From bees to birds to humans, the animal kingdom is filled with organisms that have evolved complex social structures to deal with specific problems they encounter. Explaining why some species have evolved more complex societies than others has been a major challenge in social animal research and can best be approached with tools from complex systems, according to a team of researchers at the Santa Fe Institute.
Some scientific concepts of complexity are already part of the lexicon of biology. For example, evolution and adaptation are fundamental to both areas. In a recent article in Animal behavior, four current and current PhD students at the Santa Fe Institute offer three additional concepts in complex systems science – organization, compression, and emergence scales – that could be particularly useful for researchers studying the complexity of animal sociality.
"Neither of these three concepts is in itself a diagnosis of a complex system, but all three are often part of one," says Elizabeth Hobson (Cincinnati University), a former postdoctoral fellow and senior authority at SFI. "These concepts could take us in completely new directions and offer new insights into the social complexity of animals."
The four paper authors come from wildly different perspectives, says mathematician Joshua Garland (Santa Fe Institute). Garland and Hobson, along with SFI PhD student Artemi Kolchinski and former SFI Fellow Omidyar Vanessa Ferdinand (University of Melbourne), scope areas including information theory and neuroscience, cultural evolution, mathematics and animal behavior. "The scope of the fields has made it challenging to agree on only three concepts, but the diversity of perspectives is an advantage of this document," Garland says.
The first concept – social scales – is important to consider when measuring complexity in animal societies, as the level of complexity may vary across scales. For example, the interactions of two separate bees can be quite simple, while the hive's organizational structure can be very complex.
The second concept – compression describes how systems encode information. Animal researchers could use compression to better compare different animal systems with each other, or to describe possible cognitive processes that allow social animals to remember relationships and group structures. "It can help us understand how animals reduce their overall cognitive load while functioning in their societies," Hobson says.
The ultimate concept, emergence is when a new model, often at a higher level of social organization, emerges from lower-level interactions. A classic example is the wavy behavior of a large flock of birds – something that cannot exist on an individual level. Other social behaviors, such as dominance hierarchies, culturally learned behaviors, or group leadership, may also exhibit emergent traits.
Hobson and her co-authors suggest that researchers consider these tools when examining measures of social complexity for animals. "Taken together, we hope that these three concepts of complex systems can help us better cope with longstanding questions about the social structure of animals and help better compare sociality between different species," says Hobson.
"These are three big concepts that are important and immediately applicable," Garland says. "but they are simply scratching the surface of complex systemic ideas that may be useful for examining animal welfare."
Materials provided by Santa Fe Institute, Note: Content can be edited for style and length.