Evolution of Eukaryotes - Essay Example

Eukaryotic cells are believed to have evolved from certain organelles, mitochondria and chloroplasts, in the prokaryotic cells that were residing in the cytoplasm of a bigger host cell. This hypothesis by Lynn Margulis is known as endosymbiont theory since it expounds on how a single “composite” cell of higher complexity “evolved from more separate simpler cells living in a symbiotic relationship with one another” (Karp, 2009, p.25). The evolution of eukaryotic cells begins in step 1; a large anaerobic which is a heterotrophic prokaryote taking in a small aerobic prokaryote. In step 2, the aerobic endosymbiont evolves into a mitochondrion. This step is followed by step 3 in which a portion of the plasma membrane invaginates in the process of evolving into a nuclear envelope as well as associated endoplasmic reticulum. Step 3 results in a primitive eukaryote in step 4 that gives rise to two main groups of eukaryotes. Read More