Research Abstract

働かないワーカーは社会性昆虫のコロニーの長期的存続に必須である  OPEN ブックマーク

Lazy workers are necessary for long-term sustainability in insect societies

2016年2月16日 Scientific Reports 6 : 20846 doi: 10.1038/srep20846 (2016)


Eisuke Hasegawa, Yasunori Ishii, Koichiro Tada, Kazuya Kobayashi & Jin Yoshimura

Corresponding Authors

長谷川 英祐
北海道大学大学院 農学研究院 動物生態学研究

吉村 仁
静岡大学 学術院工学領域 数理システム工学系列

Optimality theory predicts the maximization of productivity in social insect colonies, but many inactive workers are found in ant colonies. Indeed, the low short-term productivity of ant colonies is often the consequence of high variation among workers in the threshold to respond to task-related stimuli. Why is such an inefficient strategy among colonies maintained by natural selection? Here, we show that inactive workers are necessary for the long-term sustainability of a colony. Our simulation shows that colonies with variable thresholds persist longer than those with invariable thresholds because inactive workers perform the critical function of replacing active workers when they become fatigued. Evidence of the replacement of active workers by inactive workers has been found in ant colonies. Thus, the presence of inactive workers increases the long-term persistence of the colony at the expense of decreasing short-term productivity. Inactive workers may represent a bet-hedging strategy in response to environmental stochasticity.