Living Viruses 🦠

[DarkRange55]

I don't think there should really be any question on whether viruses are alive. They evolve through natural selection, they reproduce, they have parasites of their own, some of the larger ones even have their own metabolism.

I've seen two arguments against it – one, that they don't have cells , and second, that they don't have their own ribosomes to make proteins. In the first regard, I see no reason that cells are essential to being alive (I think that it is a biased position from people who happen to have cells_). In the second regard, Isaac Asimov settled it for me when he pointed out that a woodcutter who borrows an ax is still a woodcutter even though he doesn't have his own ax.

 

[Forever Sleep]

One thing I've always been curious about. In the more lethal ones- like Coronaviruses, rabies etc. why do you suppose they have evolved to (likely) kill the host? Surely- that isn't in their advantage because, they presumably die with it. Wouldn't it be better to keep the host alive and well so that it can pass the virus on to as many other creatures as possible?

I guess some viruses don't actually mean to kill the host. Don't many of the coronaviruses originate in bats? Yet, they seem to live safely with them.

I wonder why viruses didn't evolve to be symbionts. Imagine that? You contract something that actually helps you. Wouldn't that be cool? The amazing algebra virus. You wake up a genius.

But sure, it seems to be alive on some level to me. Maybe that's one major criteria- that the thing is able to reproduce and, has a drive to do that.

 

[DarkRange55]

One thing I've always been curious about. In the more lethal ones- like Coronaviruses, rabies etc. why do you suppose they have evolved to (likely) kill the host? Surely- that isn't in their advantage because, they presumably die with it. Wouldn't it be better to keep the host alive and well so that it can pass the virus on to as many other creatures as possible?

I guess some viruses don't actually mean to kill the host. Don't many of the coronaviruses originate in bats? Yet, they seem to live safely with them.

I wonder why viruses didn't evolve to be symbionts. Imagine that? You contract something that actually helps you. Wouldn't that be cool? The amazing algebra virus. You wake up a genius.

But sure, it seems to be alive on some level to me. Maybe that's one major criteria- that the thing is able to reproduce and, has a drive to do that.

One thing I've always been curious about. In the more lethal ones- like Coronaviruses, rabies etc. why do you suppose they have evolved to (likely) kill the host?

They generally don't kill their original hosts (e.g., bats), or do so only slowly. Some also have not yet had time to fully adapt to their new hosts.

Surely- that isn't in their advantage because, they presumably die with it. Wouldn't it be better to keep the host alive and well so that it can pass the virus on to as many other creatures as possible?

It's a trade-off. Diseases that can spread easily even from bed-ridden people have much less incentive to keep you healthy.

I guess some viruses don't actually mean to kill the host. Don't many of the coronaviruses originate in bats? Yet, they seem to live safely with them.

Bats have very strong immune systems for viruses, so when viruses do spill over they can overwhelm other species' weaker defenses.

I wonder why viruses didn't evolve to be symbionts.

Some have. Some even defend their host cells against other viruses.