April 25, 2003

• The Cost of Living

  
  Let's start with sharks. There's no point in going back to forms earlier than the vertibrates for this discussion.
  
  The shark is a fairly primative fish, mostly boneless. It is a predator and scavenger. Its fins are useless for manipulation, so it is limited to grabbing things with its mouth once its body is properly positioned. Its teeth aren't anchored in bone and break off easily, so they have to be replaced frequently, one price of being a shark. Many sharks have no mechanism for pumping water through their gills when at rest, so have to be constantly in motion in order to breathe, making sleep impossible, another price of being a shark. The cold blooded shark, when cold, may have his metabolism slow so much that what he eats may remain incompletely digested for months.
  
  Now let's look at some herbivores. Digesting plants isn't easy. The animal, whether a small rodent or a large hooved creature, has to consume large quantities of material that has to be finely ground; even so, a long small intestine is necessary and the animal needs the help of bacteria to break down the plant material. At any given time, the animal will be carrying around large amounts of partly digested food within his body. The small energy gains from this diet doesn't lead to a very active life style, much of the energy going back into the digestive process. What this means, in particular, is that, on an evolutionary scale, only enough energy is devoted to intelligence to permit bare survival; in other words, diet limits intelligence, their price of living as they do.
  
  Herbivores are often prey species. They are so actively hunted that it shows in the end product of their digestion. A predator or omnivore has the leisure to squat to eliminate the excess weight of digested material, in order to gain speed. Prey species have to be able to eliminate on the run. This shows up in the evolution of pelleted poop. Mice, rabbits, deer and many others have developed the ability to drop pellets as they run to escape their attackers, another price of living developed over evolutionary timescales.
  
  Eating meat is more efficient than eating grass; it gives more energy and is easier to digest, requiring less gut for the process. Our ancestors may have discovered this, starting as much as four million years ago. Some speculate that those ape-like creatures followed leopards, scavenging their kills from the trees where they were hidden and then doing something the leopards were unable to do, breaking open the long bones with stones to get at the marrow within. Marrow is a good high-energy food. However they got their meat, those apes had an increase in intelligence because of their change in diet.
  
  Eating raw meat still has a high price. The fossil record clearly shows that when fire was discovered and, presumably, used to cook our food, brain capacity increased quickly. Our race got smarter. The price of living got smaller.
  
  Now things began to cascade. We had our hands free to manipulate our environment, we developed a complex vocal aparatus and a language that gave us new dimensions, new ways of approaching our environment. We gave ourselves history. We've built tools that have taken us to the fringes of space, approaching the capability of escaping this world that would otherwise doom our species within another half billion years.
  
  It took a lot of surplus energy to build that first set of superior brains, capable of converting rocks and bones into superior tools, capable of making the use of sounds into a tool for survival and advancement. The price having been paid, that energy wasn't just thrown away. We are still building on it in newer and more inventive ways.
  
  Once you've paid enough, you get lots of dividends.
  
  Message Board

  • 14:54
  • 6 Comments