Were there already viruses on Earth when the first living cells appeared billions of years ago? – Aayush A., age 16, India ...

Viruses, then, may have existed before bacteria, archaea, or eukaryotes (Figure 4; Prangishvili et al. 2006). Most biologists now agree that the very first replicating molecules consisted of RNA ...

“The evolutionary history of RNA viruses is at least as long, if not longer, than that of the cellular organisms,” wrote the authors. Often ignored is the third branch of life, archaea. Evolved during ...

Viruses can replicate only inside a host’s cell. Hosts of viruses include animals, plants, bacteria, fungi, and archaea. Many viruses have evolved to infect multiple kinds of hosts, while some ...

The viruses that infect Asgard archaea are unique from those that have been described before.

Several studies over the past few years have highlighted a potential link between our gut microbiome (not just bacteria, but ...

The genomes of giant viruses, such as the recently discovered Mimivirus that infects amoebae, are larger than the genomes of many bacteria and some archaea (Raoult & Forterre 2008). Viruses ...

How understanding the gut can help veterinarians understand cognitive and behavioral health in dogs.

Earth is microbial: bacteria, archaea, viruses, protists and fungi are the largest store of biomass on the planet and represent nearly all of its biodiversity. They store massive genetic resources ...

Bacteria and archaea are single-celled creatures that ... Some scientists consider viruses to be microbes made of genetic material enclosed in a protein coat. They are unable to replicate on ...

Another popular theory states that viruses evolved from degenerated bacteria or archaea that lost most of the genetic instructions for carrying out metabolism and forming cells. There are many ...