鸟类手指同源问题是进化生物学研究领域最具争论性的问题之一。近年来，包括古生物学家和发育生物学家在内的研究者在《自然》和《科学》等杂志上发表了一系列论文，对这一问题展开了新一轮的激烈讨论。2013年6月17日出版的《当代生物学》杂志上，刊登了中国科学院古脊椎动物与古人类研究所徐星研究员和美国国立卫生研究院(NIH)癌症与发育生物学实验室的S. Mackem博士的综述论文，全面回顾了这一争论的原因，比较了各种不同的假说，并提出了未来的研究方向。
在这篇题为“追寻鸟类手指演化”的论文中，徐星和S. Mackem比较了几种确定同源结构的常用标准，评价了这几种标准的优缺点，重点介绍了鸟类手指演化过程中的复杂性，强调了同源异型机制在鸟类手指演化过程中的作用。这一研究是徐星课题组用整合的方法，结合古生物学和发育生物学资料来解释重要结构演化的一个新成果。
《当代生物学》Current Biology是生物学领域一个具有重要影响的杂志（影响因子超过10），刊登包括演化生物学在内的各类生物学文章。（生物谷Bioon.com）
doi:10.1016/j.cub.2013.04.071
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Tracing the Evolution of Avian Wing Digits
Xing Xu, Susan Mackem
It is widely accepted that birds are a subgroup of dinosaurs, but there is an apparent conflict: modern birds have been thought to possess only the middle three fingers (digits II-III-IV) of an idealized five-digit tetrapod hand based on embryological data, but their Mesozoic tetanuran dinosaur ancestors are considered to have the first three digits (I-II-III) based on fossil evidence. How could such an evolutionary quirk arise? Various hypotheses have been proposed to resolve this paradox. Adding to the confusion, some recent developmental studies support a I-II-III designation for avian wing digits whereas some recent paleontological data are consistent with a II-III-IV identification of the Mesozoic tetanuran digits. A comprehensive analysis of both paleontological and developmental data suggests that the evolution of the avian wing digits may have been driven by homeotic transformations of digit identity, which are more likely to have occurred in a partial and piecemeal manner. Additionally, recent genetic studies in mouse models showing plausible mechanisms for central digit loss invite consideration of new alternative possibilities (I-II-IV or I-III-IV) for the homologies of avian wing digits. While much progress has been made, some advances point to the complexity of the problem and a final resolution to this ongoing debate demands additional work from both paleontological and developmental perspectives, which will surely yield new insights on mechanisms of evolutionary adaptation.
