An evolutionary perspective on caching by corvids
An evolutionary perspective on caching by corvids
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DOI：
10.1098/rspb.2005.3350
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发表时间：
2006-02-22
影响因子：
4.7
通讯作者：
Clayton, NS
中科院分区：
文献类型：
--
作者：
de Kort, SR;Clayton, NS
在食物缓存文献中的一个主要发现是，囤积倾向的物种差异与缓存行为的适应程度的物种差异呈正相关，如空间记忆任务和海马体积的性能。然而，也有不符合这一模式的例子。我们认为，这些例子可以更好地理解考虑物种之间的系统发育相关性。我们重建祖先的状态缓存行为的corvids和评估时，缓存行为的过渡发生在corvid的cordogeny。我们的分析表明，所有鸦类的共同祖先是一个中等的印章。这一结果表明，鸦遵循双向的进化轨迹，缓存是次要的两次丢失，至少有两个独立的过渡，从中度到专门的缓存。因此，这两个群体中专门化贮藏者的独立进化必然是趋同进化的一个例子。这是由以下事实来说明的：专门的缓存器显示出结构上不同的适应性，为强烈的缓存提供相同的功能，例如不同的袋子来运输食物。最后，我们认为，趋同进化可能导致适应的记忆和海马体，服务相同的功能，但不同的设计，这些不同的适应可能解释的例子，不适合的模式预测的自适应专业化假说。
A principal finding in the food-caching literature is that species differences in hoarding propensity are positively correlated with species differences in degree of adaptations to caching behaviour, such as performance on spatial memory tasks and hippocampal volume. However, there are examples that do not fit this pattern. We argue that these examples can be better understood by considering the phylogenetic relatedness between species. We reconstruct the ancestral state for caching behaviour in corvids and assess when transitions in caching behaviour occurred within the corvid phylogeny. Our analysis shows that the common ancestor of all corvids was a moderate cachet. This result suggests that corvids followed a bi-directional evolutionary trajectory in which caching was secondarily lost twice and there were at least two independent transitions from moderate to specialized caching. The independent evolution of specialized cachers in the two groups must, therefore, be a case of convergent evolution. This is exemplified by the fact that specialized cachers show structurally different adaptations serving the same function to intense caching, such as different pouches to transport food. Finally, we argue that convergent evolution may have led to adaptations in memory and hippocampus that serve the same function but differ in design, and that these different adaptations may explain the examples that do not fit the pattern predicted by the adaptive specialization hypothesis.