ABSTRACT
Some 4 to 7 million years ago, an unimposing primate distinguished itself as a hominid by adopting the peculiar habit of walking on two limbs instead of four. One group of these ancestral hominids eventually evolved into the anatomically modern, brainy humans we are today. Other hominid species, represented by their bones, teeth, and stone tool implements, eventually disappeared from the fossil record. The rest of the primates alive during these times experienced similar fates. Some evolved into what are today’s modern prosimians, monkeys, and apes, just as our hominid ancestors evolved into us; others followed the more common evolutionary pathway into extinction.
