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Lesley
Gregoricka Melinda Zeder, Ph.D. "The experience of a lifetime… this program has shown me a world of endless possibilities." |
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Lesley
Gregoricka Melinda Zeder, Ph.D. "The experience of a lifetime… this program has shown me a world of endless possibilities." |
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CSI Sheep: Skeletal Reconstruction and Demographic Analysis Last spring, a mysterious box of animal bones was discovered in
a dark corner of the attic at the National Museum of Natural History.
The animals apparently had been collected sometime in the late Nineteenth
to early Twentieth Centuries in order to study their bones. The bones
were then shipped to the museum after they had been intentionally
buried, most likely to get rid of the flesh. Containing mostly sheep
remains, the box proved most puzzling. It contained no written documentation
of who collected the sample, where it was collected, or when it was
collected. This research focused on investigating the origins of the
box, putting the sheep bones together, and analyzing the herd’s
population. Packing materials found with the bones provided helpful
clues in determining the origins of this mystery. For example, an
unusual plant pod found among the bones helped in pinpointing the
boxes origin. The pod grows only in Africa and Asia, and thus it has
been concluded that the box originated from a tropical region. In
rebuilding the sheep skeletons, the various stages of bone growth
were used to age the individuals, enabling the bones to be matched
into pairs and eventually assembled into individuals. Examining the
wear patterns on the teeth offered valuable age statistics. From these
data, information about the bones found in the mystery box is revealed.
In a normal, managed (domestic) herd, as sheep age, there are proportionally
less older individuals; in other words, more sheep die as they get
older, so a small population of older adults with a large population
of newborns is to be expected. However, this mystery population is
not normal. An unusual number of newborns and older adults dominate
the composition of the box, suggesting that a catastrophic, mass die-off
occurred, selectively picking off the weakest members of the population.
Naturally, the very young and the very old would be much more susceptible
to disease or an early winter than the stronger, young population.
Also, there are no butchery marks on the bones, implying that the
sheep were not killed for food. Consequently, the composition of the
boxed sheep bones is made up of individuals representing the weaker
members of a domestic herd, not a complete herd, suggesting that these
sheep died as the result of some sort of natural disaster. This research was supported by a grant from the
University of Notre Dame NMNH Internship Program in Anthropology |