Department of Neurobiology and Cognition Research, University of Vienna, 1090 Vienna, Austria.
Philos Trans R Soc Lond B Biol Sci. 2010 Apr 12;365(1543):1099-109. doi: 10.1098/rstb.2009.0291.
Darwin's finches are a classic example of adaptive radiation. The ecological diversity of the Galápagos in part explains that radiation, but the fact that other founder species did not radiate suggests that other factors are also important. One hypothesis attempting to identify the extra factor is the flexible stem hypothesis, connecting individual adaptability to species richness. According to this hypothesis, the ancestral finches were flexible and therefore able to adapt to the new and harsh environment they encountered by exploiting new food types and developing new foraging techniques. Phenotypic variation was initially mediated by learning, but genetic accommodation entrenched differences and supplemented them with morphological adaptations. This process subsequently led to diversification and speciation of the Darwin's finches. Their current behaviour is consistent with this hypothesis as these birds use unusual resources by extraordinary means. In this paper, we identify cognitive capacities on which flexibility and innovation depend. The flexible stem hypothesis predicts that we will find high levels of these capacities in all species of Darwin's finches (not just those using innovative techniques). Here, we test that prediction, and find that while most of our data are in line with the flexible stem hypothesis, some are in tension with it.
达尔文雀是适应性辐射的经典范例。加拉帕戈斯群岛的生态多样性在一定程度上解释了这种辐射现象，但其他创始物种没有辐射的事实表明，其他因素也很重要。一个试图确定额外因素的假设是灵活茎假说，它将个体适应性与物种丰富度联系起来。根据这个假设，祖先的雀鸟具有灵活性，因此能够通过利用新的食物类型和开发新的觅食技术，适应它们所遇到的新的、恶劣的环境。表型变异最初是通过学习来调节的，但遗传适应使差异根深蒂固，并通过形态适应来补充它们。这个过程随后导致了达尔文雀的多样化和物种形成。它们目前的行为与这个假说一致，因为这些鸟类通过非凡的手段利用不寻常的资源。在本文中，我们确定了灵活性和创新性所依赖的认知能力。灵活茎假说预测，我们将在所有达尔文雀物种（不仅仅是那些使用创新技术的物种）中发现这些能力的高水平。在这里，我们检验了这个预测，发现虽然我们的大部分数据与灵活茎假说一致，但有些数据与它存在冲突。
