AUDIE CORNISH: Natural history museums generally have vast collections of scientific specimens stashed away. This next story is about a surprise find in one collection that's been sitting around for more than a century. It's an ancient mussel shell and NPR's Nell Greenfieldboyce reports strange markings on the shell may tell us something about the evolution of our species.
NELL GREENFIELDBOYCE: Back in the late 19th century, the idea that humans had evolved was pretty radical. It fascinated a Dutch physician named Eugene Dubois. In 1891, he was digging for fossils on the island of Java in Indonesia.
JOSEPHINE JOORDENS: To try and find what he called the missing link between apes and modern humans.
GREENFIELDBOYCE: That's Josephine Joordens of Leiden University in the Netherlands. She says Dubois did find the bones of an apelike creature that walked upright - the first example of Homo erecuts, an extinct human species that lived long before modern humans. It's a famous discovery. Less well-known is that Dubois collected a lot of other stuff from that archaeological site.
JOORDENS: Many other animals and plants and, you know, fish and birds and shells. And they've been stored in a museum - Naturalis - now for over a hundred years.
GREENFIELDBOYCE: Joordens was looking at the shells because she wanted to understand the environment that those early humans had lived in. A colleague photographed the shells and later in one photo of a big white mussel shell he noticed something odd.
JOORDENS: It has a kind of zigzag engraving. So it looks like a pattern that sometimes you still find nowadays on, you know, pottery for decoration.
GREENFIELDBOYCE: To Joordens and her colleague, it just didn't make any sense. Homo erectus used tools, but was thought to be too primitive to think abstractly or make symbolic designs.
JOORDENS: We looked at it and we thought well, it's kind of strange and maybe some animal made it or it's - I don't know - sands grains or maybe even a fake.
GREENFIELDBOYCE: The researchers ended up doing an exhaustive series of studies on this shell and others and came to the conclusion that Homo erectus was actually pretty sophisticated. In the journal "Nature," they say it's clear these early humans had come up with a clever trick to open the shellfish, drilling holes in a particular spot on the shell. They also used one shell to make a scraping tool. What's more, all the evidence suggests that Homo erectus really did engrave that geometric design about half a million years ago.
JOORDENS: I find it a very touching find because it's so much similar to what we as humans would make ourselves and that tells you something about this Homo erectus species that we didn't know before.
GREENFIELDBOYCE: And it means complex human behaviors, like art, may go back farther than we thought. This is a big claim to make. Alison Brooks is a paleoanthropologist at George Washington University. She says what's previously been accepted as the oldest human engravings were made hundreds of thousands of years later on chunks of ochre and the shells of ostrich eggs. Those designs are much more complicated than the lines on this mussel shell.
ALISON BROOKS: Even though it's apparently a zigzag pattern, I think there's going to be some controversy about it.
GREENFIELDBOYCE: She says it's possible that Homo erectus made the pattern, but...
BROOKS: Maybe it's not as intentional a design as they implied.
GREENFIELDBOYCE: One person who's extremely skeptical is John Shea, a professor of anthropology at Stony Brook University.
JOHN SHEA: If this is symbolic behavior by Homo erectus then it's basically the only evidence we've got for a species that lived for a million-and-a-half years on three continents.
GREENFIELDBOYCE: He says if it's true, people should be able to find more shells like this and now they'll be looking. Nell Greenfieldboyce, NPR News.
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