During most of the evolutionary history of the modern human animal, Homo sapiens, we lived in a very harsh, hostile environment, perhaps on the African savanna. Even though we no longer live in that environment we are still programmed to function there.

• In our ancestors' environment, food was hard to come by, so today we have a hard time not overeating when we have a chance.

• In our ancestors' environment, life was short, so mature adults had to reproduce early and often in order to keep the species alive. Therefore, today humans are obsessed with sex.

• In our ancestors' environment, it was counterproductive to feel empathy for the animal killed for food, or for the feelings of the neighboring tribe you had to battle for the area's limited resources. Therefore, today most people, unless they are somehow sensitized, remain callous about the lives of other creatures and fellow human beings.

In our ancestors' environment, people had to depend on one another for protection, food, shelter -- just about everything. Therefore, today people naturally have very strong attachments to their family, tribe, county, state, nation or belief system -- even when that family, tribe, county, state,  nation or belief system practices irrational, unsustainable, destructive behavior.

If we are to save Life on Earth we must identify those of our behaviors rooted in programming that is proper for the African savanna but inappropriate or even disastrous for Life on Earth, and change them.