Mercyhurst Magazine Summer 2016

Photo of Heather Garvin and Jill Scott by John Hawks

Meet Homo naledi Garvin still probing new human species In the spring of 2014, Mercyhurst anthropologist Heather Garvin embarked on the journey of a lifetime. National Geographic Explorer-in-Residence Lee Berger recruited her to join an international team of scientists analyzing a remarkable fnd – an unprecedented quantity of hominin fossils discovered deep in South Africa’s Rising Star cave system. The Rising Star team would later determine the fossils represented a new species of human ancestor and dub him Homo naledi . (“Naledi” means star in South Africa’s Sotho language.) The fnd, announced to the world in September 2015, was described in two papers published in the journal eLife , the cover story of the October 2015 issue of National Geographic and a NOVA/National Geographic Special. Discovery magazine declared “Homo naledi and the Chamber of Secrets” the second most important science story of 2015 (behind only new revelations about the planet Pluto). The new species sheds light on the origins and diversity of our genus, Garvin said, adding that H. naledi has a unique combination of more primitive traits combined with some surprisingly

information about the beginning of our genus, Homo ,” she said. “On the other hand, if they are less than a million years old, it would indicate that there were multiple forms of human ancestors living in South Africa at the same time, and that this small-brained species with climbing capabilities lived alongside larger-brained species, including Homo erectus , which was the frst known hominin to leave Africa.” Regardless of the age, Berger has said the fossils will force anthropologists to rethink long-held theories about human evolution. The Rising Star Expedition is expected to continue as many more fossils remain to be unearthed, Garvin said. While two years have passed since her trip to South Africa, Garvin and her colleagues continue to research H. naledi and publish their fndings. They presented a symposium at the national meeting of the American Association of Physical Anthropologists in April, and Garvin is a coauthor on a paper recently published in the Journal of Human Evolution . The discovery of H. naledi also drew widespread public interest and Garvin has shared her story with audiences ranging from elementary school children to college students to senior citizens. Garvin earned her master’s degree in biological and forensic anthropology from Mercyhurst, went on to earn her doctorate from Johns Hopkins University and then returned four years ago to join Mercyhurst as an assistant professor of anthropology.

humanlike features, including feet nearly indistinguishable from those of modern humans. H. naledi also appears to have intentionally deposited bodies of its dead in a remote cave chamber, a ritualized behavior previously thought limited to humans. Berger and his researchers spent three weeks in 2013 bringing up an estimated 1,550 hominin fossils from an elaborate cave system in a region in South Africa already known as the Cradle of Humankind because of earlier fossil discoveries there. The fossils belong to at least 15 diferent individuals, including eight children, fve adults and two adolescents. Working with the cranial team, Garvin used 3D scanning methods to create a virtual reconstruction of the skull and, from that, estimate the brain size of the new species. Garvin had come well prepared. Through her career research, she had amassed a collection of more than 700 3D surface scans of skulls from around the world. The team concluded H. naledi’ s brain was tiny: 500 cubic centimeters, or about the size of an average orange. Garvin also led the body-size team, charged with determining the height and weight of the species. Her group’s analysis showed that H. naledi stood about 4’10” and weighed approximately 100 pounds. Work is continuing to establish the age of the fossils, Garvin said. “If the fossils turn out to be older than 2 million years, it will give us pertinent


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