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The Story of a Hobbit
In September of 2003 a team of researchers, led by Michael J. Morwood and Peter Brown, both of the University of New England in Australia, made a remarkable discovery. While conducting a dig in a limestone cave on the Indonesian island of Flores, they discovered the fragmentary skull, pelvis and leg bones of a tiny hominid female. When their results were published in the journal Nature (Nature, Vol. 431, 28 October 2004) in 2004 they created an immediate sensation in the scientific community that quickly spread to the public at large. As the “Lord of the Rings” trilogy was at the mid-point of its release, the specimen - at a bit over three feet in height - became known as “the hobbit”. A fossil hominid find is always big news in the scientific community. What made this really big news is that the find was dated to as early as a mere 18,000 years ago, well after any hominid forms other than our own Homo sapiens was believed to have existed!
The researchers reconstruction of the hobbit shows her to have been rather small brained, with a cranial capacity of 380 cc, with a body size that was smaller than those of australopithecines (Awe-stral-oh-pith-eh-seens) such as the famous Lucy. (In comparison, the average modern human brain comes in at around 1300 cc). Despite her small cranial capacity, the researchers determined that other facial and dental traits bore a greater resemblance to a dwarfed Homo erectus. Also found in context with the famous hobbit were stone tools, as well as bones of a dwarf elephant relative named Stegodon, and bones of a now extinct rat that grew to cat size. Later investigations have revealed fragments of bones from as many as eight other similar hominids at the site. Examples of species becoming dwarfed over time when isolated in a small area with limited resources as well as limited predator dangers has been previously observed. However the new hominid species, officially named Homo floresiensis, is most noteworthy for the “when” of her and her counterparts’ existence. Until this find, examples of Neanderthals from western Europe dated to perhaps 30,000 years ago were the oldest examples of someone other than “us”. If Homo floresiensis in fact a dwarfed species of Homo erectus that really upsets the apple cart, as that species was previously believed to have faded away about 400,000 years ago. The fact that resident Islanders still tell folk stories of ebu gogo “the grandmother who eats anything”, little humanlike creatures that roamed the forests, only adds fuel to the speculative fire. Given that everyday Homo sapiens like ourselves have likely inhabited the island since between thirty-five and fifty-five thousand years ago, such tales might well have basis in ancient fact.
Remains of the well-known Homo erectus, which had a body size very close to that of modern humans, were discovered on the large nearby Island of Java in 1891. This find has been dated to 700,000 years before the present (abbreviated as BP). H. erectus remains have also been found over a large area of the Old World, and across a considerable span of time. The discoverers of the “hobbit” theorize that a small population of this hardy hominid species became stranded on the island, and over a long span of time became dwarfed in response to the environmental pressure of living in such a tiny locale.
Controversy quickly sprang up around the diminutive biped. An Australian paleoanthropologist suggested that the specimen was a pygmy Homo sapiens with microcephaly, a genetic abnormality resulting in an unusually small brain. Not long after that, a debate ensued when another scientist at an Indonesian facility “locked up” the specimen for a period of time. Others wondered how a population of creatures with such small brains could produce the relatively complex tools found in association with the remains. Eventually, the specimen was again made available for study by the researchers. As for the size of the brain, other researchers pointed out that size is hardly the only factor in intelligence. Brain size must be factored in with the size of the body as a whole. Computer models of the skull created by a research team at Florida State University strongly support the discovery team’s theory that the hobbit does indeed most resemble Homo erectus, albeit in dwarfed form. Other researchers have studied the data and tend to support the discoverers’ contention that the “hobbit” skull shows many similarities to normal sized Home erectus, differentiating it from Homo sapiens.
Spirited back and forth debate over such a challenging new discovery wonderfully illustrates how scientific knowledge is advanced. The specimen was carefully excavated, examined, and from the examination the scientists put forth the data with their conclusions for review and commentary by their peers. Alternative explanations were put forth and in their turn tested. Of course, Homo floresiensis has only been “on-stage” for a year. Even as her discoverers eagerly go forth to gather new specimens, other scientists in the field of paleoanthropology eagerly continue to examine what has already come to light. While some outside the scientific community have chosen to either deny that the “hobbit” is anything other than a dwarf human with an unusual disease, or to hold her up as a challenge to the existing views on human evolution; paleoanthropologists have generally taken the find to be an exciting sub-plot in the story of how modern man came to be. The “hobbits” represent not our direct ancestors, rather a newly revealed example of how all species diversify and respond to new conditions in an ever-changing world. The Cranbrook Institute of Science has in its own history tackled the story of human origins, with displays of replicas of “Lucy” and other fossil hominids. This year, Cameron Wood, the CIS Anthropology educator, has introduced a school program “Humankind Emerging” that takes a look at the fossil evidence for human evolution. The question of “Where do we come from?” is one of the oldest in human existence. While science cannot perhaps answer that question in its totality, it can provide valuable insight into our species physical origins that can be observed, tested, and evaluated.
Glossary
Australopithecine: A member of the scientific genus Australopithecus, hominids of several species that date back to at least 4.2 million years ago. Australopithecines are generally accepted as ancestral to members of the genus Homo, which includes modern humans.
Hominid: A member of the scientific family Hominidae, which includes all human and pre-human forms. Bipedalism – upright locomotion – is a hallmark of this family.
Homo erectus: A very successful species of the genus Homo. Specimens have been found in many parts of the old world. They existed roughly between 1.8 million years ago to around 400,000 years ago.
Homo sapiens neanderthalensis: Popularly called “Neanderthal Man”, this rugged group existed in Europe and northern Africa. The most recent specimens, from Spain, date to about 30,000 years ago.
Homo sapiens: Modern humans. Fully modern humans are believed to have appeared circa 100,000 years ago. Scientists believed that modern humans spread from Africa, displacing or absorbing other earlier forms (this is also a great current debate) along the way.
Prehistoric forest and river channel found at the bottom of the Great Lakes!
Over the course of the last year John Zawiskie, Institute geologist and research associate with the Noble Odyssey Foundation, has participated in fieldwork and analysis and educational aspects of the submarine geology of two sites in Lake Michigan and Lake Huron. Both center on the geologic history of an extreme prehistoric low stand of the Great Lakes (Early to Mid-Holocene: 10,000 to 7,000 years ago) when water levels were up to 300’ lower than today and half of what is now lake floor was a land area. During this time the Lake Michigan and Huron basins were isolated from each other, joined only by a river channel now submerged on the floor of the straits of Mackinac, and have been named Lakes Chippewa and Stanley respectively.
The Noble Odyssey Foundation (N.O.F.) research team is a group of scientists from local universities and museums and divers that undertake submarine and coastal research projects with logistical and dive support from the Research Vessel Pride of Michigan and the US Navy Sea Cadets (Great Lakes Division) under the direction of Captain Luke Clyburn, who also serves as the Director of the N.O.F. and PADI instructor Kathy Trax who coordinates the diving programs. The Institute has a long history of collaboration with Captain Clyburn and the diving Sea Cadets including a number of research cruises in support of former Institute staff botanist Dr. Jim Wells. He described the flora of many remote islands in the Great Lakes with Captain Clyburn, helping make the Institute herbarium collection one of the finest in the region.
Last summer (2004) John Zawiskie and marine biologist Dr. Elliot Smith (formerly a visiting research scientist at the Institute in residence at Edison House) directed the underwater mapping of the geology of the sill at the mouth of Grand Traverse Bay leading to the creation of the first geologic map of the bottom sediments and bedrock in that part of the lake basin and documentation of a drowned river channel cut through lake bottom clay at depth of up to 150 feet. This is a relict channel from the low stand period that formed when the current lake floor was a land area, sometime between 10,000 and 7,500 years ago. A DVD that chronicles the preparation for the expedition and the fieldwork and an accompanying teacher activity guide geared to the Michigan Curriculum Framework benchmarks can be obtained by contacting the N.O.F.
During the winter of 2005 John also participated in the analysis of geological data from another N.O.F. project concerning an extensive drowned forest from the low stand period in Lake Huron, now submerged in 40 feet of water off the coast of Lexington. This was a long-term study lead by Dr. Doug Hunter, a biologist from Oakland University in collaboration with researchers at the Laboratory for Tree Ring research at the University of Arizona and Center for Wood Anatomy Research, USDA Forest Products Laboratory in Wisconsin.
The forest bed was systematically mapped over a square kilometer area and is the largest drowned forest reported from the Great Lakes, including ten in place tree stumps and hundreds of log, branch and root specimens. Growth ring analysis indicates several stands of trees were present at the site between 7,000 and 6,400 radiocarbon years ago, when rising lake waters drowned the last trees. The forest was a rich conifer cedar swamp dominated by northern white cedar and eastern hemlock with coexisting pine, spruce and ash, indicative of a relatively cool groundwater influenced wetland. The age of the youngest trees provides an important constraint on the timing of the reflooding of the southern Lake Huron basin several hundred years before the establishment of the modern St Clair River drainage 6,100 radiocarbon years ago. It took a remarkable set of geological circumstances to cause the extreme prehistoric low stand of the lakes. It does however provide a model for the type of conditions that climate change and massive diversion of waters from the Great Lakes could induce.
Links and contact information for the Noble Odyssey Foundation and the Pride of Michigan:
http://www.prideofmichigan.org/index.htmlhttp://www.nof.homestead.com/
Noble Odyssey Foundation contact information:
Director Captain Luke Clyburn: 248-666-9359; Lclyburn@comcast.net
Draft of Internatinonal Pact on water diversion from the Great Lakes:
http://www.cglg.org
Other collaborative Cranbrook Institute of Science geology projects:
Surface Geology and Hydrology Map of Oakland Countyhttp://www.co.oakland.mi.us/peds/program_service/es_prgm/geology.html
Explore our Natural World: A Biodiversity Atlas of the Lake
Huron to Lake Erie Corridor:
http://www.epa.gov/glnpo/ecopage/stclairbiodiv/
For further information contact John M. Zawiskie: 248.645.3252; jzawiskie@cranbrook.edu.