A universal driver of macroevolutionary change in the size of marine phytoplankton over the Cenozoic
A universal driver of macroevolutionary change in the size of marine phytoplankton over the Cenozoic
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DOI：
10.1073/pnas.0709381104
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发表时间：
2007-12-18
影响因子：
11.1
通讯作者：
Falkowski, P. G.
中科院分区：
文献类型：
--
作者：
Finkel, Z. V.;Sebbo, J.;Falkowski, P. G.
浮游植物群落的大小结构强烈地影响着通过食物网的能量转移和海洋中的碳循环。我们确定了甲藻孢囊中值大小的宏观进化轨迹，以与其他浮游生物种群的宏观进化大小变化进行比较。我们发现，甲藻包囊的中位数在新生代期间普遍减小。尽管两个种群的物种多样性具有相反的趋势，但随着时间的推移，硅藻的中位数大小表现出极其相似的模式，这表明宏观进化大小的变化是对选择压力的主动反应，而不是对多样性变化的被动反应。甲藻包囊中值大小的变化与深海温度和表层与深海之间的温度梯度高度相关，表明营养物质可获得性的大小和频率可能在浮游生物细胞大小的宏观进化中起到了选择因素的作用。我们的结果表明，气候，因为它影响海洋分层，是一个普遍的非生物驱动因素，在过去6500万年的地球历史中，它导致了海洋浮游生物群落大小结构的宏观进化变化。
The size structure of phytoplankton assemblages strongly influences energy transfer through the food web and carbon cycling in the ocean. We determined the macroevolutionary trajectory in the median size of dinoflagellate cysts to compare with the macroevolutionary size change in other plankton groups. We found the median size of the dinoflagellate cysts generally decreases through the Cenozoic. Diatoms exhibit an extremely similar pattern in their median size over time, even though species diversity of the two groups has opposing trends, indicating that the macroevolutionary size change is an active response to selection pressure rather than a passive response to changes in diversity. The changes in the median size of dinoflagellate cysts are highly correlated with both deep ocean temperatures and the thermal gradient between the surface and deep waters, indicating the magnitude and frequency of nutrient availability may have acted as a selective factor in the macroevolution of cell size in the plankton. Our results suggest that climate, because it affects stratification in the ocean, is a universal abiotic driver that has been responsible for macroevolutionary changes in the size structure of marine planktonic communities over the past 65 million years of Earth's history.