Once We Were Not Alone; January 2000; Scientific American Magazine; by Tattersall; 7 Page(s)

Homo sapiens has had the earth to itself for the past 25,000 years or so, free and clear of competition from other members of the hominid family. This period has evidently been long enough for us to have developed a profound feeling that being alone in the world is an entirely natural and appropriate state of affairs.

So natural and appropriate, indeed, that during the 1950s and 1960s a school of thought emerged that, in essence, claimed that only one species of hominid could have existed at a time because there was simply no ecological space on the planet for more than one culture-bearing species. The "single-species hypothesis" was never very convincing¿even in terms of the rather sparse hominid fossil record of 35 years ago. But the implicit scenario of the slow, single-minded transformation of the bent and benighted ancestral hominid into the graceful and gifted modern H. sapiens proved powerfully seductive-as fables of frogs becoming princes always are.