The Sonoran Desert near Gila Bend, Ariz. (John Miller/Associated Press)

Skeletons can tell stories.

In the Sonoran Desert, a body laid gently on its side, its arms crossed, its knees bent toward its chest, tells the story of someone who was loved and respected, whose community mourned her once she was gone.

But James Watson is interested in bones that suggest a different narrative. The University of Arizona bioarchaeologist studies “atypical” burials — bodies tossed haphazardly into graves headfirst, their bones broken, their limbs splayed.

In a new study in the journal Current Anthropology, Watson and doctoral student Danielle Phelps argue that these burials are a sign of the violent circumstances surrounding deaths that happened thousands of years ago.

“These people were buried very differently than the rest of the community, and we're trying to understand why that is,” Watson said in a news release. “We're arguing that the way they were tossed into these pits is a form of continued desecration of the body. It's moving from violence on the living individual, through to the process of death, to violence on the corpse.”

The year 2100 BC marks the start of the agricultural period in the Sonoran Desert, the 100,000-square-mile expanse of saguaro cactus and creosote that covers Southern California, Arizona and northwestern Mexico. The inhabitants of this harsh and stunning landscape were just beginning to establish villages and cultivate farmland.

That cultural shift came with “growing pains,” Watson said. Communities that were once able to peacefully coexist on the land increasingly came into conflict as they sought to establish territory and assert control. Tensions between and within communities eventually boiled over into bloodshed. Fights broke out, leading to blood feuds that could last generations.

Bodies buried by family members were arranged in a flexed position on their side (left), while in atypical burials, bodies were left in more awkward positions (right). (Caitlin McPherson/University of Arizona)

Bodies buried in a clumsy or disrespectful fashion are commonly associated with victims of “bad deaths” — people who died in a manner considered unnatural or evil. Many scholars think that the atypical burials in the Sonoran Desert belong to people accused of witchcraft.

But Watson and Phelps point out that ancient people in this region had an established burial practice for accused witches — usually involving some sort of dismemberment — and that these bodies don't fit it. Instead, they point to the broken bones and projectile points uncovered in the graves as evidence that these people died violent deaths.

That the victims were handled so brutally after they were killed suggests “signaling” — a way of making a statement to the rest of the community about the person who died and the person who killed him. Desecrating the body of a vanquished enemy can be a means of gaining prestige, which in turn “has a potential to confer biological benefits,” Watson said. “You can gain access to power and wealth, including wives, and have more offspring.”

But the practice has a price. Disrespectful burials of people who were violently killed increase the likelihood of retaliation and could potentially turn the victor into someone else's next target.

Watson thinks that it's a form of what evolutionary biologists call “costly signaling” — a risky signaling behavior that has major potential benefits, like big game hunting (which signals power, strength and the ability to provide food, but comes at great physical risk) or bright, colorful plumage in birds (which attracts females but also could draw the attention of predators).

“By creating these atypical burials — where they're basically desecrating the bodies of the people killed — they're signaling their prowess to gain status,” Watson said. “But it's at a very significant potential cost, and that is either their life or lives in their community or family.”

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