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August 29, 2016

It's not the conclusion that they object to, but the process used to reach it

Read this as a cautionary tale, and not about the danger of falling out of trees.

A study published Monday in Nature Communications claimed to have discovered that Lucy, the 3.18 million-year-old hominid discovered by paleoanthropologist Donald Johanson in the Ethiopian desert in 1974, died from falling from a tree.

Researchers at the University of Texas X-rayed Lucy’s skeleton on a rare visit outside Ethiopia with a machine designed to scan through materials as solid as rock. They believed they found a broken shoulder. After reviewing clinical literature and talking to about 10 orthopedic specialists, they concluded she fell out of a tree.

The problem is they didn’t rule out other possibilities. One of these is that geology works on anything buried for millions of years, said JohansonJohanson is the Virginia M. Ullman Chair in Human Origins and a professor in the School of Human Evolution and Social Change in the College of Liberal Arts and Sciences., founding director of the Institute for Human Origins at Arizona State University.

“It suggests to me that this was the result of geological forces rather than having fallen out of a tree,” Johanson said. “There’s a lot of pressure on these bones when they’re overladen with heavy rock like sandstone.”

The research tries to show that the 3.5-foot, 65-pound Lucy died from the fall from severe trauma, “what they call a terminal velocity event,” said William KimbelKimbel is the Virginia M. Ullman Professor of Natural History and the Environment in the School of Human Evolution and Social Change in the College of Liberal Arts and Sciences., director of the Institute of Human Origins.

However, it’s common for scientists to find the same type of bone breakage in lots of four-legged animals buried in sediments.

“Much of the breakage, trauma and deterioration shown on the bones is shown on so many — I’d say 80 percent — of the fossils we dig up,” Johanson said. Pigs, rhinos and horses “don’t live in trees; they don’t fall out of trees. They live on the ground.”

“I’m not convinced,” he said of the paper.

ASU paleoanthropologist Donald Johanson with the Lucy skeleton in the field
ASU paleoanthropologist Donald Johanson with the Lucy hominid skeleton bones (also pictured above) in the Ethiopian desert in 1974. Photo courtesy of the Institute of Human Origins

 

Kimbel, who has worked for decades at similar sites in East Africa, said he has found damage like this in animals ranging from hippos to hares.

“The probability of any of them having fallen out of a tree is precisely nil, of course,” Kimbel said. He was flabbergasted when he saw the news.

“To be honest, I did a double take and my first reaction was incredulity,” he said. “My first reaction was how could they know that? How could they conclude that?”

The University of Texas researchers relied almost exclusively on clinical literature and clinical expertise. The answers they got were entirely predictable, Kimbel said.

“If you ask an orthopedic surgeon to take a look at breaks like this, what other explanation is he going to give you?” Kimbel said. “The problem is the East African Rift Valley is not an emergency room. There are a wide array of forces that can break bones in this way.”

Where the University of Texas researchers fell short was a comprehensive examination of everything that could have happened, the ASU experts said.

“There are two basic issues here: The issue for science is not being able to tell a plausible story, the issue is to put forth a probable explanation for events that happened in the distant past,” Kimbel said. “The article simply does not offer us enough of a competition between all these competing factors. ... They did not put in place enough of the appropriate scientific safeguards to make this more than just a good story.”

Johanson agreed.

“They didn’t explore a lot of avenues,” he said. He hopes for more research in depth into breakage patterns. “I thought it was an interesting story.”

But not a good one, Kimbel said.

“The point of good science is not to tell a good story,” he said.

If Lucy had fallen out of a tree, it wouldn't change what has been learned from her in the past 42 years, Kimbel said.

“I don’t think anyone seriously doubted she could climb a tree — you can and I can," he said. "It doesn’t bear on the issue of whether she was primarily adapted to life on the ground as a two-legged walker. ... I don’t think it would challenge much of what we know about her biology.”

A cast of the Lucy skeleton on the ASU campus
A cast of the Lucy skeleton is on view in the reading room of the Institute of Human Origins office in the Social Sciences Building on the Tempe campus. Photo by Deanna Dent/ASU Now

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Real-life Raiders of the Lost Ark: ASU grads tame Teo's teaming storeroom.
August 30, 2016

ASU grad students energized by challenge of organizing Teotihuacan Research Laboratory's tens of thousands of artifacts

Editor’s note: This is the third in a three-part series on ASU’s archaeology lab in San Juan Teotihuacan, Mexico. Click for the first and second installments. Lab director Michael E. Smith will appear Wednesday in Tempe to talk about new discoveries; find event information at the bottom of this story.

Step into the storerooms of the Teotihuacan Research Laboratory and the first thing you will think of is the government warehouse at the end of “Raiders of the Lost Ark.”

Shelves rise to the ceiling. Row upon row of cardboard and wooden boxes disappear into the gloom. It looks endless. Ranks of shoeboxes and wooden crates are labeled “figurillas,” end scrapers, sherds, fine knives, obsidian, unifacial perforators.

Ask a normal person to organize this in some kind of coherent fashion and he would become physically ill. It’s a "Sorcerer’s Apprentice" task.

Enter Katie Rush and Lisa Gallagher. They are not normal people. They are master’s students in museum studiesRush and Gallagher's museum studies program is part of the School of Human Evolution and Social Change. at Arizona State University, and they spent more than a month this past summer organizing the vast collection of artifacts, which encompass excavations going back to the 1960s at the ancient city of Teotihuacan in Mexico.

Understand we are not talking simply about things like pots, masks and knives, which you might see in a museum. These boxes hold millions of potsherds, flakes of obsidian and the like, things that mean little to laypeople, but which archaeologists can conjure entire worlds out of.

Gallagher and Rush weren’t horrified when they saw the ocean of boxes. To give an idea, no one knows exactly how many boxes are in the collection. A ballpark estimate of 24,000 is the consensus.

“We knew what to expect,” Gallagher said. “I was very excited when I came into the lab and saw all the work that needed to be done. There’s a sense of pride to be able to come here and help organize these collections that mean so much to Mesoamerican researchers.”

“It’s kind of like a library with objects,” Rush said. “In the collectors’ world, you’ve either got too much info or not enough; there’s never a happy medium.”


Video by Ken Fagan/ASU Now

 

They did a 33-day stint at the lab, which is part of ASU’s School of Human Evolution and Social Change in the College of Liberal Arts and Sciences.

“It’s time-consuming, but it’s not hard,” said Rush. “When you get the flow of things it goes pretty quickly.”

Each researcher cataloged their collection with their own system. What Gallagher and Rush did was create a uniform system for the entire collection. They organized boxes, did data entry and opened containers that hadn’t been opened in decades.

“We’re putting a uniform category on every box, so anyone can walk in the lab and know where it came from,” Gallagher said. “Our goal, when this is all done, is to have a master digitized inventory and have everything be under one uniform catalog.”

Unlike objects in a museum, these artifacts will be moved and handled and unpacked and repacked. It’s not organized for visitors to gawk at; it’s organized for maximum effectiveness for researchers.

For example, there are sample boxes of every type of Teotihuacano pottery: thin orange, gulf fine paste, Metepec. Trading across Mesoamerica was widespread. Researchers from a Mayan dig in southern Mexico might want to visit and see if what they have is from Teotihuacan.

“People want to come and see Teotihuacan pottery looks like,” lab director Michael Smith said. “A lot of people come to consult these.”

“Working with these boxes, it’s not your typical collection,” Gallagher said. “This is a different perspective on collections management. ... It’s designed to be used.”

Smith came to a museum studies class last spring and gave a presentation on Teo and offered two internships to sort out the collection.

“There’s not too many opportunities for students to go out of the country and work in different labs,” Gallagher said. “This is definitely a unique opportunity.”

Rush had done an internship at a museum in Dublin, so she jumped at the chance. She wasn’t familiar with Mesoamerican history and culture before working at the lab.

“It’s very fascinating, and the site is really cool,” she said.

 

Hear Smith speak in Tempe

What: "New Views of the Ancient City of Teotihuacan" lecture.

When: 6-8 p.m. Wednesday, Aug. 31.

Where: Alumni Lounge (Room 202), Memorial Union, Tempe campus.

Details: Free and open to the public. Find more at the events site.