Will Paleoanthropologists Kill off the Homo heidelbergensis Hominin Species?

“If someone kills one person they go to jail,” anthropologist Zeresenay Alemseged of the California Academy of Sciences in San Francisco noted last month at a meeting here in France's deep south. “But what happens if you kill off a whole species?” The answer soon became apparent: anguished debate. In the balance was Homo heidelbergensis, a big-brained human ancestor generally seen as a pivotal figure during a murky period of evolution. At the invitation-only meeting, researchers debated whether this species really was a major player—or no more than a paleoanthropologists' construct.

The big-brained H. heidelbergensis has claimed an important perch in the human evolutionary tree: It's regarded by many as the common ancestor of modern humans and our extinct closest cousins, the Neandertals. Dating to roughly half a million years ago, it is thought to link those species and the earlier H. erectus, which had spread across Africa, Asia, and Europe beginning 1.8 million years ago. But based on a new look at the incomplete fossil evidence, some scientists argue that the picture was much more complicated, and that the transition between small-brained H. erectus and larger brained hominins occurred multiple times. If so, the concept of a single, multicontinental, intermediary species could dissolve into a plethora of hominin specimens with no single name to unite them.

At the meeting, held near the cliffside Arago Cave where French prehistorians Henry and Marie-Antoinette de Lumley found one of the key fossils in 1971, this debate went further, as researchers sparred over whether this supposedly pivotal species existed. One researcher began her talk with a call for “a moment of silence for the death of H. heidelbergensis.” But to others, such as anthropologist Philip Rightmire of Harvard University, the announcement of the species' death was definitely premature. “Homo heidelbergensis is likely to stay with us for a little while longer,” Rightmire said. He argued that this species fits up to 20 specimens from Europe, Africa, and Asia dated to between 800,000 and 200,000 years ago, just before H. sapiens appears in Africa.

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