School of Biosciences, Cardiff University, Cardiff, CF10 3AX, U.K.
Faculty of Technical and Human Science, Department of Horticulture, Sapientia Hungarian University of Transylvania, 540485, Tirgu-Mures, Romania.
Biol Rev Camb Philos Soc. 2018 Feb;93(1):642-657. doi: 10.1111/brv.12361. Epub 2017 Aug 23.
Debate still continues around the definition of generalism and specialism in nature. To some, generalism is equated solely with polyphagy, but this cannot be readily divorced from other essential biological factors, such as morphology, behaviour, genetics, biochemistry, chemistry and ecology, including chemical ecology. Viewed in this light, and accepting that when living organisms evolve to fill new ecological-evolutionary niches, this is the primal act of specialisation, then perhaps all living organisms are specialist in the broadest sense. To illustrate the levels of specialisation that may be found in a group of animals, we here provide an overview of those displayed by a subfamily of hemipteran insects, the Aphididae, which comprises some 1600 species/subspecies in Europe alone and whose members are specialised in a variety of lifestyle traits. These include life cycle, host adaptation, dispersal and migration, associations with bacterial symbionts (in turn related to host adaptation and resistance to hymenopterous wasp parasitoids), mutualisms with ants, and resistance to insecticides. As with polyphagy, these traits cannot easily be separated from one another, but rather, are interconnected, often highly so, which makes the Aphididae a fascinating animal group to study, providing an informative, perhaps unique, model to illustrate the complexities of defining generalism versus specialism.
关于广义论和狭义论的本质，人们仍在争论不休。在一些人看来，广义论仅等同于杂食性，但这不能轻易脱离其他基本的生物学因素，如形态、行为、遗传学、生物化学、化学和生态学，包括化学生态学。从这个角度来看，并承认当生物体进化以填补新的生态进化小生境时，这是专门化的最初行为，那么也许所有生物体在最广泛的意义上都是专家。为了说明在一组动物中可能发现的专业化程度，我们在此概述了半翅目昆虫蚜科的一个亚科所表现出的专业化程度，仅在欧洲就有 1600 种/亚种，其成员在各种生活方式特征上都具有专业化。这些特征包括生命周期、宿主适应性、扩散和迁移、与细菌共生体的联系（进而与宿主适应性和对膜翅目黄蜂寄生蜂的抗性相关）、与蚂蚁的互惠关系以及对杀虫剂的抗性。与杂食性一样，这些特征不容易彼此分离，而是相互关联的，通常是高度相关的，这使得蚜科成为一个引人入胜的动物群体，为阐明广义论和狭义论的复杂性提供了一个信息丰富的、也许是独特的模型。
