A list of hypothesis about viral evolution are listed here.
There are five hypothesis about how viruses evolved. However I vaguely recall hearing on a scientifically oriented ratio show that viruses could have evolved as a form of horizontal gene transfer between single celled organisms. Maybe bacteria wanted to pass genes between each other so viruses were used for that, but some of the viruses just started making copies of themselves instead of passing genes between cells.
Does anyone know if thats a valid theory in the evolution of viruses, and if so what is it called? I don’t think I see it on the wikipedia page.
You can get twisted up if you try to fit sentient behaviour into evolution.
Maybe there was a evolutionary development which allowed horizontal gene transfer. And that genetic left turn at Albuquerque evolved into some forms of virus.
But a colony of bacteria weren’t sitting round the office water cooler just chewing’ the fat when one of them said “Guys, I reckon I’ve thunk out a way to do HGT.”
A mutation occurred, it provided advantageous, it thrived.
I understand bacteria aren’t sentient, but the article I linked to discussed five different hypotheses about the evolution of viruses, but none described horizontal gene transfer as one of those possible factors, so I’m wondering if horizontal gene transfer is considered a valid theory on the evolution of viruses, were viruses originally evolved and used for gene transfer, then they evolved to become parasitic instead.
We attribute sentient qualities to things that happen naturally. Evolution isn’t a conscious process; it just kinda happens. There are many adaptations that are not advantageous and many of these mutations just end up being a bunch of nothing. There are a select few mutations that happen to be ideal for an environment, and they end up surviving.
Take dogs, for example. It so happened that one out of 100, 1000, 10,000X little wolves had a genetic predisposition that enabled them to be a little less aggressive toward people. Said wolf (dog) befriended people, and realized they didn’t always have to hunt for food, giving them an advantage over their wolf brethren.
I don’t see how that pertains to my question though. I didn’t think bacteria were sentient, but they do have horizontal gene transfer. Was horizontal gene transfer using viruses part of why viruses evolved.
The ‘escape hypothesis’ could be related to horizontal gene transfer though, but its not discussed explicitly.
The first thing to realize is that evolution doesn’t favor traits that help organisms; it favors traits that help genes. The process by which a virus would evolve “to help horizontal gene transfer between bacteria” is exactly the same as the process by which a virus would evolve to help the virus. It might happen to have helped the bacteria in the process, but that’s completely irrelevant, evolutionarily.
Maybe the critical word here is plasmid, which is are chunks of DNA that bacteria can pass between each other and there is indeed the hypothesis that these are the precursors to viruses; though the hypothesis doesn’t have a distinct name that I can find, and I am not sure why the wiki on virus evolution doesn’t mention this.
Here’s a (very short) article about a plasmid that apparently is in the process of becoming a virus (link).
Viruses are deeply different from each other–DNA and RNA, sense and anti-sense, single-stranded and double-stranded. They may have originated more than once.
