Work on a New Species at Lincoln Memorial University

As a physical anthropologist specializing in paleoanthropology, Dr. Zach Throckmorton researches soft tissue as well as foot and ankle variation and evolution.

An assistant professor of anatomy at Lincoln-Memorial University’s DeBusk College of Osteopathic Medicine, Throckmorton was one of only twenty-five junior scientists selected from hundreds of applicants across the world to participate in a workshop on new fossil material that started with the discovery of over 1,000 fossil remains in a cave about thirty miles from Johannesburg, South Africa.

Becoming Part of the Rising Star Team

Initially, the fossil remains were discovered about 100 yards from the Rising Star cave entrance, accessible only through an extraordinarily narrow chute; just a handful of small and slender “underground astronauts” were able to retrieve the bones. Throckmorton believes his experience in studying human feet is a likely reason he was chosen to be among the select team of junior scientists awarded the opportunity to be part of this groundbreaking research, as one of the distinct factors that separate humans from animals is our bipedal nature.

As he began comparing the newly discovered H. naledi and humans, he was surprised by the similarities. He and his team discovered the species was able to stand on tiptoes, that the foot was rigid (like human feet) and that the ankle joints even had a similar range of motion to that of human ankles. These discoveries, among others, helped the researchers determine that H. naledi is part of the same genus, a close relative of our own. Determining that the fossils were from a species that walked upright put them in Homo genus, as walking upright is a definitive feature of human lineage.

When Throckmorton has invariably been asked the “Missing Link” question, however, he is quick to point out that the concept of a missing link is faulty from the start, as there are millions of links to human ancestors. What they can safely say is that H. naledi is a close relative of humans and that they lived in South Africa, though no one can yet estimate how long ago that may have been, and scientists will likely have challenges in determining an exact timeline.

A Treasure Trove for Future Research

One thing all researchers agree on is that the number of specimens has offered an amazing opportunity for future research, as this is the largest single fossil find on the African continent, and there are individuals of all ages—from infants to the elderly—available to study. When National Geographic alerted the world to the new species, the work was only just beginning for the scientists with the Rising Star. Throckmorton notes it will take them years to do scientific analysis, which will be followed by bone imaging and analysis as well as detailed CT scans.

Throckmorton considers himself a minor player in all of this, while he credits technological advancements as the key to the discovery, by both transforming the way science is done and altering our ability to share this information with non-scientists around the globe. Simply put, though, in response to the “swelling of support” that has come from his colleagues at LMU and other universities, as well as from national and international media outlets, Throckmorton shares, “It’s been nice to see the interest in what I do.”

Commitment to Open Access Research

Dr. Kimberly Congdon, of Southern Utah University’s Department of Biology, calls the opportunity to work on the H. naledi fossils “genuinely unique.” In addition to praising the sheer volume of fossils to work from, she notes that the lead scientists’ commitment to open-access research allowed a large and diverse group of people to come together and collaborate to analyze the findings. “By combining so many people with such a range of backgrounds and expertise, what we really had was a world-class paleoanthropology think tank, in which a much more holistic approach to the reconstruction of this species was possible than is typical of most hominin studies,” Congdon states.

When you also considered how much they enjoyed working together, she adds, the experience was as pleasant as it was productive—leading to relationships that would certainly extend beyond the time in Africa. She says she now has “a long list of trusted future collaborators, as well as a brilliant example of how true open-access science should, and can, be done.” That the digital scans have remained available to all interested researchers demonstrates their commitment to open access.

Throckmorton was drawn to the open-access angle of the project as well. Because many smaller private colleges don’t have access to some of the more expensive journals, he knew how important it was that the research be equally available to all scholars—and even non-scholars for that matter. They wanted all material to be free of charge and accessible to anyone with the interest to learn more, even creating 3D laser scans of the fossils and virtual reconstructions (so anyone with a 3D printer could create their own copies to work with).

Congdon mentions that within days of the scans becoming available, she knew of multiple anthropologists incorporating them into their current data sets and ongoing projects. “I really hope other anthropologists with access to fossils choose to take the same route in the future,” Congdon adds. “We can very easily revolutionize the way anthropology is done with the technology available to us these days, so why aren’t we?”

Prioritizing Research over Familiar Faces

Biological Anthropologist Dr. Caroline VanSickle of University of Wisconsin-Madison also found working on the Rising Star project to be an amazing experience, offering both a field-changing discovery and an unmatched collaborative experience pulling together team members from around the world.

Like VanSickle, Rising Star team member Dr. David Green praises the diversity of the team. Though he knew many of the people involved in his project ahead of time, as their field is not very large, he had a chance to work and socialize with new people; he found the opportunity to network with people at different institutions invaluable, though a potentially precarious move by project head Lee Berger. “It was certainly a risk for Lee to include so many people that were ‘untested’, but Lee understands that folks in the throes of their dissertation (or recently completed) will have had the most time to collect comprehensive datasets, since that is essentially our job.” Because of his own experiences, Green feels junior researchers may be best equipped to describe H. naledi from a comparative and anatomical perspective.

VanSickle states, “The team reflected the importance of prioritizing quality research skills over familiar faces; many of us were early career researchers, still unheard of in our specialties, but who had the most up-to-date data sets and training in the most advanced techniques for studying hominin fossils.” In working together, they used the fossils to support an announcement of a previously unknown species, but their immediate goal thereafter was about sharing that information publicly as quickly as possible.

“We wanted to stir public interest in human evolution while also making the data we collected and virtual scans of the bones themselves immediately available to other researchers,” VanSickles adds. “Good science is science that can be repeated or checked by other researchers, which can only happen when data are open access. We want any challenges to our work to be based on scientific evidence rather than the reputation of big names.”

Throckmorton notes that with three dozen people and sixteen institutions representing a dozen countries, there was never any doubt among team members that this information belonged to everyone. Because the fossils were so plentiful, there was never a fight over ownership. He uses the analogy of feeding ten people with one plate of food to explain why the abundance of research made in-fighting and territoriality unnecessary. This was, he explains, “an entire buffet to feed ten people—no one fights over anything.”

Genealogy on a Grand Scale

One of Throckmorton’s other team members with the Rising Star project is Dr. David Green, an Assistant Professor in Midwestern University’s Department of Anatomy. Green’s team focused on the upper limb, as his research specialty is focused on the comparative anatomy of ape and human shoulders. Each team was focused on their respective pieces, as the team leader, Lee Berger, wanted findings described and published before the year’s end, even though the workshop was—of course— only the beginning of the study. “The study of these fossils will not end with the eLife papers, the recent Nature Communications papers, and the other ‘team’ papers which are currently under review,” Green explains.

Like Throckmorton and other team members, Green finds the open-access angle one of the most refreshing aspects of the Rising Star Workshop. Making the fossils digitally accessible through all available 3D scanning technologies offers an unprecedented approach to research sharing in the field. In agreement with his Rising Star peers, Green believes that limited access to material—regardless of the reason—both “hurts our science and prevents new ideas from being formulated and tested.”

Green shares that the finds have garnered international attention not just because of the new species of genus Homo that has been unearthed, but the unusual circumstances surrounding their discovery because it appeared the hominins were purposely “buried/placed” inside the cave after death, a behavior associated with modern humans and Neanderthals.

Throckmorton believes that this discovery is “part of our shared heritage as humans.” That’s just one of the reasons he works to be involved in the outreach and working to share all of their findings with scientists and non-scientists. He wants anyone to appreciate the import of the discovery and feel connected to their findings. “It’s just genealogy,” Throckmorton concludes, “on a grand, abstract scale.”

About the Author
Rachel James Clevenger earned her B.A. and M.Ed. degrees from Mississippi College. After finishing her PhD in Composition and Rhetoric, she taught and served as the University Writing Center Director for Birmingham Southern College and University of Alabama at Birmingham. Most recently, she taught Business Communications at Samford University.