Hoberg E P
US National Parasite Collection, USDA, Agricultural Research Service, Animal Parasitic Diseases Laboratory, BARC East No. 1180, 10100 Baltimore Avenue, Beltsville, MD, 20705, USA.
Rev Sci Tech. 2010 Aug;29(2):255-72.
The biosphere in evolutionary and ecological time has been structured by episodes of geographic and host colonisation that have determined distributions of complex assemblages of microparasites and macroparasites, including helminths circulating among vertebrates. Biological invasion is an intricate phenomenon often involving 'extra-range dispersal' and establishment of exotic (non-indigenous) species and populations substantially beyond their native range. Invasion may also involve the expansion or shifting of host and geographic distributions of an endemic (indigenous) species or fauna under changing environmental conditions. Invasions result in faunal interchange occurring under influences from both natural and anthropogenic forces where expansion on spatial/temporal continua bridges continents, regions and landscapes. Drivers for invasion are idiosyncratic, multifactorial, interactive, and opportunistic, with a powerful role for historical contingency. The life history patterns of helminths interact with invasion pathways to determine the potential for introduction. Human-mediated events, such as the global expansion of pathogens linked to development of agriculture, domestication of food animals, and European exploration have had a pervasive influence on the distribution of helminths. Globalisation, broad transport networks and environmental perturbation linked to climate change, along with other drivers, have accelerated these processes. A consequence of invasion and establishment of exotic species is that faunal structure will be a mosaic that includes admixtures of indigenous and non-indigenous species and populations; exemplified by helminth faunas among domestic and free-ranging ungulates and a diversity of host-parasite systems among vertebrates. Contemporary mosaics are evident where human-mediated events have brought assemblages of new invaders and relatively old endemic species into sympatry, highlighting interactions at ecotones, particularly those at borderlands between managed and natural ecosystems. Understanding the historical origins and complex components of mosaics is essential in formulating predictions about future responses to environmental change. Powerful tools are available which support the study of invasive species, the most important being systematics and our capacity to accurately identify parasites and to define evolutionary and biogeographic history. Faunal baselines derived from arrays of biological specimens, integrated surveys and informatics are a permanent record of the biosphere when archived in museum collections. The absence of comprehensive taxonomic inventories of parasites, including molecular-genetic data, limits our ability to recognise the introduction of non-indigenous parasites, and to document patterns of expansion for local faunas under a regime of environmental perturbation.
在进化和生态时间尺度上，生物圈是由地理和宿主定殖事件构建而成的，这些事件决定了包括在脊椎动物间传播的蠕虫在内的微寄生虫和大寄生虫复杂组合的分布。生物入侵是一种复杂的现象，通常涉及“超范围扩散”以及外来（非本土）物种和种群在其原生范围之外的大量定殖。入侵还可能涉及在不断变化的环境条件下，本地（本土）物种或动物群的宿主和地理分布的扩展或转移。入侵导致动物区系在自然和人为力量的影响下发生交换，在空间/时间连续体上的扩展跨越了各大洲、地区和景观。入侵的驱动因素具有独特性、多因素性、交互性和机会性，历史偶然性起着重要作用。蠕虫的生活史模式与入侵途径相互作用，决定引入的可能性。人类介导的事件，如与农业发展、食用动物驯化以及欧洲探索相关的病原体全球扩张，对蠕虫的分布产生了广泛影响。全球化、广泛的运输网络以及与气候变化相关的环境扰动，连同其他驱动因素，加速了这些进程。外来物种入侵和定殖的一个后果是，动物区系结构将成为一个镶嵌体，其中包括本土和非本土物种及种群的混合；家养和自由放养有蹄类动物的蠕虫动物区系以及脊椎动物中多种多样的宿主 - 寄生虫系统就是例证。在人类介导的事件使新入侵者组合与相对古老的本地物种同域分布的地方，当代镶嵌体很明显，这突出了生态交错带的相互作用，特别是在管理生态系统和自然生态系统之间的边界地带。了解镶嵌体的历史起源和复杂组成部分对于预测未来对环境变化的反应至关重要。现已有强大的工具支持对入侵物种的研究，其中最重要的是系统分类学以及我们准确识别寄生虫并界定进化和生物地理历史的能力。从生物标本阵列、综合调查和信息学中得出的动物区系基线，当存档于博物馆藏品中时，是生物圈的永久记录。缺乏包括分子遗传学数据在内的寄生虫综合分类清单，限制了我们识别非本土寄生虫引入以及记录在环境扰动情况下本地动物区系扩展模式的能力。
