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Genetics
Whole Genome Duplication
The evolutionary events where entire chromosome sets doubled - two occurred at vertebrate origin, and a third specifically in ray-finned fish.
System: Reproductive Level: Advanced Discipline: Cellular
📖 Overview
Whole genome duplications reshape lineages. Two duplication events at the base of vertebrates set the stage for the tetrapod radiation. A third duplication in ray-finned fish (~350 million years ago) laid the genomic foundation for the astonishing diversification of teleosts to 30,000+ species. Salmon and other salmonids added a fourth, more recent duplication - explaining why they carry 3x the genes of humans.
✨ Fun Fact
A salmon has roughly 90,000 protein-coding genes to a human's 30,000 - a consequence of stacked genome duplications preserved through Salmonidae evolutionary history.