Cuckoos versus hosts in insects and birds: adaptations, counter-adaptations and outcomes
Cuckoos versus hosts in insects and birds: adaptations, counter-adaptations and outcomes
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DOI：
10.1111/j.1469-185x.2010.00173.x
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发表时间：
2011-11-01
影响因子：
10
通讯作者：
Langmore, Naomi E.
中科院分区：
文献类型：
--
作者：
Kilner, Rebecca M.;Langmore, Naomi E.
鸟类父母和社会昆虫群体是种间育雏寄生虫欺骗的受害者，欺骗者通过将它们留在另一个物种的托儿所来获得对它们依赖的后代的昂贵照顾。鸟类和昆虫保护自己免受亲卵寄生虫的攻击;它们的防御反过来选择寄生虫的反策略，从而启动双方之间的对抗性共同进化。尽管它们在分类学上存在相当大的差异，但在这里，我们发现了昆虫和鸟类中的育雏寄生虫与宿主之间的共同进化方式有着惊人的相似之处。首先，我们确定五种类型的共同进化的军备竞赛的实证文献，这是共同的两个系统。这些是：（a）武器和军械库的定向共同进化;（B）寄生虫的隐秘性，被宿主暴露寄生虫的策略所抵消;（c）专门寄生虫模仿宿主，宿主通过多样化其遗传特征而逃脱;（d）多面手寄生虫模仿宿主，宿主通过偏爱迫使寄生虫专门化的特征而逃脱;以及（e）寄生虫使用密码来逃避宿主的识别，然后宿主简化它们的签名以使寄生虫更容易检测。军备竞赛a和c在关于共同进化的理论文献中得到了很好的描述，但其他类型的军备竞赛很少或根本没有得到正式的理论关注。经验研究表明，寄生虫通常会逃避宿主的防御并成功地寄生在巢穴中，因此宿主注定会在B和e的军备竞赛中输给寄生虫。然而，当共同进化的轨迹遵循军备竞赛a、c或d时，宿主可能会赢。接下来，我们展示了宿主共同进化军备竞赛的四个共同结果。这些是：（1）成功抵抗;（2）防御组合（或多个抗性系）的进化;（3）对寄生虫的接受;以及（4）对寄生虫的耐受性。特定的结果并不取决于之前的军备竞赛的类型，而是更多地取决于宿主或寄生虫是否控制共同进化的轨迹：耐受性是寄生虫对宿主造成的结果，而其他三种结果更多地取决于宿主物种固有的特性。最后，我们的审查强调了相当大的种间变异的复杂性和深度的主机防御组合。这种变化是适应性的还是仅仅反映了进化滞后还不清楚。我们提出了一个适应性的解释，它集中在两个相反的过程的相对强度：战略促进，其中一条线的主机防御促进另一种形式的阻力的演变，和战略阻止，其中一条线的防御可能会放松对另一个选择如此完全，它会导致它衰减。我们认为，当战略便利超过战略阻止，主机将拥有复杂的防御组合，我们确定选择性的条件下，这是可能的情况。
Avian parents and social insect colonies are victimized by interspecific brood parasites cheats that procure costly care for their dependent offspring by leaving them in another species' nursery. Birds and insects defend themselves from attack by brood parasites; their defences in turn select counter-strategies in the parasite, thus setting in motion antagonistic co-evolution between the two parties. Despite their considerable taxonomic disparity, here we show striking parallels in the way that co-evolution between brood parasites and their hosts proceeds in insects and birds. First, we identify five types of co-evolutionary arms race from the empirical literature, which are common to both systems. These are: (a) directional co-evolution of weaponry and armoury; (b) furtiveness in the parasite countered by strategies in the host to expose the parasite; (c) specialist parasites mimicking hosts who escape by diversifying their genetic signatures; (d) generalist parasites mimicking hosts who escape by favouring signatures that force specialization in the parasite; and (e) parasites using crypsis to evade recognition by hosts who then simplify their signatures to make the parasite more detectable. Arms races a and c are well characterized in the theoretical literature on co-evolution, but the other types have received little or no formal theoretical attention. Empirical work suggests that hosts are doomed to lose arms races b and e to the parasite, in the sense that parasites typically evade host defences and successfully parasitize the nest. Nevertheless hosts may win when the co-evolutionary trajectory follows arms race a, c or d. Next, we show that there are four common outcomes of the co-evolutionary arms race for hosts. These are: (1) successful resistance; (2) the evolution of defence portfolios (or multiple lines of resistance); (3) acceptance of the parasite; and (4) tolerance of the parasite. The particular outcome is not determined by the type of preceding arms race but depends more on whether hosts or parasites control the co-evolutionary trajectory: tolerance is an outcome that parasites inflict on hosts, whereas the other three outcomes are more dependent on properties intrinsic to the host species. Finally, our review highlights considerable interspecific variation in the complexity and depth of host defence portfolios. Whether this variation is adaptive or merely reflects evolutionary lag is unclear. We propose an adaptive explanation, which centres on the relative strength of two opposing processes: strategy-facilitation, in which one line of host defence promotes the evolution of another form of resistance, and strategy-blocking, in which one line of defence may relax selection on another so completely that it causes it to decay. We suggest that when strategy-facilitation outweighs strategy-blocking, hosts will possess complex defence portfolios and we identify selective conditions in which this is likely to be the case.