> Kurzgesagt – In a Nutshell. This Virus Shouldn't Exist (But It Does). 2021. YouTube, <https://www.youtube.com/watch?v=1-NxodiGPCU>. # This Virus Shouldn't Exist (But it Does) - Viruses' origin is a mystery. - Maybe escaped DNA from cells, descendants of parasites? - Most successful organisms on Earth - Girus: giant virus. - Giruses generally hunt amoebae, creating a viroplasm inside the cell to replicate themselves - Much more complex than standard viruses: 100s or 1000s of genes compared to 10s. - Might alter the physiology of victims → chimeric organisms, or absorb genes from them - Perhaps they influenced evolution on a large scale - Virophages: viruses hunting giruses - They parasitize giruses' viroplasms - Bacteria have CRISPR to defend themselves against viruses; giruses have MIMIVIRE against virophages - Some cells have stored virophage genetic material in their DNA to produce phages against girus infection