A Short-Term Advantage for Syngamy in the Origin of Eukaryotic Sex: Effects of Cell Fusion on Cell Cycle Duration and Other Effects Related to the Duration of the Cell Cycle—Relationship between Cell Growth Curve and the Optimal Size of the Species, and Circadian Cell Cycle in Photosynthetic Unicellular Organisms
Figure 17
Developmental stages of the eukaryotic cell cycle without the mediation of sex. (a) Primitive stage with phases G1, S, M, a single control point and no growth in the S and M phases. (b) Ditto, with growth in S. The cell size is slightly higher in rich environments than in poor ones. (c) To avoid this problem, a new control point appears, prior to M, which ensures that the cell division size is always optimal. (d) Because of metabolic efficiency, the S phase of the cycle moves to the center, and a new phase, G2, appears.
