Viruses and Life's Definition: Debate Continues & Asgard Archaea Shed Light on Complex Life Origins

The scientific community continues to debate whether viruses can be considered living organisms. Viruses possess genetic material (RNA or DNA) and evolve, but lack the machinery for metabolism, depending on host cells to reproduce. They are viewed by many as "entities on the limit of life," playing a role in evolution and ecosystem regulation. Research in virology has spurred new technologies in gene therapy and vaccine design. New research suggests that Asgard archaea, ancient single-celled microbes, may hold answers to the origins of complex life. Discovered in 2015 from deep-sea sediments, these archaea share similarities with complex organisms. Professor Martin Pilhofer's team at ETH Zurich examined *Lokiarchaeum ossiferum*, an Asgard archaeon isolated by researchers at the University of Vienna. They found it possesses structures typical of eukaryotes. According to Pilhofer, an "actin protein in that species appears very similar to the protein found in eukaryotes." Furthermore, ETH researchers discovered that Asgard tubulins form microtubules, similar to those in eukaryotes, albeit smaller. These findings suggest the cytoskeleton was an important step in the evolution of eukaryotes, potentially enabling Asgard archaea to interact with and engulf bacteria.