The chapter contains an excellent summary of the history of genome sizes in bacteria and eukaryotes and a detailed description of both the c-value paradox and the mutation load arguments. The relationship between junk DNA and population size is described.
I was especially pleased to see that the author didn't pull any punches in describing the ENCODE publicity campaign and their false statements about junk DNA.
In 2012, a post-human-genome project called ENCODE, which aims to experimentally identify regions of the human genome that undergo transcription—or are bound by a set of DNA-binding proteins, or undergo chemical changes called epigenetic modifications—came to a stunning conclusion that at least 80% of the human genome is functional and that it was time to sing a requiem for the concept of junk DNA! However, this conclusion, which has been severely criticised since its publication, ignores decades of well-supported arguments from evolutionary biology arising from the c-value paradox, some of which we have described here or will do so shortly; it does not quite explain why this conclusion—if broadly applied to the genomes of other multicellular eukaryotes—would not imply that a fish needs 100 times as much functional DNA as a human; and plays “fast and loose” with the definition of the term ‘function’. While the ENCODE project, a great success in many ways, has provided an invaluable resource for the study of human molecular biology, we can safely ignore its ill-fated conclusion on what fraction of the human genome is functional.