Chapter 21: Divide and Prosper

1. Since 99.99 percent of all species that have ever lived are now extinct, it is absurd to argue that any one species has found the ultimate winning formula in the struggle for survival.

2. But longevity is not the only measure of biological success. An ecological approach calculates the total weight of all the organic material on earth - the biomass - and then estimates the portion accounted for by each major life-form.

3. According to this method, the larger the share of the biomass held in the tissues of a given life-form, the greater its ecological success. For instance, mammals outrank all vertebrates, while ants dominate the invertebrates.

4. Each worker ant is an individual animal, but since it cannot reproduce, it is not a complete organism. The organism - or "social organism," as it is called - is the ant colony as a whole. For the organism's genes to survive, all components must make their particular contributions.

5. Of the roughly 10,000 species of ants the 238 species of leafcutters employ the most elaborate division of labor. The physical dimensions of the work define the physical dimensions of the workers.

6. Not coincidentally, the earth's other leading land-animal species - us - also achieved its ecological dominance by forming partnerships with plants.

7. The leafcutters solved the efficiency problem biologically, by evolving physical size. Humans, by contrast, used their brains. They invented farm tools.

8. A species' population growth -- its success in absorbing an increasing share of the earth's biomass -- does not imply a rising standard of living.

9. Unlike the leafcutter/fungus partnership, the human/technology partnership allowed humanity to tap an energy supply external to the food web.

10. The epochal shift from agriculture to technology did not mean the evolutionary process had been abandoned. Whether an economy happens to be based on genetic or technical information, the same rules apply.