海平面升降旋回中的生物响应

通过滇东寒武系筇竹寺阶和曲靖志留纪盆地的层序地层学、生物地层学研究，发现生物与海平面变化之间有一定的规律可寻。（１）物种形态响应：在滇东寒武系筇竹寺阶三叶虫演化序列中，这种响应反映为海平面下降过程有利于形成土著（原地）物种；而海平面上升则导致异地物种的迁入。（２）群落响应：每一个海平面变化旋回都要产生底栖海相群落的重组，形成新的生物组合。（３）种群响应：种群对海平面变化的响应通常表现为种群大小的波动，实质上是种群在不同生存环境中的不同表现。

BIOLOGICAL RESPONSES TO EUSTATIC CYCLES

Through studies of the sequence stratigraphy and biostratigraphy of the Cambrian Qiongzhusian Stage and the Silurian Qujing basin in Yunnan, the author found that there are certain relationships （or called responses） between organisms and eustatic cycles. （1） Morphological response: In the evolutionary sequence of trilobites in the Qiongzhusian Stage this response is manifested by the fact that the process of sea level fall is favorable to the formation of endemic forms, while the sea level rise results in the immigration of allopatric forms. （2） Community response: Each eustatic cycle will result in reorganization of benthic marine communities, forming a new biotic assemblage. （3） Population response: It is usually marked by the fluctuation of the population size, which is in essence interpreted as different manifestions of a population in different habitats.