A BRIEF ANTHROPOLOGY OF SHELLFISH
One person’s trash is another’s treasure, they say. Well in this case, we’re talking about ancient trash. Middens are refuse deposit sites within a previously occupied area that can provide information about the diet and lifestyle of the people who lived there.
Middens can contain a myriad of artifacts- bones, biologic matter, lithics, pottery. But in this case, we’re focusing the queen of all garbage dumps, shell middens. Consisting of massive heaps of shellfish debris (up to 30 meters high), shell middens are extremely common, across the globe & throughout human history. They were everywhere. Shell middens are a piece of history that have survived time, demonstrating the extensive and significant relationship between humans and shellfish.
So, how long have humans been eating shellfish? In short, we’ve been eating shellfish longer than we’ve been humans. Anthropologist Curtis Marean discovered the first evidence of early humans consuming shellfish in a cave, now high above sea level, in South Africa (1). His research found that between 195,000-123,000 years ago, early humans in the area made a significant shift in their eating habits from foraging and hunting on land to relying on predictable shellfish beds for sustenance (4).
Pause for a few facts- it is generally agreed upon that humans became physically modern 200,000 years ago (meaning their bodies looked like ours do) but they became cognitively modern 50,000 years ago (meaning they thought like we do).
Among the shellfish remains in Marean’s South Africa site, archaeologists found small stone blades and red ochre, a rock used by early hominids to make pigments for decoration- jewelry, cave art, burial sites, for example. While the tool use and shellfish collecting show sophisticated behavior, the presence of red ochre demonstrates symbolic behavior (4). The use of symbolism reflects higher thinking, use of language, and the beginnings of culture much earlier in the human timeline than previously thought.
Check it out- all of the thinking you’re doing right now is symbolic, whether you’re thinking about what you’re thinking (metacognition), or thinking about waiting to be done reading this article (imagining a future that doesn’t exist), or just creating arbitrary sounds with your larynx that another human can understand (language). Humans are entrenched in symbolism, it is what we are, it is where we come from.
So, this find is incredibly intriguing because this is the earliest evidence we have of systematic use of marine resources that is also accompanied by some of the earliest examples of beahvioral and cognitive modernity in early humans (1). Basically our ancestors at this time looked like us and used their brains to think like us and, in turn, fed themselves with shellfish.
However, it is becoming more apparent across the study of anthropology that early humans were not the only hominids demonstrating sophisticated behavior and thinking during the Middle Paleolithic. Research has found that Neanderthals, whose existence overlapped with that of modern humans in time and space, also exploited coastal environments, systematically collecting shellfish like their “higher” Homo sapiens counterparts.
While excavating a Neanderthal cave in Portugal, archaeologists discovered huge deposits of mussel and limpet remains dating to 106,000-86,000 years ago. The scale that these Neanderthals used marine resources was thought to have only been a trait of modern humans (2). However, mounting skeletal evidence suggests that Neanderals spent a significant amount of time diving for shellfish. Many Neanderthals had “surfer’s ear,” a bony growth in the external ear canal that forms with repeated exposure to cold water or wind (3). More and more research of Neanderthals shows us that the systematic exploitation of shellfish and coastal environments accompanied by symbolic behavior is not unique to modern humans, but is more deeply rooted in our ancestral history than previously thought.
But why is everyone so obsessed with shellfish? Marean explains, “Accessing the marine food chain could have had huge impacts on fertility, survival, and overall health, including brain health.” Omega fatty acids present in shellfish are key to brain health and some anthropologists argue that a shift to a marine diet in coastal regions helped drive evolution forward. Marean believes the shift from land sustenance to marine resources happened when early humans learned how to exploit tides (4). While higher intelligence evolved gradually over millions of years and a high consumption of omega fatty acids did not push evolution on its own, there were massive advantages in knowing how to shuck an oyster and track tides. Physiologist Stephen Cunnane summarizes, “Once we were able to access the coastal food chain in Africa—far more rich and reliable than inland sources of fish—brain and cultural evolution exploded” (4).
Today, the consumption of shellfish is tightly woven in many cultures around the world, whether it be daily staples or luxurious treats for special occasions. No matter how often or in what setting you enjoy shellfish, it's lovely to know that you are here today partly due to our ancient ancestors learning how to take advantage of marine environments, munching on dozens of oysters, and tossing the shells into a big heap :)
-Sarah Coombs
Joyce, C. (2007, October 18). Who ate the first oyster? Cave may hold an answer. NPR. https://www.npr.org/templates/story/story.php?storyId=15391834.
Davis, N. (2020, March 26). Cave find shows Neanderthals collected seafood, scientists say. The Guardian. https://www.theguardian.com/science/2020/mar/26/cave-find-shows-neanderthals-collected-seafood-scientists-say?CMP=Share_iOSApp_Other.
Davis, N. (2020, January 15). Neanderthals dived for shells to make tools, research suggests. The Guardian. https://www.theguardian.com/science/2020/jan/15/neanderthals-dived-for-shells-to-make-tools-research-suggests?CMP=Share_iOSApp_Other.
Stetka, B. (2016, March 1). By land or by sea: How did early humans access key brain-building nutrients? Scientific American. https://www.scientificamerican.com/article/by-land-or-by-sea-how-did-early-humans-access-key-brain-building-nutrients/.