Buffalo Museum of Science, 1020 Humboldt Parkway, Buffalo, NY, 14211-1293, U.S.A.
McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, 3215 Hull Rd, Gainesville, FL, 32611, U.S.A.
Biol Rev Camb Philos Soc. 2021 Aug;96(4):1160-1185. doi: 10.1111/brv.12696. Epub 2021 Mar 21.
In the traditional biogeographic model, the Galápagos Islands appeared a few million years ago in a sea where no other islands existed and were colonized from areas outside the region. However, recent work has shown that the Galápagos hotspot is 139 million years old (Early Cretaceous), and so groups are likely to have survived at the hotspot by dispersal of populations onto new islands from older ones. This process of metapopulation dynamics means that species can persist indefinitely in an oceanic region, as long as new islands are being produced. Metapopulations can also undergo vicariance into two metapopulations, for example at active island arcs that are rifted by transform faults. We reviewed the geographic relationships of Galápagos groups and found 10 biogeographic patterns that are shared by at least two groups. Each of the patterns coincides spatially with a major tectonic structure; these structures include: the East Pacific Rise; west Pacific and American subduction zones; large igneous plateaus in the Pacific; Alisitos terrane (Baja California), Guerrero terrane (western Mexico); rifting of North and South America; formation of the Caribbean Plateau by the Galápagos hotspot, and its eastward movement; accretion of Galápagos hotspot tracks; Andean uplift; and displacement on the Romeral fault system. All these geological features were active in the Cretaceous, suggesting that geological change at that time caused vicariance in widespread ancestors. The present distributions are explicable if ancestors survived as metapopulations occupying both the Galápagos hotspot and other regions before differentiating, more or less in situ.
在传统的生物地理学模型中，加拉帕戈斯群岛出现在几百万年前的一片没有其他岛屿存在的海域，是从该地区以外的地方殖民而来的。然而，最近的研究表明，加拉帕戈斯热点已有 1.39 亿年的历史（早白垩世），因此，群体很可能通过从较老的岛屿向新岛屿扩散来在热点中幸存下来。这种物种扩散的动态过程意味着，只要有新的岛屿形成，物种就可以在海洋区域无限期地生存下去。物种还可以通过地理隔离形成两个物种，例如在活跃的岛弧中，由于转换断层而分裂。我们回顾了加拉帕戈斯群岛各群体的地理关系，发现至少有两个群体共享 10 种生物地理模式。这些模式中的每一种都与主要的构造结构在空间上重合；这些结构包括：东太平洋隆起；西太平洋和美洲俯冲带；太平洋上的大型火成高原；阿利西托地体（下加利福尼亚），格雷罗地体（墨西哥西部）；北美和南美的裂谷；加拉帕戈斯热点形成的加勒比高原及其向东运动；加拉帕戈斯热点轨迹的增生；安第斯山脉的隆起；以及罗曼尔断层系统的位移。所有这些地质特征在白垩纪都很活跃，这表明当时的地质变化导致了广泛祖先的地理隔离。如果祖先作为占据加拉帕戈斯热点和其他地区的物种扩散种群在分化之前或多或少原地生存，那么目前的分布是可以解释的。
