Alternative Endosymbiosis

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Alternative Approach in the Evolution of Endosymbiosis

In the article, “The Birth of Complex Cells,” Christian de Duve proposed the theory of cell evolution in which prokaryotes evolved into eukaryotes through a complex process of endosymbiosis. In this theory, de Duve proposes that the beginning step to the evolution is that the prokaryote loses its cell wall which increases its ability to grow in size as well as its ability to change shape. It would then be able to expand and fold its membrane, simultaneously increasing its surface area for more intake of food and nutrients. Further, de Duve explains that this enhanced ability of taking in nutrients through the membrane would boost their survival because it would then be easier for the cells to catch and process their food. Prokaryotes would now digest their food inside the cell instead of outside the cell. The cells would now be able to perform features that are associated with phagocytosis where the cell possesses the ability to engulf objects located outside the membrane by using a process similar to endocytosis. The phagocyte would eat smaller prokaryotes which would then form into endosymbionts of the cell to perform specific functions that the cell needed in order to survive in the environment in which it was living. The phagocytes, for example, incorporated endosymbionts similar to mitochondria and peroxisomes. The development of the mitochondria and peroxisomes then could form the precursors of plastids which would allow the cell to perform photosynthesis. Finally, through a long process, the DNA and proteins from the original phagocyte were transferred and migrated into the endosymbionts to transform them into cell organelles, from “prisoner to slave” as de Duve wrote. They would now be part of the cell itself and be considered one entire eukaryote. The process of incorporating the mitochondria, plastid, and the peroxisomes from other cells is supported by the ar...