KU professor helps discover earliest human tumor ever found
If David Frayer has his way, the word “Neanderthal” will one day no longer be an insult.
For some 25 years, Frayer has fought against the old view that Neanderthals, the human ancestors who populated Europe and some of the Middle East between 35,000 and 200,000 years ago, were a lesser race that lost the evolutionary war. The Kansas University professor of anthropology has argued that Neanderthals were more closely related to today’s humans than people realized.
And now, Frayer has helped discover something else Neanderthals have in common with humans: They could develop tumors.
Frayer is part of a team of researchers that discovered and confirmed evidence of a tumor in a rib from a Neanderthal skeleton more than 120,000 years old. Their findings, published this past week in an academic journal, provide the oldest evidence ever found of a tumor in a human ancestor — by more than 100,000 years.
“Every person likes to find the oldest, or whatever,” Frayer said. “This is the oldest tumor in a human fossil.”
A rare find
Frayer marvels at the sheer improbability that he and his colleagues made the discovery.
The disease that caused the growth is quite rare, even among today’s much larger population. Plus, a Neanderthal was lucky to live to be 35 years old. And there aren’t that many Neanderthal fossils out there: Frayer and his colleagues found the evidence in one of just about 50 rib bones excavated from a site in Croatia.
“Tumors tend to occur in older individuals,” Frayer said. “So, the fact that we have a small sample of ribs, the fact that the Neanderthals were all dying young — it really surprised us to find this tumor there.”
What they found — confirmed by a University of Pennsylvania radiologist through a CT scan — was a cavity left by fibrous dysplasia, a rare, non-cancerous disease that causes tumors to grow in place of bone. The tumor was benign, but the scientists know little about how it might have affected the Neanderthal who developed it, since all they have is an inch-and-a-half-long piece of rib.
The bone has been in a museum in Zagreb, Croatia, since it was excavated near the turn of the 20th century from a cave in the nearby town of Krapina. Some 900 Neanderthal bones were found there, and Frayer goes to Zagreb for about 10 days each year to examine them. He’d noticed the small rib bone with an unusual cavity before, he said, and other scientists had theorized that it might have resulted from fibrous dysplasia.
“It was so strikingly different than what a normal rib is,” Frayer said.
Frayer and some other scientists from Penn, Princeton University and the Croatian Natural History Museum put that theory to the test, and wound up with by far the oldest confirmed instance of a human tumor. (Tumors have been found in dinosaur fossils, Frayer said.) Before, the oldest had been from a mummy in Egypt, about 5,000 years old.
Janet Monge, keeper and curator of the physical anthropology section at the University of Pennsylvania Museum, made radiograph scans of the Krapina Neanderthal fossils in the 1980s and wrote this month’s paper along with Frayer. She said that to realize that at least one disease has stayed largely the same through 120,000 years of evolution is incredible.
“It also shows a special link, in a sense, between ourselves and Neanderthals,” she said. (She and other scientists, by the way, pronounce and spell the word without the “h.”)
Frayer and his colleagues published the discovery about a month after he wrote an op-ed piece that was published in The New York Times. In the column, he came to the defense of Neanderthals, saying they were not the “stumbling, bumbling, mumbling fools” people may think.
“I was surprised they accepted it, to tell you the truth,” Frayer said.
He wrote that DNA evidence has shown that modern people of European descent got about 4 percent of their genes from Neanderthals. He also mentioned his recent research that’s shown Neanderthals were largely right-handed, just like humans. This suggests that they could speak, as the right hand is controlled by the left side of the brain, which is also associated with language. (Other primates that cannot speak, such as chimpanzees or gorillas, do not have a dominant hand.)
“The image of Neanderthals, at least in the eyes of most paleontologists, is changing,” Frayer said.