Do viruses eventually cause species extinction?

[synch]

I am wondering if some complex species have an in-built probable extinction span.
The logic goes : Species X originates, individuals have a long lifetime and require a long development before adulthood and so a slow generation rate. Viruses that are much simpler cross to species X, and mutate and generate much faster that the generation rate of X. The virus population depends on the X population, and evolution of immunity.

As species X expands to its niche, the creation and spread of the new virus mutations also expands. At some time the slow generation and immunity development rate of X is outstripped by the increasing arrival of new virus mutations and infections, and the population of X crashes and is then prone to extinction.

It should be possible to model that mathematically of course.

 

[fresh_42]

Viruses need a host. Why should a virus cause the extinction of its host? That doesn't make sense.

 

[Vanadium 50]

If the question is "if in the history of life on Earth, has the last member of a species ever been killed by a virus?" the answer is probably yes, but that species was also obviously on its way out anyway. If the question is whether a successful species is suddenly wiped out to the last individual by a virus, probably not. I don't think there is a case of uccessful species being suddenly wiped out by anything other than a mass extinction event.

 

[DaveC426913]

Viruses that are much simpler cross to species X, and mutate and generate much faster that the generation rate of X. The virus population depends on the X population, and evolution of immunity.

As species X expands to its niche, the creation and spread of the new virus mutations also expands. At some time the slow generation and immunity development rate of X is outstripped by the increasing arrival of new virus mutations and infections, and the population of X crashes and is then prone to extinction.

Sure, that may happen, but viruses are simply one more survival pressure that drives evolution - albeit possibly faster than, say ecology change.

But ofttimes, a species' solution to a virus is not to expunge it, but to cope with it, even benefit from it. All critters are rife with viruses that have been incorporated.

In fact, I think there is a line of research that suggests we could not have evolved in the ways we did without the direct involvement of viruses.

 

[Algr]

As species X expands to its niche, the creation and spread of the new virus mutations also expands. At some time the slow generation and immunity development rate of X is outstripped by the increasing arrival of new virus mutations and infections, and the population of X crashes and is then prone to extinction.

The reverse of this would also happen. Once the population is reduced, viruses would be better off moving to new targets rather than sticking to hosts that are now hard to find.

 

[Rive]

...and the population of X crashes and...

Well, at the point when the original population breaks down to isolated smaller populations due the collapse the spread of the virus is supposed to slow down considerably.
Feels possible that some special virus-host combinations may lead to extinction, but I think such collapse to trigger further evolution/appearance of new species is more likely.

 

[tech99]

If the question is "if in the history of life on Earth, has the last member of a species ever been killed by a virus?" the answer is probably yes, but that species was also obviously on its way out anyway. If the question is whether a successful species is suddenly wiped out to the last individual by a virus, probably not. I don't think there is a case of uccessful species being suddenly wiped out by anything other than a mass extinction event.

The Elm Tree was suddenly wiped out over vast areas of England by Dutch Elm Disease, and only preserved by Man's conservation activities in one location.

 

[fresh_42]

The Elm Tree was suddenly wiped out over vast areas of England by Dutch Elm Disease, and only preserved by Man's conservation activities in one location.

That's caused by fungi, not viruses.

 

[pinball1970]

I am wondering if some complex species have an in-built probable extinction span.
The logic goes : Species X originates, individuals have a long lifetime and require a long development before adulthood and so a slow generation rate. Viruses that are much simpler cross to species X, and mutate and generate much faster that the generation rate of X. The virus population depends on the X population, and evolution of immunity.

As species X expands to its niche, the creation and spread of the new virus mutations also expands. At some time the slow generation and immunity development rate of X is outstripped by the increasing arrival of new virus mutations and infections, and the population of X crashes and is then prone to extinction.

It should be possible to model that mathematically of course.

Just look at historic viruses, Smallpox, Polio, Influenza.

Are looking at a mathematician model? Ian Ferguson did work pre covid. Atty and yyyg have a stack of refs on that.

 

[fresh_42]

Covid-19 is a good example. All mutations became more and more infectious and less and less fatal. That makes sense from an evolutionary point of view.

 

[pinball1970]

Covid-19 is a good example. All mutations became more and more infectious and less and less fatal. That makes sense from an evolutionary point of view.

More infectious yes but all less lethal?

 

[fresh_42]

More infectious yes but all less lethal?

The hospitalization numbers are decreasing here.

 

[Rive]

All mutations became more and more infectious and less and less fatal.

It may worth to clarify that the general decrease of fatality was not due evolution (of either the host or the virus) but due the adaptation of immune system of the individuals of the human population.

 

[pinball1970]

Yes. Here too. What I was saying is Covid did mutate in terms of transmissions but did not always decrease in terms of how lethal it was. Or did it? Did it? Delta to Omicron yes. I need to look back.

 

[fresh_42]

It is always a dynamic system between viruses and hosts. I am just saying that a virus does not have an evolutionary advantage to kill its hosts. Even yersinia pestis didn't kill entire societies or the American flue between 1918 and 1920.

 

[Vanadium 50]

That's caused by fungi, not viruses.

And some trees are resistant.

 

[.Scott]

It may worth to clarify that the general decrease of fatality was not due evolution (of either the host or the virus) but due the adaptation of immune system of the individuals of the human population.

From the viruses point of view, the best it can do with people is:
1) persist, replicate, and mutate within an individual giving it an opportunity evolve; and
2) to communicate freely from one individual to the next while producing no symptoms.

The immune system presents challenges to the virus on both of those counts.
But viruses that kill and create symptoms quickly are doing themselves no favor.
So there is Darwinian pressure for viruses to become less fatal and, (especially with people) generally more tolerated by their hosts.

Actually demonstrating that the Omicron virus itself has followed this trajectory is a challenge.
Here is an article that examines Omicrons lower lethality: JHU Article
But when everything is changing - medical treatment, vaccination rates, etc. it's hard to tell how each factor is affecting the lower fatality rate.

 

[Rive]

But viruses that kill and create symptoms quickly are doing themselves no favor.
So there is Darwinian pressure for viruses to become less fatal and, (especially with people) generally more tolerated by their hosts.

Regarding the misconceptions around the whole 'less deadly over time' thing please consider the content of this topic.

To be honest, I'm a bit surprised that it's still around in this form. During the pandemic this thing were discussed quite regularly.