Meet Australopithecus deyiremeda. A new relative joins "Lucy" on the human family tree. An international team of scientists, led by Dr. Yohannes Haile-Selassie of The Cleveland Museum of Natural History, has discovered a 3.3 to 3.5 million-year-old new human ancestor species. Upper and lower jaw fossils recovered from the Woranso-Mille area of the Afar region of Ethiopia have been assigned to the new species Australopithecus deyiremeda. This hominin lived alongside the famous "Lucy's" species, Australopithecus afarensis. Lucy's species lived from 2.9 million years ago to 3.8 million years ago, overlapping in time with the new species Australopithecus deyiremeda. The new species is the most conclusive evidence for the contemporaneous presence of more than one closely related early human ancestor species prior to 3 million years ago. The species name "deyiremeda" (day-ihreme-dah) means "close relative" in the language spoken by the Afar people. Australopithecus deyiremeda differs from Lucy's species in terms of the shape and size of its thick-enameled teeth and the robust architecture of its lower jaws. The anterior teeth are also relatively small indicating that it probably had a different diet. "The new species is yet another confirmation that Lucy's species,Australopithecus afarensis, was not the only potential human ancestor species that roamed in what is now the Afar region of Ethiopia during the middle Pliocene," said lead author and Woranso-Mille project team leader Dr. Yohannes Haile-Selassie, curator of physical anthropology at The Cleveland Museum of Natural History. "Current fossil evidence from the Woranso-Mille study area clearly shows that there were at least two, if not three, early human species living at the same time and in close geographic proximity." "The age of the new fossils is very well constrained by the regional geology, radiometric dating, and new paleomagnetic data," said co-author Dr. Beverly Saylor of Case Western Reserve University. The combined evidence from radiometric, paleomagnetic, and depositional rate analyses yields estimated minimum and maximum ages of 3.3 and 3.5 million years. There are of course some who disagree, and there is still a school of thought that Australopithecus afarensis was the only human ancestor during that period. However there is now fairly substantial evidence to show that they were not, and that during Lucy's time, other hominin species also existed in the same region and area. Scientists have long argued that there was only one pre-human species at any given time between 3 and 4 million years ago, subsequently giving rise to another new species through time. This was what the fossil record appeared to indicate until the end of the 20th century. However, the naming of Australopithecus bahrelghazali from Chad and Kenyanthropus platyops from Kenya, both from the same time period as Lucy's species, challenged this long-held idea. Although a number of researchers were skeptical about the validity of these species, the announcement by Haile-Selassie of the 3.4 million-year-old Burtele partial foot in 2012 cleared some of the skepticism on the likelihood of multiple early hominin species in the 3 to 4 million-year range. The Burtele partial fossil foot did not belong to a member of Lucy's species. However, despite the similarity in geological age and close geographic proximity, the researchers have not assigned the partial foot to the new species due to lack of clear association. Regardless, the new species Australopithecus deyiremeda incontrovertibly confirms that multiple species did indeed co-exist during this time period. This discovery has important implications for our understanding of early hominin ecology. It also raises significant questions, such as how multiple early hominins living at the same time and geographic area might have used the shared landscape and available resources. There is very clear evidence to suggest that different species inhabited the same area during the same time. The new species, A. deyiremeda have smaller teeth, which could suggest a more meaty diet, a shift or difference to A. afarensis. And it is possible that the foot could belong to A. deyiremeda or even another species. Reported Wednesday in Nature, the new specimens—a partial upper jaw, two lower jaws, and some other fragments—were found at Burtele, in the Afar Triangle of Ethiopia, just a day’s walk from Hadar, where Lucy was found in 1974. Sediments surrounding the bones were dated to 3.3 and 3.5 million years ago, a time when A afarensis is well known to have inhabited the region. While the new jaws share some characteristics with Lucy’s species, they differ in other respects. Some of the teeth have different root structures, and in general are smaller than A. afarensis teeth, a trait that could indicate a shift in diet. “Smaller teeth are often associated with a more meaty diet,” says Fred Spoor of University College London and the Max Planck Institute for Evolutionary Anthropology. “And the chewing muscles have migrated forward, which suggests a redistribution of chewing forces of some sort.” --------------------------------------------- Of special interest are some enigmatic foot bones of a hominin recovered in 2009 very close to where A. deyiremeda was unearthed. The bones suggest a creature with a flexible foot and big toe capable of grasping objects, similar to a more primitive hominin called Ardipithecus ramidus, dated to 4.4 million years ago. (Read about the discovery of Ar. ramidus in National Geographic Magazine.) But perplexingly, the foot bones at Burtele date back to just 3.4 million years ago: the same time period as A. deyiremeda. It’s a combination of proximity in both space and time that cannot be ignored, Kimbel says. This is an amazing discovery and one which could re-write part of our ancestral history. Especially when we consider the new archaeological find of tools dating to this same period. ------------------------------------------------ Articles cited: "New Human Ancestor Species from Ethiopia Lived alongside Lucy's Species." ScienceDaily. ScienceDaily, n.d. Web. 28 May 2015. <http://www.sciencedaily.com/releases/2015/05/150527134040.htm>. Nadia Drake, National Geographic PUBLISHED May 27, 2015. "New Species of Human Ancestor Found in Ethiopia." National Geographic. National Geographic Society, n.d. Web. 28 May 2015. <http://news.nationalgeographic.com/...farensis-deyiremeda-hominin-human-evolution/>. "Australopithecus Deyiremeda: New Hominin Species Discovered in Ethiopia." Breaking Science News SciNewscom. N.p., n.d. Web. 28 May 2015. <http://www.sci-news.com/othersciences/anthropology/science-australopithecus-deyiremeda-02848.html>.
Well sure. Homo sapiens migrated into an area (Europe) populated by Homo neanderthalensis about 30,000 years ago. Evidence strongly suggests that they coexisted for thousands of years. But the Neanderthals were at a disadvantage, with physiology better suited to surviving in cold climates and to hunting the large, slow-moving herbivores that were being replaced by smaller, faster ones. Nonetheless, the presence of Neanderthal DNA in the Western Indo-European population of Europe (descendants of the Celtic, Germanic and Italic tribes) indicates that the two species made peace with each other and even interbred. Surely every sapiens tribe could benefit by having a few Neanderthals in their camp.
