Maier U G, Hofmann C J, Sitte P
Lehrstuhl für Pflanzensystematik der Universität, Bayreuth.
Naturwissenschaften. 1996 Mar;83(3):103-12.
Life has existed on earth for some 4 x 10(9) years. During most of this time, evolution took place at the level of cell evolution. The cells of presently existing organisms belong to two fundamentally different cell types, protocytes (of bacteria and archaea) and eucytes (of eukarya). Thanks to molecular phylogenetics, the path of evolution can now be traced back to its very beginnings, although the picture may be blurred by repeated horizontal gene transfer. A symbiogenetic origin of plastids and mitochondria is now very well documented, and it is being discussed also for some other constituents of eucytes, including even the cells nucleus. It could be demonstrated that not only did bacterial cells become incorporated into protoeucytes and transformed into organelles of their respective hosts, but also that endocytic eucytes have apparently been transformed to complex organelles by coevolution with host cells.
生命在地球上已经存在了约4×10⁹年。在这段时间的大部分时间里，进化发生在细胞进化层面。目前现存生物的细胞属于两种根本不同的细胞类型，即原核细胞（细菌和古菌的细胞）和真核细胞（真核生物的细胞）。多亏了分子系统发育学，现在可以将进化路径追溯到其最初阶段，尽管由于反复的水平基因转移，情况可能会有些模糊。现在有充分的文献证明质体和线粒体起源于共生，并且也在讨论真核细胞的其他一些组成部分，甚至包括细胞核。可以证明，不仅细菌细胞被整合到原始真核细胞中并转化为各自宿主的细胞器，而且内吞真核细胞显然也通过与宿主细胞的共同进化而转化为复杂的细胞器。
