The origin of biological homochirality along with the origin of life
PAT = 0 (i.e., template-directed synthesis is disabled); PRL = 1×10−6, PNDE = 1×10−5, FCSS = 0. The extending rate for a monomer, dimmer, trimmer and longer polymer is represented as R1-mer, R2-mer, R3-mer, and Rn-mer, respectively (PRL is multiplied by one of such rates in the corresponding situation). Dotted line (control): Rn-mer = R3-mer = R2-mer = R1-mer (the dotted line actually overlaps with the dashed-dotted line, which are both at the level of ee = 0); dash-dotted line: Rn-mer = R3-mer = 5×R2-mer = 50×R1-mer (the primer effect is not sufficiently strong to induce the chirality-deviation); dashed line: Rn-mer = R3-mer = 10×R2-mer = 100×R1-mer (the primer effect is strong enough to induce a chirality-deviation); solid line: Rn-mer = R3-mer = 20×R2-mer = 200×R1-mer (the primer effect is so strong as to induce a significant chirality-deviation). The evolution of RNA’s chain-length distributions for the solid-line case is displayed below (the chains longer than 20 nt are not displayed). Note that the prevailing of D-RNA (instead of L-RNA) as shown in the solid-line case and the dashed-line case is merely by chance.