元古宙多细胞真核藻类起源与早期演化

Origin and Early Evolution of Multicellular Eukaryotic Algae in the Proterozoic Eon

在地球生物圈,多细胞真核藻类是海洋和湖泊等水生生态系统中重要的初级生产者。然而,在地球早期历史中初级生产者以原核生物为主体,这一主导地位的转变发生时间与具体过程还需探索。元古宙地层产出了众多真核生物的早期化石记录,见证了包括多细胞真核藻类在内的真核生物主要类群的起源与早期演化过程。聚焦于元古宙的多细胞真核藻类演化过程,系统梳理该时期绿藻和红藻等类群的重要化石记录及其环境背景,并阐述它们的起源与早期演化的时间框架:古—中元古代是多细胞真核藻类的萌芽期;新元古代拉伸纪是多细胞真核藻类初步崛起、以多核体藻类为主的时代;埃迪卡拉纪多细胞真核藻类发生了生态上的适应性辐射。

In modern Earth's biosphere,eukaryotic algae are important primary producers in aquatic ecosystems such as oceans and lakes.However,in the early history of the Earth,prokaryotes are dominant primary producers.The timing and process of the ecological rise of eukaryotic algae relative to prokaryotes need further discussion.There are abundant fossils of early eukaryotes in Proterozoic successions,which witnessed the origin and early evolution of major groups of eukaryotes,including multicellular eukaryotic algae.This paper focuses on the evolution of multicellular algae in the Proterozoic Eon,critically reviews representative fossils of multicellular alga clades,including green algae and red algae,and their environmental backgrounds during this period,and tries to reconstruct the tempos of their origin and early evolution.The Paleo-Mesoproterozoic is the embryonic period of multicellular algae;the Tonian of the Neoproterozoic Era is a period when multicellular algae had an initial ecological rise,represented by multinucleated algae or coenocytic algae;and the subsequent Ediacaran witnessed an ecological adaptive radiation of multicellular algae.