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Shouldn’t new strains be more contagious but less deadly?
by hartator 6y ago
Shouldn’t new strains be more contagious but less deadly?
- Someone1234 6y agoWhy "should" they be?
- hartator 6y agoBy darwinism.
- eternalban 6y agoNatural selection. Deadlier strains reduce life span of hosts that transmit the disease.
- dvfjsdhgfv 6y agoYou mean the natural selection of hosts, not viruses. Why should one kind of organism "care" about the natural selection of another?
- yibg 6y agoIt’s not about caring but what survives. Viruses variants that regularly kills hosts are less likely to spread than ones that don’t.
- eternalban 6y agoI'm in agreement wtih @yibg. > "You mean the natural selection of hosts, not viruses", No, just simply 'natural selection', as the overall process that determines which entities get to reproduce. Natural selection for the hosts is about their chances for reproducing (before dying from the disease). And in this case, we don't care about that since its a fair assumption that the patient is not having sex in ICU. :) Natural selection for viruses is about having the opportunity to jump hosts and replicate more viruses. The longer the host lives the higher the chances for the virus to propagate.
- bserge 6y agoIs that the case when the hosts are all in good shape (compared to even 200 years ago) and use "artificial" means to stay alive longer?
- morlockabove 6y agoIn good shape? When half the population of the western world is obese, and 10% are diabetic? How many people, on average, were on the brink of starvation 200 years ago? We're still better off, I'd guess, but it's not that amazing
- bserge 6y agoHmm, you've got a point, but what kind of "obese" are we talking? Usually people conflate obese with overweight. Being (slightly) overweight is generally good for health, especially when combating a virus. 200+ years ago the vast majority of people were definitely starved for nutrients, living off whatever they could get locally, with very little meat compared to today.
- kadoban 6y agoAbsent any special considerations, that's the general direction that pathogens go, more infectious and less deadly. Dead hosts aren't a benefit to the virus, and neither are hosts too sick to go out and infect others. Evolution is messy though, I don't know how likely a particular new strain is to go that direction.
- andi999 6y agoAlso in the case of corona, the virus is more infectious if it is in the upper respitrory system and not in the lung.
- dvfjsdhgfv 6y agoWell, if the "aim" of the virus (what is ours, btw?) is to replicate as much as possible, the best "strategy" would be to be highly contagious and remain dormant for as long as possible; fatality would be an obstacle rather than advantage. There is just one problem with this approach: as far as we can tell viruses aren't intelligent and they don't think. On the other hand, if you consider the possibility that viruses might be a tool used by someone else (God, aliens, evil scientists hired by bad governments), fatality becomes an important, if not the defining aspect of the tool.
- nicoburns 6y agoI think it's important to remember that viral mutations are random. Therefore to a large extent there is no purpose. What there is are traits that make a given mutated version of the virus more likely to spread and thus come to our attention.
- throwaway316943 6y agoThey don’t think and they don’t control their mutations but selection acts on them and “chooses” the strains that reproduce more. Pathogens become less deadly with subsequent generations because those strains which kill the host quickly limit their spread. It’s not impossible for them to become more deadly but it is unlikely due to the fitness cost.
- ericbarrett 6y agoIt’s entirely possible for a mutation to make the virus more deadly and more contagious at the same time, exploit a window of opportunity in an unprepared population, then “burn out.”