The 80%

"As a relatively young species, we have an adolescent propensity to make a mess: we pollute the air we breathe and the water we drink, and appear stalled in an age of carbon dumping and nuclear experimentation that is putting countless species at risk including our own. But we are making undeniable progress nonetheless. No European in 1800 could have imagined that in 2000 Europe would have no legal slavery, women would be able to vote, and gay people would be able to marry. No one could have guessed a continent that had been tearing itself apart for centuries would be free of armed conflict, even amid terrible economic times. Given this record, even Lynn Margulis might pause (maybe).

Preventing Homo sapiens from destroying itself à la Gause would require a still greater transformation—behavioral plasticity of the highest order—because we would be pushing against biological nature itself. The Japanese have an expression, hara hachi bu, which means, roughly speaking, “belly 80 percent full...”"

State of the Species | Orion Magazine