A transcription factor gene regulatory network is much more likely to arise through gene duplication and upstream transposon insertions than by random mutation

A transcription factor gene regulatory network is much more likely to arise through gene duplication and upstream transposon insertions than by random mutation - especially in plants and animals, which have long generation times, low population sizes, and proofreading processes to suppress point mutations, while also facilitating gene duplication via sexual recombination. Eukaryotes have also evolved chromatin accessibility restrictions to control not just expression but evolvability of DNA regions. Point mutations on their own don't seem like a plausible mechanism for the level of plasticity exhibited in plant and animal genomes.