Viewing a single comment thread. View all comments

bruceleroy99 OP t1_izb8uig wrote

Reply to comment by BetterLivingThru in Have living things always had an immune system? How did they survive / evolve to deal with diseases, and how does that compare to modern immune systems? by bruceleroy99

ooooh got it, that makes a lot more sense! extremely informative, too, thanks! I assume it isn't known at what point viruses / bacteria developed alongside everything? e.g. if single-celled organisms are 1000s x bigger than viruses, how big were things when viruses first started forming?

9

clocks212 t1_izbtz5k wrote

It’s unknown whether cellular life came before viruses or if cellular life evolved from viruses.

10

mcr1974 t1_izc29sd wrote

but what would have viruses attacked?

2

the_quark t1_izc59cy wrote

They might have started simply as self-replicating sets of chemicals in the early ocean. At this point though we've only been able to speculate about their (and life's) ultimate direct origin.

8

Octavus t1_izd243f wrote

There are also viroids which are even simpler than viruses. They are simply a circular strand of RNA, that is it. However they are still able to infect plants, use their cellular machinery to create more copies, and spread.

4