Price Jonathan P, Clague David A
Graduate Group in Geography, University of California, Davis, 1 Shields Avenue, Davis, CA 95616, USA.
Proc Biol Sci. 2002 Dec 7;269(1508):2429-35. doi: 10.1098/rspb.2002.2175.
This study quantifies long-term landscape changes in the Hawaiian archipelago relating to dispersal, speciation and extinction. Accounting for volcano growth, subsidence and erosion, we modelled the elevations of islands at time intervals of 0.5 Myr for the last 32 Myr; we also assessed the variation in the spacing of volcanoes during this period. The size, spacing and total number of volcanic islands have varied greatly over time, with the current landscape of large, closely spaced islands preceded by a period with smaller, more distantly spaced islands. Considering associated changes in rates of dispersal and speciation, much of the present species pool is probably the result of recent colonization from outside the archipelago and divergence within contemporary islands, with limited dispersal from older islands. This view is in accordance with abundant phylogenetic studies of Hawaiian organisms that estimate the timing of colonization and divergence within the archipelago. Twelve out of 15 multi-species lineages have diverged within the lifetime of the current high islands (last 5 Myr). Three of these, and an additional seven (mostly single-species) lineages, have colonized the archipelago within this period. The timing of colonization of other lineages remains uncertain.
本研究量化了夏威夷群岛与扩散、物种形成和灭绝相关的长期景观变化。考虑到火山生长、沉降和侵蚀，我们对过去3200万年中每隔0.5百万年的岛屿海拔进行了建模；我们还评估了这一时期火山间距的变化。火山岛的大小、间距和总数随时间发生了很大变化，当前大且间距紧密的岛屿景观之前是一个岛屿较小、间距更远的时期。考虑到扩散和物种形成速率的相关变化，目前的许多物种库可能是近期从群岛外部殖民以及当代岛屿内部分化的结果，来自较古老岛屿的扩散有限。这一观点与大量关于夏威夷生物的系统发育研究一致，这些研究估计了群岛内殖民和分化的时间。15个多物种谱系中有12个在当前高岛的存在期内（过去500万年）发生了分化。其中3个谱系，以及另外7个（大多为单物种）谱系，在这一时期内殖民了该群岛。其他谱系的殖民时间仍不确定。
