The ocean depths would act as the refugia 海洋的深水处扮演起生物避难所的角色。
2.
When the climate improves and the forest expands , all the new species that have evolved in the refugia mix 当气候有所好转、森林规模扩大的时候，所有的那些在避难所里完成进化的新物种就开始互相混合。
3.
Abstract : biological invasions are a continuous feature of a non - equilibrium world , ever more so as a result of accidental and deliberate introductions by mankind . while many of these introductions are apparently harmless , others have significant consequences for organisms native to the invaded range , and entire communities may be affected . here we provide a survey of common models of range expansion , and outline the consequences these models have for patterns in genetic diversity and population structure . we describe how patterns of genetic diversity at a range of markers can be used to infer invasion routes , and to reveal the roles of selection and drift in shaping population genetic patterns that accompany range expansion . we summarise a growing range of population genetic techniques that allow large changes in population size ( bottlenecks and population expansions ) to be inferred over a range of timescales . finally , we illustrate some of the approaches described using data for a suite of invasions by oak gallwasps ( hymenoptera , cynipidae , cynipini ) in europe . we show that over timescales ranging from 500 10000 years , allele frequency data for polymorphic allozymes reveal ( a ) a consistent loss of genetic diversity along invasion routes , confirming the role of glacial refugia as centres of genetic diversity over these timescales , and ( b ) that populations in the invaded range are more subdivided genetically than those in the native range of each species . this spatial variation in population structure may be the result of variation in the patchiness of resources exploited by gallwasps , particularly host oak plants 文摘:生物入侵是不均衡世界的一个永恒话题,尤其是当人类有意或无意地引入物种后.很多引入显然是无害的,但另外一些则有着严重的后果,会给入侵地的生物以至于整个生物群落造成影响.本文总结了分布区扩张的常见模式,概述了它们对遗传多样性和种群结构式样所造成的影响.描述了如何根据以一批遗传标记所得到的遗传多样性式样来推断入侵途径,来揭示伴随扩张选择和漂变在形成种群遗传样式中的作用.本文对日益增多的群体遗传学方法进行了总结,这些技术可以用来在不同的时间尺度上推断种群规模所发生的巨大变化(瓶颈效应及种群扩张) .最后,我们以欧洲栎瘿蜂(膜翅目,瘿蜂科,瘿蜂族)一系列入侵的数据为例对一些方法进行了说明.从500 10000年的时间尺度上,多态的等位酶位点上等位基因频率的数据表明: 1 )遗传多样性沿入侵路线呈不断下降的趋势,支持了冰河期避难所作为遗传多样性中心的作用; 2 )入侵地区的种群与该物种原产地的种群相比,遗传上的分化更为强烈.这种种群结构在空间上的变异可能是被栎瘿蜂开发的资源尤其是栎树寄主在斑块上出现变异的反映
