Evolution of Civilization

An interesting short article answering this question:

Why Haven't We Found Civilizations Older Than 7000-8000 Years?

The questioner wondered why, if our species evolved hundreds of thousands of years ago, it took so long for human cultures to make the transition from a hunter-gatherer lifestyle to a civilized one.

Here "civilization" means the standard definition of settled city life with classes of people who specialize in various occupations. Several conditions are required for civilization to develop:

Most importantly, agriculture is necessary to produce enough of a food surplus to free some subsets of the population to specialize in other skills and be supported (through trade, patronage, etc.) by the farming class. Agriculture needs at least two preconditions, as outlined in the article—favorable climate and a critical mass of population (for agriculture to have a significant advantage over hunting and gathering; if a society is small enough that it can feed itself by hunting and gathering, there is no incentive to switch to the harder work of farming). Both of those conditions were fulfilled after the last Ice Age gave way to the present "interglacial" period we're living in.

"Civilization" in this sense is probably a prerequisite for advanced technology. To produce the kind of high-tech society we now have, you need people free to work full time in highly specialized fields of research, engineering, and manufacturing. Therefore, an SF author creating a space-faring alien culture has to give the aliens a home world and an evolutionary history that allow for agriculture, settled living, and vocational specialization (even if that worldbuilding never explicitly gets into the story). If the aliens come from a radically different kind of background, how they developed the capacity for space travel probably needs to be explained.

That article links to a Quora page exploring another intriguing question: Why haven't other animals evolved intelligence equal to ours?

Why Didn't Other Animals Develop Intellect Like Apes?

What are the minimum prerequisites for developing intelligence (once you get past the hurdle of defining "intelligence," of course)? As far as we can tell from observing ourselves and other animals with an intellectual edge over their closely related evolutionary counterparts, some of the factors seem to be belonging to a social species, having manipulative organs to interact with the environment, having access to abundant nourishment to support a big brain, and possibly being omnivorous (because having to search for food and determine what's good to eat encourages problem-solving). When constructing a sapient alien species, it's desirable to consider how they evolved to become intelligent, keeping these factors in mind.

Margaret L. Carter

Carter's Crypt