Genome size (total base pairs) and gene number do not scale proportionally across the evolutionary tree, and neither correlates with organismal complexity, indicating that genome content beyond protein-coding sequence — introns, untranslated regions, and repetitive DNA — accounts for most genomic expansion. A gene is best defined functionally as a segment of DNA expressed to yield any functional product (protein, rRNA, tRNA, or other RNA), not merely one transcribed into messenger RNA. This belongs to molecular biology/genomics, relating genome architecture (coding vs. non-coding fractions, intron/exon structure, repetitive element classes) to the broader disciplines of evolutionary biology and gene regulation.
Genome size (total base pairs) and gene number do not scale proportionally across the evolutionary tree, and neither correlates with organismal complexity, indicating that genome content beyond prote…