蚂蚁过着一种严密的、高度发达的组织生活。它们因为力量、组织、团队合作而闻名。但是根据《每日邮报》近日报道，科研人员发现蚂蚁成功的一个关键秘密是它们懂得在工作场所中年龄的重要性。
俄勒冈大学和俄勒冈州立大学的研究人员对中美洲的切叶蚁进行了研究，他们发现，蚁群中年轻和精力充沛的成员被委派去做最艰难的工作——将蚁群收集起来的叶片切成碎片。这些身强力壮的切叶蚁用它们锐利的牙齿做起这种工作来很有效率，但是随着年龄的增长，它们的牙齿也会变得破旧而迟钝。
但是年长的切叶蚁退休后并没有成为蚁群中的废物，它们被赋予了另一种更合适的工作，也就是搬运叶片。像人类一样，这些蚂蚁承认那些年老的成员仍然能够为家族做贡献。
斯科菲尔德博士说：“这项研究证明了社会生活的一个优势，这一点是我们所熟悉的。那些不能做某种特定工作的人们仍然可以为社会做出很大的贡献。”（生物谷Bioon.com）
生物谷推荐原文出处：
Behavioral Ecology and Sociobiology DOI: 10.1007/s00265-010-1098-6Online First?
Leaf-cutter ants with worn mandibles cut half as fast, spend twice the energy, and tend to carry instead of cut
Robert M. S. Schofield, Kristen D. Emmett, Jack C. Niedbala and Michael H. Nesson
Abstract
The importance of mechanical wear in the behavioral ecology and energetics of small organisms is an open question. We investigated wear in leaf-cutter ants, Atta cephalotes, because their cutting technique can be imitated and the leaves are the main energy source for the colony. We found that a razor-sharp (50-nm radius) “V-blade” that cuts leaves between the first and second mandibular teeth was dulled (～10-μm radius) and often nearly worn away on foragers. We found that the force required to cut standard leaves, using mandibles removed from foragers cutting in the wild, varied by a factor of 2.5 with tooth wear, defined as the difference between pupal and actual tooth length. We also found that wear significantly reduced the cutting rate. From the distribution of wear among the cutting foragers, we estimated that the wild colony would have spent 44% less of both energy and time making the observed cuts if the cutters’ mandibles had all been pristine. Finally, wear correlated with behavioral differences—foragers with the most worn 10% of mandibles almost exclusively carried rather than cut. This previously unreported form of task partitioning suggests that eusociality may extend useful lifespans by making it possible to switch tasks as skills decline. We developed a model, assuming that ants do work at a constant rate proportional to their mass, to predict the cutting rate from head width, tooth wear, and force to cut leaves with a scalpel (R?=?0.62), and we used this estimate to argue that the partitioning of cutting and carrying was sub-optimal but better than random. Wear’s strong effect on performance may promote wear-avoiding behavior and wear-resistant mandible composition; it may affect leaf selection and worker lifespan and it raises the possibility that wear is a similarly important constraint for many other small organisms.
Keywords Atta cephalotes - Task allocation - Energetics - Cutting rate - Wear - Task partitioning - Aging
