Structural Properties of Genotype-Phenotype Maps: Models, Estimates and Evolution

Genotype-phenotype (GP) maps play a crucial role in evolution, as they set up a connection between the space of genotypes, on which mutations take place, and the space of phenotypes, which is affected by selection. This thesis studies a range of questions surrounding the structural properties of GP maps. In the first part, the origin of a striking structural property shared by GP maps is studied, namely the positive correlation between the robustness and evolvability of phenotypes. By introducing analytically tractable models of GP maps, this positive correlation is shown to emerge from non-local effects of mutations on sequence constraints. Genotypes mapping to the same phenotype are usually connected through one-point mutations and form networks. These networks can be fully connected or fragmented into disjoint components, which are commonly referred to as neutral components (NCs). NCs are the most essential neutral units for populations evolving on the space of genotypes. The second part focuses on the network community structure of NCs in the GP map of RNA secondary structure. In particular, a way to reveal the hierarchical community structure solely from the sequence constraints and composition of the genotypes forming a NC is studied. Further, a way to estimate the community structure from a genotype sample is established, which is applicable if an exhaustive analysis of the NC is not feasible. In the third part, a complete framework to estimate the size and robustness of NCs in the RNA secondary structure GP map is introduced. The framework works with a small genotype sample taken from the NC of interest and facilitates a study of these two essential NC characteristics if an exhaustive analysis is not feasible. In the fourth part, attempts to estimate the evolvability of NCs from genotype samples are discussed. Finally, the fifth part studies the impact of the structural properties of the RNA secondary structure GP map on the evolution of complexity.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2020

Author dc:creator

• Weiß, Marcel

Advisor dc:contributor.advisor

• Ahnert, Sebastian

• Genotype-Phenotype Map
• Evolution
• RNA Secondary Structure
• Neutral Network
• Robustness
• Evolvability

Licence

• https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/dc69611e-7ca3-40bb-a426-8efcd1daf595/download
• https://www.rioxx.net/licenses/all-rights-reserved/

Language dc:language

eng

Author Identifier

0000-0003-1988-2122

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/321353