Collaborative Research: The Role of Choice in Avian Speciation

非技术概述NSF IBN95-07514鸟类物种形成中配偶选择的作用首席研究员南希·泰勒·伯利研究进化过程的科学家们最感兴趣的问题是新物种的形成是如何发生的。物种形成的常见机制包括长时间的种群物理隔离：当种群之间充分隔离以至于几乎不发生迁徙时，种群的特征经常会出现差异。如果隔离持续足够长的时间，结果就是物种形成。然而，即使是偶尔的种群间迁徙，也会导致基因交换，从而防止种群的遗传分化，至少在迁徙的结果是来自不同种群的个体的联合繁殖时是这样。因此，生物体接受出生于不同种群的个体作为配偶的倾向应该影响物种形成的概率和速度。对于具有良好扩散能力的生物来说，种群之间的物理隔离可能很少发生，而出生种群成员的配偶选择可能在物种形成过程中发挥重要作用。本研究通过实验研究了两个种群的长尾雀对出生种群的配偶偏好的发生及其意义。长尾雀是一种原产于澳大利亚北部的小型鸣鸟；尽管它是一种强壮的飞行者，但彼此之间距离较短的自然种群非常独特。初步研究表明，来自一个种群的鸟类拒绝与来自不同种群的鸟类交配。更多的工作将确定这种偏爱出生人口的原因和作用。研究将包括调查鸟类用来识别自己种群中的鸟类的线索；早期的生活经历如何改变鸟类对什么构成自己种群的感知；以及与亲缘关系的偏好在这些种群偏好中的作用。这些实验的结果将与当代生物学科学探索的几个广泛领域相关，包括种群生物学、进化论、生态学和动物行为。研究结果可能有助于我们进一步了解野生动物的圈养繁殖和濒危物种的管理。

Non-technical Summary NSF IBN95-07514 The Role of Mate Choice in Avian Speciation Nancy Tyler Burley, Principal Investigator A question of central interest to scientists studying the process of evolution is how the formation of new species ("speciation") occurs. Common mechanisms of speciation involve physical isolation of populations for long periods of time: when sufficiently isolated such that virtually no migration occurs between populations, populations regularly diverge in their traits. If isolation continues long enough, the result is speciation. Even occasional migration between populations, however, leads to gene exchange that prevents genetic divergence of populations from occurring, at least when the consequence of migration is joint reproduction of individuals derived from different populations. Thus, the tendency of organisms to accept as mates those individuals born in different populations should affect the probability and rate of speciation. For organisms with good powers of dispersal, physical isolation between populations may occur rarely, and mate choice for members of one's natal population could have an important role in speciation processes. This study experimentally investigates the occurrence and significance of mate preferences for natal population in two populations of longtailed finches. The longtailed finch is a small songbird native to northern Australia; although it is a strong flier, natural populations occurring at short distances from one another are highly distinctive. Preliminary work has established that birds from one population refuse to mate with birds from a different population. Additional work will determine the causes and functions of this preference for natal population. Research will include investigation of the cues birds use to recognize birds from their own population; how early life experiences may modify a bird's p erception of what constitutes "its own" population; and the role of preferences for associating with kin in these population preferences. Results of these experiments will be relevant to several broad areas of contemporary scientific exploration in biology, including population biology, evolution, ecology, and animal behavior. Results may be useful in furthering our understanding of captive breeding of wild animals and management of threatened species.