paleoanthropology, evolution and genetics

Photo Credit: Hillside above the Rising Star cave system, South Africa. John Hawks CC-BY-NC-ND

A visit to the world's largest body farm

Vox writer Joseph Stromberg visited the Forensic Anthropology Center at Texas State University, and has written an in-depth description of his visit: "The science of human decay: Inside the world's largest body farm". The article features the work of Daniel Wescott at Texas State, and provides a great account of how the science of human decomposition developed.

The article gives some historical perspective, describing how Bill Bass got started studying decomposition at Tennessee, and goes into some detail about how today's research differs from that history. Among other things, forensic anthropologists have developed a much stronger understanding of the microbes that are involved in decomposition:

For Wescott and the other researchers, caged decomposition presents the most interesting scientific experiment at the body farm. It was once thought that the bacteria that drive decay are simply the same species inside you while you're alive, but it's since been discovered that a succession of different species carries it out over time. Some of them are indeed present during life, but others are brought to the body by flies and beetles. Meanwhile, some bacteria species release chemicals that actually attract particular kinds of insects — and proteins in those insects' saliva kill off competing bacteria. Further, these insects are prey for mice, which in turn attract rattlesnakes and other larger predators. A decomposing human body, it turns out, creates a remarkably complex, tightly evolved, and underappreciated ecosystem. Scientists are now calling it the necrobiome.

This seems to be decomp week in the media, which is probably due to Halloween coming up this Friday. But this article is really superb. I will be distributing it to my introductory anthropology students when we approach our forensic anthropology inquiry at the end of the semester.

One important thing to note is that all the research is done upon bodies that are donated for this purpose. Body donation has become incredibly important to anthropological work of all kinds. The article has a sidebar that discusses the reasons why people donate their bodies for science, and why the study of decomposition can be a really important avenue for body donation.

One thing that the article doesn't discuss is the scientific value of the bones, after the body's use in decomposition research has ended. Some decomposition research does involve damage to the bones (the article discusses the effects of vultures; some decomposition research also investigates the effects of cremation). But the overwhelming majority of bones become available for accession into study collections at these forensic anthropology research centers.

The skeletal material from the University of Tennessee forensic research unit constitutes the single most important collection for understanding variation within the skeletons of living Americans. Most collections of human skeletal material in museums and universities were acquired early in the twentieth century, or represent archaeological remains. Those are important collections, but do not represent today's biology -- people today are much heavier, live longer, suffer fewer ill health episodes early in their lives, and often survive surgeries and skeletal implants when they reach advanced ages. To understand how human biology affects bone today, and to understand the variation in bones of living people, new collections are incredibly important. They are literally priceless, because collections of this kind cannot be bought. They result only from the generosity and interest of donors who leave their remains for this purpose.