The Great Demotions and the Promotion of the Human Race

Sagan had talked of the “great demotions.” Humanity had learned, painfully, that it did not live on a planet at the center of the universe, and further demotions followed. We were not (in Sagan’s view) the purpose of the Creation, not specially chosen by a divine authority, and were in fact just one evolutionary twist in a complicated biosphere shaped by the mindless process of natural selection. If we were ever to make contact with another intelligent species, those aliens would in all...

 Sex as a Survival Strategy

In 1966, George Williams exposed the logical flaw at the heart of the textbook explanation of sex. He showed how it required animals to ignore short-term self-interest in order to "further the survival and evolution of their species, a form of self restraint that could have evolved only under very peculiar circumstances. He was very unsure what to put in its place. But he noticed that sex and dispersal often seem to be linked. Thus, grass grows asexual runners to propagate locally but commits...