Prof, students featured in National Geographic; Excavations yield 10,000-year-old human remains in Alaskan cave When Dr. Timothy Heaton and his students go to work in the summer months, it's a bit of a commute.
First they travel through Canada to Alaska, take two long ferry rides, drive to a remote fishing village, leave their car at a dead end road, jump in a small boat and travel across 10 miles of water to reach a cave from which they excavate artifacts that pre-date the last Ice Age.
Heaton, professor and director of Earth Sciences at The University of South Dakota, has garnered international attention for his paleontological and archeological findings in caves on Prince of Wales Island on the southern Alaskan coast. Heaton and his students are featured in the December 2000 issue of National Geographic magazine as part of an article on the peopling of the Americas. Heaton's work has also been the focus of a Nova documentary film and has been written about in The New York Times.
Heaton's discoveries have yielded two separate treasures. His excavations of On Your Knees Cave, essentially a small, muddy crawlway, have unearthed 10,000-year-old human remains, some of the oldest ever found in North America.
The key significance of this finding, according to Heaton, is that it supports a mostly dismissed theory � that the first people to inhabit North America originally crossed from Asia to North America along coastal waters and not through central Canada's "ice-free" zone, as has been the commonly held view. In addition, the discovery of nearly complete Ice Age bear skeletons and other fossil remains up to 50,000 years old are enabling scientists to study all the climactic changes that occurred before, during, and after the last Ice Age.
Heaton, 41, has been a cave explorer since his youth, growing up and exploring caves near his home in Provo, UT. After receiving his bachelor and master's degrees at Brigham Young University in Provo, Heaton earned his Ph.D. at Harvard University and did his post-doctoral studies at the Smithsonian Institution in Washington, D.C. He joined the USD faculty in 1990, and his first explorations of various caves along the coastal waterways of Alaska followed shortly thereafter, in 1991.
Heaton's particular interest in Alaska was piqued by a boyhood friend, Kevin Allred of Haines, AK, with whom he had spent many hours exploring caves as a teenager. Allred told Heaton he had found fossils in some of the Alaskan caves and Heaton began making summer trips to Alaska to investigate the sites. The discovery of On Your Knees Cave was literally an accident, and Heaton's involvement in it, seemingly predestined.
Road builders had stumbled onto the cave during a logging survey in a clear-cut area of the Alaskan wilderness. During the environmental assessment phase for the road, contractors had unknowingly mapped a logging road directly over the cave. When they saw the hole, they informed local cavers, including Allred, who happened to be working for the environmental assessment firm at the time.
"I first went up there to investigate fossils in 1991 and I excavated several caves before On Your Knees Cave," Heaton said. "I happened to be up there in 1994 to excavate a different cave and we had a delay. Our helicopter couldn't fly because of bad weather, and Kevin took me to check out this cave where he had found several bones.
"Some of the other caves seemed more spectacular because they had big bear skeletons just laid out in the cave, a very visual site," he continued. "On Your Knees Cave seemed less significant at first because only a couple of small, isolated bones were visible, and no whole skeletons. It wasn't until we collected and radiocarbon dated the bones that we found that they were much older, and we realized their significance. They were three times older than anything we had dated previously. They dated to the last Ice Age and beyond."
Heaton and Fred Grady, a colleague from the Smithsonian Institution, immediately applied for, and were granted funding from the National Geographic Society and began a major excavation in 1996. When Heaton began the excavation, he discovered the animal bone deposit was much more extensive than he had ever imagined, and that was followed by the discovery of human remains.
An archeological crew from Denver joined him in the excavation in 1997. Also in 1997, Heaton applied for a three-year, $300,000 grant from the National Science Foundation (NSF) to continue work at the site, which he received in 1998, along with an additional grant for a total of $45,000 from the National Geographic Society.
Human artifacts found in the cave date to the end of the last Ice Age, 10,000 years ago. Although not "old" in terms of human evolution, Heaton says they are significant, being among the oldest human remains ever found in the Americas.
"We do have human remains that are among the oldest in America which would be consistent with the idea that they had come down along the coast to begin with," Heaton said. "They probably jumped from refugium to refugium, big tracks of ice-free land, which they navigated with boats from Asia to arrive in North America, which is what we are thinking.
"This has a lot of significance for how humans first came to America," Heaton continued. "It's commonly believed that America was first colonized by people from Asia, but the disagreements have been from where and when they first came in. It used to be thought that people came down through the middle of the continent, commonly called the 'ice-free' corridor of Canada, from Alaska. There is no fossil evidence old enough in the corridor that would prove that theory. In recent years, new evidence has been found that makes that route less likely. This discovery really opened up and popularized a very minority viewpoint that people first came down along the Pacific Coast."
Heaton notes that during the Ice Age, the sea level dropped and Alaska was essentially part of Asia. The main barrier to traveling to North America was giant glaciers or ice sheets covering nearly all of Canada. The traditional view held by scientists as to how people first invaded the continent of North America was that they came down through the ice-free corridor between several large glaciers. Recent evidence suggests, however, that the coastal route was a very plausible route for humans to move south into North America from Asia and Central Alaska.
"Prior to my work, the theory regarding the Alaska route was not favored because the region was thought to be completely overridden or covered by ice with no exposed land, and my research has proven beyond any doubt that there were ice-free areas available with large communities of animals living on them, even during the coldest part of the Ice Age," Heaton said. "There would have been plenty of food and shelter for humans to make the passage from Asia to North America using those resources.
"The human remains we found in the cave are not the earliest ever found in the Americas, but they demonstrate that people inhabited the coastal islands and had established extensive trading routes by a very early date, by 10,000 years ago," he continued. "It used to be thought that people did not inhabit the islands until much later."
The discovery of both human and animal bones from different eras in the same cave was totally coincidental, according to Heaton.
"It's a fluke that a single cave would end up being the most significant ice age fossil site and the most significant archeological site from the same region," Heaton said. "The cave is not a big shelter where humans would have found refuge, just a tiny, muddy crawlway � not a great place to seek shelter."
The human remains Heaton found had to be after something, perhaps hunting hibernating bears.
"We found spear points and other weapons and charcoal from torches throughout the cave," Heaton said. "It looks like the bear came out the winner in this case!"
Excavation of the cave is not the end of the discovery process. "We finished excavation of that cave this summer and are still actively working in the lab to sort sediment we collected and identify bones we have dated," Heaton said. "Radiocarbon dating the bones only allows dating back to around 45,000 years, and some of the fossils are older than that. We have a complete animal record from 45,000 years ago to the present from this cave. Identification and cataloguing of bones will be ongoing for several more years."
The grant funding from the NSF and National Geographic Society have allowed USD undergraduate students to be involved in both the field and laboratory aspects of the project. The students who have worked with Heaton include Nathan Carter, Mitchell, Jim DeHoogh and Andy Klock, Sioux Falls, Christy Heaton and Wade Sirles, Vermillion, Thomas Haggar, Watertown, Janna Carpenter, Thorne Bay, AK, and Kei Nozaki, Tokyo, Japan.
"This is a rare opportunity for students to see how paleontology and archeology are done in a geologic setting," said Heaton. "They have the opportunity to be on the cutting edge of research and to work closely with scientists in several different fields."