Darwin's finches prove a mechanism for the rapid formation of new species Darwin's finches, a group of 18 species endemic to the Galápagos archipelago, are a classic example of adaptive radiation—the process whereby a single ancestral species multiplies in number to produce divergent species, often in rapid succession (1). These birds are evolutionary biologists' most celebrated example of natural selection in action. On page 224 of this issue, Lamichhaney et al. (2) have succeeded in observing a process even more elusive than natural selection—the formation of a new species (speciation). Because speciation typically takes place on time scales that are too long for direct human observation, before now it was only in organisms with very fast generation times, such as viruses and bacteria, that scientists had directly observed this process [for example, (3)]. Lamichhaney et al. show through direct observation and DNA sequencing that new species can form very rapidly: within three generations. The key, in this case, is hybridization between different species.

中文翻译：

---

不可能的大鸟

达尔文雀类证明了快速形成新物种的机制 达尔文雀类是加拉帕戈斯群岛特有的 18 种物种，是适应性辐射的典型例子——单个祖先物种在数量上繁殖以产生不同物种的过程，通常快速连续（1）。这些鸟类是进化生物学家最著名的自然选择实例。在本期第 224 页，Lamichhaney 等人。(2) 成功地观察到一个比自然选择更难以捉摸的过程——新物种的形成（物种形成）。因为物种形成通常发生在人类直接观察太长的时间尺度上，所以在此之前，它只发生在具有极快世代时间的生物体中，例如病毒和细菌，科学家们直接观察到了这个过程[例如，(3)]。拉米哈尼等人。通过直接观察和 DNA 测序表明，新物种可以非常迅速地形成：在三代之内。在这种情况下，关键是不同物种之间的杂交。