetic clues. But based on species we can observe, we can guess they included: access to food and water, social status and acceptance within the
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