Lessons from viral pandemics

Viruses are ubiquitous in every habitat and are the most abundant species on our planet. Most ancient are RNA-containing viruses. They may have contributed to the origin of life, since naked RNA-only viruses, the viroids, lack genetic information. They fulfil several criteria of life. Could such structures have contributed to life on exoplanets somewhere in the Universe ? Viruses are innovative, can integrate into genomes thereby supplying novel information and immunity to the host, protecting against superinfection by exogenous viruses. They are the drivers of evolution. As such they contributed e. g. to the placenta in mammals. The human chromosomes consist of about 50% viral elements. Sub-viral structures such as transposable elements can contribute to genetics beyond Darwinian mutations. Bacterial viruses, the phages, can help to recycle nutrients in the oceans and our intestines and can destroy multi-drug resistant bacteria as phage-therapy. They may be a way out, if antibiotics fail. Antibiotic resistance my soon become critical. Phage therapy is a hundred years old, but has been neglected. Novel technologies may be able to reactivate this technology.