Sharks, bees and humans use same mathematical pattern to hunt
A mathematical pattern of movement called a Lévy walk describes the hunting behaviour of many animals, including sharks, birds and honeybees, and now for the first time it has been shown to describe human hunter-gatherer movements as well.
The Lévy walk pattern involves a series of short movements in one area and then a longer trek to another area on a discrete grid rather than in a continuous space. It appears to be ubiquitous in animals, similar to the golden ratio , phi, a mathematical ratio that has been found to describe proportions in plants and animals throughout nature.
When sharks and other ocean predators can’t find food, for example, they abandon their normal motion, for Lévy flight. Birds and other animals also seem to follow Lévy flights and research has shown that it is optimal for searching sparsely and randomly distributed targets.
Now new research has shown that the same pattern applies to humans too. University of Arizona anthropologist David Raichlen, studied the movements of one of the last hunter-gatherer tribes on Earth, the Hadza people of Tanzania, who still hunt on foot using traditional foraging methods. Members of the tribe wore wristwatches with GPS units that tracked their movement while on hunting or foraging bouts. The GPS data showed that while the Hadza use other movement patterns, the dominant theme of their foraging movements is a Lévy walk.
"This movement pattern seems to occur across species and across environments in humans, from East Africa to urban areas," said Adam Gordon, study co-author and a physical anthropologist at the University at Albany. "It shows up all across the world in different species and links the way that we move around in the natural world. This suggests that it's a fundamental pattern likely present in our evolutionary history."
The researchers have pointed out that following a Lévy walk pattern does not mean that humans don't consciously decide where they are going, Raichlen said. "We definitely use memories and cues from the environment as we search," he explained, "but this pattern seems to emerge in the process."
A Lévy flight stems from the mathematics related to chaos theory and is useful in stochastic measurement and simulations for random or pseudo-random natural phenomena. Examples include earthquake data analysis, financial mathematics, cryptography, signals analysis as well as many applications in astronomy, biology, and physics.