• Question: How is a virus formed and picked up by one person if it didn't exist thousands of years ago?

    Asked by 802utec47 to Alison, Hannah, Jonny, MarthaNari, Paul on 23 Jun 2015.
    • Photo: Jonny Brooks-Bartlett

      Jonny Brooks-Bartlett answered on 23 Jun 2015:

      People aren’t sure how viruses originally came about. Some people think that viruses started out as large chunks of DNA from a normal cell that eventually became independent.

      A virus is essentially a piece of DNA (nucleic acid is more precise) that’s covered in a ball (which scientists call a capsid). So when the original chunk of DNA became independent it also somehow developed a protective capsid.

      Viruses then latch on to our cells using some fibres that are attached to the capsid and then inject their DNA into the cell. Because viruses have DNA, they also have the ability to mutate and adapt, which is why they are so successful at changing themselves and infecting people. When it mutates it can even change enough to infect a new species as well, not just humans.

    • Photo: Paul Brack

      Paul Brack answered on 25 Jun 2015:

      Here’s some more detail if you really want to get into it: http://www.nature.com/scitable/topicpage/the-origins-of-viruses-14398218

      In a nutshell, the article says that viruses might have come about by one of three ways; either they used to part of a cell that somehow lost some of its parts, or they came from bits of genetic code in the cell, or they developed independently of cells altogether.

Comments