Do unprofitable prey evolve traits that profitable prey find difficult to exploit?
Do unprofitable prey evolve traits that profitable prey find difficult to exploit?
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DOI：
10.1098/rspb.2005.3229
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发表时间：
2005-11-22
影响因子：
4.7
通讯作者：
Franks, DW
中科院分区：
文献类型：
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作者：
Sherratt, TN;Franks, DW
攻击无利可图的猎物（例如，那些含有有毒化学物质的猎物）通常有明显的图案，与缺乏这些防御的物种相比，它们的移动速度更慢，更可预测。当代理论认为，这些特征已经进化为警告信号，因为它们可以促进捕食者的联想和判别回避学习。然而，目前尚不清楚为什么这些特殊的特征而不是其他特征倾向于在无利可图的猎物中进化。在这里，我们使用一个信号检测模型表明，无利可图的猎物会进化出明显的颜色和图案，部分原因是这些特征在没有密切模仿的情况下很难在有利可图的猎物身上进化出来。这种信号的稳定性是通过对有利可图的猎物不诚实的代价来维持的。事实上，无利可图的猎物有时会进化出一种引人注目的形式来减少模仿寄生，即使这种形式可能更接近模仿。这是第一个允许模仿可能性的警告信号进化的数学模型之一，然而我们的分析表明，它可能提供了一个关于为什么警告信号采取它们所做的形式的一般解释。因此，警告信号和模仿的关系可能比目前认为的更为密切。
Prey that are unprofitable to attack (for example, those containing noxious chemicals) are often conspicuously patterned and move in a slower and more predictable manner than species lacking these defences. Contemporary theories suggest these traits have evolved as warning signals because they can facilitate both associative and discriminative avoidance learning in predators. However, it is unclear why these particular traits and not others have tended to evolve in unprofitable prey. Here we show using a signal detection model that unprofitable prey will evolve conspicuous colours and patterns partly because these characteristics cannot readily evolve in profitable prey without close mimicry. The stability of this signal is maintained through the costs of dishonesty in profitable prey. Indeed, unprofitable prey will sometimes evolve a conspicuous form to reduce mimetic parasitism, even in the unlikely event that this form can be more closely mimicked. This is one of the first mathematical models of the evolution of warning signals to allow for the possibility of mimicry, yet our analyses suggest it may offer a general explanation as to why warning signals take the form that they do. Warning signals and mimicry may therefore be more closely related than is currently supposed.