Viruses Are by Far the Most Genetically Variable and Biodiverse Group of Organisms, Generate High Diversity in Cellular Organisms, and Are Key Drivers of Major Adaptive Macroevolutionary Breakthroughs in Cellular Organisms

Viruses are Earth’s major life form, having far more types than all cellular species combined. In the viral shunt, marine viruses kill 20 to 40% of bacteria daily, fertilizing the sea. The viral shunt likely increases CO₂ sequestration. Viruses play a key role in the carbon, nitrogen, phosphorous, and other nutrient cycles. Viruses increase prokaryote and phytoplankton diversity by the mechanism of kill the winner and regulating their populations. Viruses may have helped in the replacing of RNA with DNA as the genetic material in cellular organisms. They may have played a key role in the evolution of sex by meiosis, photosynthesis, the first cells, the nucleus, mitochondria, eukaryotic cells, the three domains (major categories) of life, and multicellular organisms. Endogenous retroviruses may have aided the evolution of gene regulation, the placenta, and the ability to bear live young. Viruses were important in the evolution of brain function. About 8% of the human genome originates from viruses.