Convoluted human evolution: very old tools (Introduction)

by David Turell , Thursday, May 21, 2015, 21:38 (3474 days ago) @ David Turell

More opinions and thoughts about these 3.3 million-year-old tools:-"The tools "shed light on an unexpected and previously unknown period of hominin behavior and can tell us a lot about cognitive development in our ancestors that we can't understand from fossils alone," said lead author Sonia Harmand, of the Turkana Basin Institute at Stony Brook University and the Universite Paris Ouest Nanterre.-"Hominins are a group of species that includes modern humans, Homo sapiens, and our closest evolutionary ancestors. Anthropologists long thought that our relatives in the genus Homo -- the line leading directly to Homo sapiens -- were the first to craft such stone tools. But researchers have been uncovering tantalizing clues that some other, earlier species of hominin, distant cousins, if you will, might have figured it out.-"The researchers do not know who made these oldest of tools. But earlier finds suggest a possible answer: The skull of a 3.3-million-year-old hominin, Kenyanthropus platytops, was found in 1999 about a kilometer from the tool site. A K. platyops tooth and a bone from a skull were discovered a few hundred meters away, and an as-yet unidentified tooth has been found about 100 meters away.-"The precise family tree of modern humans is contentious, and so far, no one knows exactly how K. platyops relates to other hominin species. Kenyanthropus predates the earliest known Homo species by a half a million years. This species could have made the tools; or, the toolmaker could have been some other species from the same era, such as Australopithecus afarensis, or an as-yet undiscovered early type of Homo.-Dated by studying magnetic polarity:-"The Earth's magnetic field periodically reverses itself, and the chronology of those changes is well documented going back millions of years. "We essentially have a magnetic tape recorder that records the magnetic field ... the music of the outer core," Kent said. By tracing the variations in the polarity of the samples, they dated the site to 3.33 million to 3.11 million years."