Watching a group of animals flocking together may be a beautiful or terrific experience. It may be beautiful for the stressed urbanite that leaves the city to breath fresh air and, suddenly, while ambling through the countryside, perceives a dark and moving cloud, which, in fact, is a drove of birds migrating to warmer regions. On the other hand, it may be a nightmare for the farmer who observes a herd of insects streaming towards his crops to ravage them. But in either case the astonished spectator inevitably asks himself how can thousands of animals agree in what direction should they move in such an efficient manner. Nonetheless we, the humans, are very inefficient taking collective decisions.

Scientist also appreciate the beauty of moving herds, but them, as we expect, after the initial reaction, try to answer the inevitable question. So did Ian Couzin of Princeton and his biologist colleagues that sign an article published on Nature in which they account for how big groups of animals transfer information and achieve consensus when its members cannot recognise each other.

Contrary to first expectations, this processes only obey to three simple rules: The main priority of each animal is to avoid collisions, however individuals don’t want to stay alone, so try to travel near and alongside their neighbours. Finally, some members of the group have an information their naive congeneres don’t and, as a consequence, try to travel in a preferential direction. For example, in a colony of bees the informed individuals would be a small number of explorers that would be able to guide the rest of the colony to a field of flowers.

Observing the evolution of simulated birds flying in a digital environment, Couzin and his team have found that groups made of a large number of individuals only need a small number of informed members to travel towards their target accurately and, surprisingly, the larger the group, the smaller the proportion of informed individuals needed. Moreover, in case of disagreement between leaders, the group travels in the direction preferred by the majority of them, even though, no leader knows there is a disagreement because they cannot recognise each other and are not able to send or receive the slightest signal.

This article may seem uninteresting for non-scientists, after all, the movement of fish, birds and bees is not a priority in our everyday lives. But, in fact, these scientist have developed a method to coordinate groups of entities with low cognitive capabilities. This knowledge has many applications. For example, groups of robots could use this algorithm to find their way without human intervention while exploring our oceans, deserts or, even, other planets. Decisions would be taken accordingly to information gathered locally. Furthermore, this article may open a new way to understand the dynamics of systems far more complex than the ones mentioned. In fact, around us, there are many systems where a limited number of leaders determine the future of the whole group in a subtle way similar to the one described in the article: the dynamics of human crowds is a good example.

Once more, we have seen that observing nature not only helps us to answer basic philosophical questions but also we may learn a number of new methods and techniques applicable to the industry. It is well known that a number of medicines, glues or materials have been found observing our environment. Now we are starting to acquire a new kind of knowledge from nature, a knowledge that is not represented trough chemical relations but through algorithms. That may have important consequences in society based on information.

Arxivat a Uncategorized
Etiquetes: Ciència/Tecnologia