Patrick Guilfoile: What is eating you?
I’ve had the experience of hiking and backpacking in grizzly bear country several times.
Wondering whether you might become a snack for a large predator can really focus the mind. Every unexpected noise, especially at night, left me wondering whether there was a mass of claws, muscles, and teeth just beyond my vision. It also made me wonder what it must have been like for our ancestors on the African savanna. Surrounded by predators, were they fearful? Did they sometimes get eaten? Those types of questions are often only amenable to conjecture. But a recent report from researchers at a university in South Africa provided some insight into the lives of early humans.
The scientists were studying 200,000 year-old fossilized hyena droppings (12 in total), part of an ancient hyena “latrine” located in a cave in central South Africa. They researchers focused on fossil hairs in the droppings because they wanted to understand the diet of long-dead predators, something difficult to do hundreds of thousands of years after the fact.
These fossil hairs had become rock, so they no longer contained any protein or other biological substances, but they retained the size, shape, and other characteristics of the original hairs.
The scientists studied these fossil hairs by pulling them from the surrounding material with a tweezers, coating them with gold, and then magnifying them up to 2500 times in an electron microscope. Researchers compared the magnified images with the magnified images of hairs from other mammals in order to identify the species. The pattern of scales on the surface of the hairs was one of the key characteristics they used to identify the different species associated with the fossil hairs.
Using this method, the scientists identified hairs from warthog, zebra, and impala in the fossil droppings. They also indentified one hair as being a human hair. This provided an indication of the mix of mammals present in this region of Africa, long ago. One thing that can’t be determined directly from this research is how the hairs ended up where they did.
Hyenas are both scavengers and predators. Consequently, in some cases, the hairs were likely from animals killed by other predators, and some were likely from animals the hyenas had killed themselves.
In modern-day Africa, human corpses are sometimes eaten by hyenas, and hyenas, on rare occasions, have also attacked and killed people.
Therefore, it isn’t certain whether the human hair made its way into that dropping thousands of years ago as a result of an attack by a hyena, or following death from another cause. But this research does suggest that our ancestors had a lot to worry about when they lived in the African wilderness. More information is available in the article: “Identification of fossil hairs in Parahyaena brunnea coprolites from Middle Pleistocene deposits at Gladysvale cave, South Africa.” by Phillip Tarua, and Lucinda Backwell in the Journal of Archaeological Science Volume 40, Issue 10, October 2013, Pages 3674–3685
PATRICK GUILFOILE has a Ph.D. in bacteriology and is the associate vice president at Bemidji State University.