In today’s Academic Minute, Dr. Adam Gordon of the University at Albany discusses a common behavioral pattern found in living things from honey bees to humans.
Adam Gordon is an assistant professor of anthropology at the University at Albany where his research interests include the evolution of size and shape in non-human primates, modern humans, and our fossil ancestors. His current projects include an examination of sex-specific size responses to ecological factors and an analysis of the diversity of size and shape of fossil hominins. He holds a Ph.D. from the University of Texas at Austin.
Dr. Adam Gordon – Human Foraging Patterns
Whether you're talking about sharks, jellyfish, or humans, there ain't no such thing as a free lunch. The idea behind this common adage, that it always costs something to get something, means that animals foraging for food tend to use search strategies that maximize the probability of finding resources while minimizing the energy consumed to get there. When food is patchily distributed in the environment, an optimal random search pattern known as a Lévy walk is used by a variety of animals. This mathematical pattern involves mostly movement over relatively short distances before pausing or changing direction, interspersed with rarer longer movements to areas farther away. The Lévy walk pattern appears to be ubiquitous among animals searching for food when the searcher has little or no knowledge of food distribution patterns. However, our research group wanted to know whether human beings, the most cognitively complex foragers on the planet, also used Lévy walks to find food.
To answer this question, my colleagues David Raichlen, Herman Pontzer, and Brian Wood worked with the Hadza people in Tanzania. The Hadza are one of the last groups of people on Earth that still forage on foot for foods ranging from underground tubers to big game. Study participants wore wristwatches with GPS units while searching for food. We then analyzed data from hundreds of foraging bouts and found that while the Hadza use a variety of movement patterns, the dominant pattern is the Lévy walk. What is remarkable is that despite humans' ability to create mental maps of the landscape and to predict the locations of various foods, we often use search patterns that are indistinguishable from those of organisms that are as cognitively simple as jellyfish. The recognition of this basic pattern of human movement may help us eventually understand the movement patterns of our human and non-human ancestors.