The Biggest Picture
Life appears to be a consequence of the universe’s trend toward complexity. Atoms more complex than hydrogen and helium are formed in stars. Heavier atoms join to form complex molecules. Molecules arrange themselves in increasing complexity and life develops (well, once at least – and how that happened is still a mystery). Single celled bacteria joined to form multi-celled critters, which led to us.
A Planet-sized Picture
Life on Earth is a complex adaptive system where the actors are species. Evolution (adaption) happens at the species level. Species compete for territory. Individual critters, whether plants, animals, or fungus, compete for energy. Plants compete for sunlight, which they store in complex chemicals (carbs, for short). Herbivores compete for carbs and store that energy in fat. Carnivores compete for fat.
(Competition drives evolution, according to Darwin. He may have mentioned cooperation as a driving force, once or twice. We’ll be paying more attention to that here.)
Why we hunt
All living things are a teetering stack of complex chemicals kept upright by a continuous throughput of energy. We spend most of our hard-won energy fighting entropy, with a bit left over for reproduction.
Why sex is so great
The simplest life forms reproduce by mitosis, which has only mutation to roll the dice differently. Reproduction through sex adds an enormous amount of variability. In terms of creating complexity, sex is life’s greatest meme.
A New Taxonomy
Here we restrict sex to multi-cellular critters. This is not correct but close enough for this analysis. The old taxonomy had two forms of life: plants and animals. (You missed the fungi there, Carolinus.) A newer taxonomy has three kingdoms; two of single-celled critters and one for all the large critters like plants, animals, and fungus. Here, we opt for a two bin model for life. First, there are critters, or as V’ger calls us, “carbon-forms”. The second is collections of critters. If you want to describe life on earth, you have to take into account how critters act when they get together. Mere mass is enough to trigger new, emergent behaviors. This happens in herds, flocks, schools, and all the variations of man’s gatherings.
Human Collections
Humans differ from animals in the number and variety of the collections they inhabit. The most popular reason critters get together is protection. Procreation is a good reason for creating a (temporary) group of two. Nurturing critters form a family group. Dad doesn’t have to stick around to earn this appellation. The more common form is mom alone raising the kids. In addition, all critters belong a species. That’s the collection one can’t quit. You can leave the herd or leave your kids, but you only leave your species when you die.
Man has experimented with a variety of protective group forms. The smallest was the Band. This was the primary protective group for 90% of human existence (and more if you include pre-humans). The largest, empire, was very nearly next. Empires are generally built on city-states, so they were invented second. The Mongol Empire skipped that step. Since then we’ve had kingdoms, then nation-states. Tribes and clans have not been able to stand up to any of them.
One thing that differentiates between humans and other critters is the creation of groups for other purposes. We have corporations to make money and charities to give it away. We have courts, universities, bowling leagues, and many other institutions. We form groups to get things done. Unless you are an artist, you probably won’t make much of an impact on this world except as part of a group.
Analysis of Complex Systems
Humans are in the process of forming more and more complex societies. Complexity theory is the third great physics meme of the 20th century, after relativity and quantum mechanics. One of the main tenets of complexity theory is the complex adaptive system (link). Species and societies are such systems.
We have tried to analyze complex systems within the standard paradigm (meme) of reductionist science. That didn’t work too well. Reductionism posits that a thing is best understood by separating it into pieces and understanding the smaller bits. This works very well for simple systems. It’s the basis for most of the scientific revolution. However, when the parts (at least three of them) affect each other in a nonlinear manner the math falters. The three-body problem has long been known to be unsolvable. That hasn’t stopped us from trying to model the world in “Newtonian” terms. Mass and center-of-gravity are still part of military doctrine. We now (well, for the past few centuries) have friction in our relationships. Complexity theory holds the promise of a better model.