After Neanderthals, Homo erectus skulls were some of the first to be found. But researchers are still unsure about this early hominid. We once thought they were a large species that roamed through much of Asia and Africa 1.8 to 1.3 million years ago. We also thought this species evolved into both Neanderthals, and later, modern Homo sapiens. However, many researchers now think that Homo erectus was related to Homo ergaster, an African hominid species at a similar time. And the linage from both Homo erectus and H. ergaster is unclear how it lead to Homo sapiens. Regardless, Homo erectus were an intelligent species that began to use stone tools and lived over a large part of the globe.
AAAS member Jeff Schwartz is an expert in primate evolution who has spent much of his career studying the hominid fossil record. He presents this slideshow about Homo erectus, pointing out the similarities that are found throughout the species and many of the differences between the fossils that may show us different species existing at the same time. He also compares the fossils to H. ergaster and plays with the idea that many of the Homo erectus fossils from Africa may have actually been members of the H. ergaster species, or may be new species we have yet to name. Schwartz is the author of a number of books including: Sudden Origins: Fossils, Genes, and the Emergence of Species, Extinct Humans, The Human Fossil Record, Volume One: Terminology and Craniodental Morphology of Genus Homo (Europe), The Human Fossil Record, Volume Two: Craniodental Morphology of Genus Homo (Africa and Asia), The Red Ape: Orangutans and Human Origins, The Human Fossil Record, Volume Four: Craniodental Morphology of Australopithecus, Paranthropus, and Orrorin, and Skeleton Keys an introduction to human skeletal morphology, development, and analysis.
Check out Jeff Schwartz's other audio slideshow: The difference between Homo sapiens and Neanderthals
Homo sapiens and Neanderthals interbred, in fact some humans of European decent are one to four percent Neanderthal. This audio slideshow explores this topic using educational graphics.