Sunday, October 7, 2018

Pre-hominid Tool Usage Dated To 3.3 MYA

In 2011, stone tools were spotted eroding from sediment laid down 3.3 million years ago, making them the oldest ever found. Up to 8 inches long, these tools are larger, heavier and less refined than those of the 2.6-million-year-old Oldowan type, the previous record-holder of the oldest tool title. Like Oldowan tools, the Lomekwian tools were clearly modified with intention, Harmand says. The maker mainly used a two-handed technique, holding a core on another large rock, or anvil, and hitting it with a hammer stone to release sharp flakes.

Until now, stone tool knapping and the abstract thought it requires have been credited to the genus Homo, beginning with Homo habilis, the presumed originator of the Oldowan style. But the Lomekwian toolkit, reported in Nature in May, predates H. habilis by half a million years. So far, all the candidates for making the Lomekwian tools are pre-Homo species, including Australopithecus afarensis of Lucy fame, and Kenyanthropus platyops, discovered in 1998 near the Lomekwi site. Says Lewis, “If it’s a non-Homo species, that’s a big game changer.”

Getting A Grip:
“To learn learn more about the evolution of the “power squeeze” — the grip we use to hold a hammer — University of Kent anthropologist Matt Skinner compared hand and wrist bones from living and extinct hominids using 3-D X-ray technology. Human hand bones showed increased density in certain key spots associated with toolmaking.
In research reported in Science in January, Skinner found the same modifications in corresponding bones from Australopithecus africanus, possibly a direct ancestor of the Homo genus, which suggests that toolmaking was an earlier adaptation than previously thought. Could this help us identify the Lomekwian toolmakers? “The main point,” says Skinner, “is that there was no Homo around [3.3 million years ago], so it would either need to be Australopithecus or Kenyanthropus who made those tools.”


Human Evolution: The First of Our Kind

A 2.8-million-year-old jaw is the oldest fossil from our genus:

A piece of fossilized jaw discovered in Ethiopia ‘pushes back’ by 400,000 years the date when the first members of the human genus evolved. The jaw is about 2.8 million years old. It’s one of the few hominin fossils that date to between 2.5 million and 3 million years ago, when a small-brained ‘australopith’ was evolving into the larger-brained Homo genus.

During this period, a changing global climate with greater fluctuations (caused by the rising isthmus of Central America cut off the final remnant of what was once essentially a circum-equatorial current that had existed since the Cretaceous) forced our ancestors to live in more open territory than the forests that they evolved in. They had to adapt to new foods and new predators, which may have spurred the development of our distinctly larger brains. Animal fossils found near the jaw fragment suggest the individual lived in a savannah environment.”

It  confirms the idea that our lineage, Homo, is a response to climate fluctuations. If the climate had not changed at 3 million years ago, Australopithecus could still be in existence.

Climate Effects on Human Evolution:

My Comment: Perhaps ‘Homo sapiens’ at our current level of development is not, as a whole, sufficiently ready and willing to face change and manage the next rung of the evolutionary ladder in a proactive manner. If mankind does not cease to overuse and abuse the Earth’s biosphere, then the demise of human civilization is quite possible. The Sixth Great Extinction, that has already begun, may eventually include us. What rises from the ashes may or may not be better. It seems to me, that in order to ensure our species’ upward evolution, we should be more proactive in taking care of the planet that God have us.