Chapter 13

Chapter 13: Robustness and evolvability of biological systems #

Consider a genotype space of the peptide of length 25. Assume the edges to be the protein evolved by the change in single amino acid.

  1. What is the size of the genotype space? (If the answer is \( 2.4×10^{41} \) , enter your answer as 2e41) Ans: 3e32

  2. What is the degree of any genotype in the genotype space? Ans: 475

  3. Choose the genotype neighbours of \( Ala_{23}-Gly_{2} \) in the given genotype space
    a. \( Glu-Ala_{21}-Gly_{3} \)
    b. \( GLu-Ala_{22}-Gly_{2} \)
    c. \( Ala_{22}-Ser-Gly-Gly \)
    d. \( Ala_{15}-Met-Ala_{7}-Gly_{2} \)
    e. \( Ala_{21}-Gly_{4} \)
    Ans: b, c, d

  4. Which of the following statements are true about robustness and evolvability?
    a. The phenotype robustness and phenotype evolvability are typically positively correlated
    b. The phenotype robustness and phenotype evolvability are typically negatively correlated
    c. The average genotype degree of the neutral network is directly proportional to the phenotype robustness
    d. Robust phenotypes exhibit higher evolvability
    Ans: a, c, d

  5. Consider two neutral networks A and B having equal number of nodes. Network B has more connected components than Network A, which comprises a single connected component. Which of the following statements is/are true?
    a. Phenotype corresponding to Network A likely has higher evolvability
    b. Phenotype corresponding to Network B likely has higher evolvability
    c. Phenotype corresponding to Network A has higher robustness
    d. Phenotype corresponding to Network B has higher robustness
    e. Cannot be concluded with the above information
    Ans: a, c