Many different animal species use cooperation to boost their chances of long-term survival, as working in a group can provide benefits in both foraging and protection. These benefits can lead to further cooperation adaptations through evolution, particularly in a changing environment. Now, new research published in Nature finds that when an environment is prone to changing unexpectedly, for some species, staying at home to help raise relatives can be more beneficial than going solo.
“In the last few years, biologists have noticed that high levels of animal cooperation are often found in very harsh and unpredictable places – from birds on African savannahs to bees in the Alps,” says Patrick Kennedy of the University of Bristol and leader of the study. “We wanted to find out whether evolution might work differently in these changeable habitats.”
From this research, scientists believe that helping behavior evolves because the helper is related to the individuals they help. However, this explanation for helping behavior has been challenged. “Often, when biologists have measured outcomes in the wild, either helpers weren’t closely enough related, or they could have had their own offspring quite easily, or they didn’t make much difference to the survival of their siblings,” says Andy Radford, also of the University of Bristol and co-author of the study.
Through including the turbulent nature of environments in their analysis, the researchers of this study found that helping behavior evolves much more easily than previously thought. In a highly unpredictable environment, helpers don’t need to be closely related to those they help.
“We realized that help might actually only be of use if the year turns out to be difficult, such as bad weather or not enough food,” explains Seirian Sumner of UCL and co-author of the study. “Helping relatives in bad years can have a huge effect on the number of grandchildren if it means your family does much better than others when times are hard. So, it’s worth siblings hedging their bets and staying at home.”
When times are tough, getting an edge on competing species can make a big difference, even if it makes you less competitive in the good times. Overall, these results could have major implications for our understanding of how cooperation evolves in animals.
Image Credit: Patrick Kennedy