Why do viruses replicate?

Why do viruses replicate??

I had googled for an answer and got a cryptic one liner .....'they have to, in order to survive!' And believe you me, there was just one portal which has had a direct reference to this query.??Interestingly it suggested that 'How' (How viruses replicate) was a more 'useful' question to answer! And guess what? There were innumerable portals to affirm the useful ways to answer 'how'. But?given my the then predicaments, I had almost nearly lost all hopes in the usual utilitarian view of the world - 'the truth of anything is on the efficacy of it.' How efficacious was this wanton and killer replication!?

I was quite amused to see the portal bearing the name of Socrates! The very name of Socrates turned me off! When was the last time I asked 'why' of something? I just could not recall! And here was a man who sacrificed his life in order to defend a life of philosophical inquiry. According to the account that we are afforded in Plato's dialogues, he was a man dedicated to a life of questioning.?

I always thought asking 'why' is a bad counsel, but it makes us see many things we pretend not to see. We were at a time then when we were better of being scared. Well, I had this strange feeling that?sometimes being scared is an act of courage. Else, why would I ask 'why'??

Socrates had famously said that one should read others because it is easier for him relative to the hard work done by them! I was deeply troubled reading Rocco Ronchi, a famous philosopher of our time from Italy?and he wrote from his virus ravaged country, '..the virus signals our human condition. In case we have forgotten that we are mortal, finite, contingent, ontologically wanting, the virus is here to remind us, forcing us to meditate and correct our distraction, that of compulsive consumers. For the critical insight that is being developed around the virus, Covid 19 is rather the name of a science fiction film used to certify previous knowledge.' He went on to say that if it was true that the virus displayed the characteristics of an 'event', then it must have also possessed its 'virtue'. 'Events are such not because they 'happen' or at least, not only because of this. 'Events' are not 'facts'. Unlike simple facts, 'events' possess a 'virtue', a force, a property, a vis, that is, they do something. For this reason, an 'event' is always traumatic to the point we may say that there is no trauma, there is no event, literally nothing has happened. what exactly events do? Events produce transformations.'

I hadn't read anything as profound as this during the pandemic. In a way, he was living the 'examined life worth living' of Socrates, amid the mayhem, death and despair created by an extraordinary adversary that was (and still is) an obligate parasite, an evolutionary construct!

May Ronchi rock - always and forever!??

Well, implicit in the question why viruses replicate and replicate in the scale they do, is the common mode of inferential quest in?reasoning - that is to interrogate about the 'purpose' as if there is always a 'purpose' in every facet of reality! We find it exceedingly difficult to fathom a reality that cares little for aspirations, moral principles, pain or pleasure (of organisms, especially humans).

To have a real time feel of the nature's idiosyncrasies here is a warm up case - an absolutely 'heartbreaking' one by human standards! We have semelparous and iteroparous organisms in animal kingdom. Semelparous (e.g., octopus) animals?are those which reproduce once and then they die! The final days of a female octopus after it reproduces are quite grim, it appears to intentionally speed along the death spiral! Some marsupials mate themselves to death! Humans, by its own standards, are fortunately iteroparous!! So are all known viruses. Evolution is not really amenable to our usual perception of reality.?

And that is the whole crux of the problem. Evolution implies no 'purpose'! Homo sapiens is not the 'type' of rational animal Aristotle had envisaged, but the name of a particular lineage of hominoids that happened to develop language and ratiocination! If all humans extinguish next year, they could never arise again. Evolutionary notions of species do preclude eternal types (individuality thesis). Mayr thinks that some 'taxa' (eg., families or even order) like grades can 'arrive at' more than once! But this cladistics, reconstruction of the past, or recreation of phylogeny based on present organismic distribution of traits, has few takers. We aren't sure of Mayr's thesis....let the biologists do the 'stamp collecting'!

One of the more common misconceptions is that evolution is progressive, that it gets more complex and perfect in some way (without a 'purpose' though)! This view is attributed to social attitudes than any evidence. In our routine understanding, it is a kind of a given that things get better and better, any which way,everyday. Even Darwin was ambiguous on this - talking on occasions about 'perfection' as a result of 'selection'. The debate centres around what counts as 'progress' - different measures give different results!

Well, it is 'progressive' in the way 'history' is! Biological systems are historical in two ways.....they are irreversible (they grow and die) and they are contingent. The second point is very important - the contingency factor gives it the status of science (and biologists are not mere 'stamp collectors' and 'book keepers'). You can't generally repeat an event in biology like speciation and get the same results. What is more - explanations for what something?is 'for', biologists don't say that they are 'in order to' achieve some 'end results'. It is enough to say that they are the results of selection. Period!

But there is an issue here. What do you say when you are asked, 'why do vertebrates have hearts?' You wouldn't say...'it is the result of selection' (you may have a better inheritance though)! You are likely to say ..it is there in order to pump blood around the body to carry oxygen and nutrients. This is a functional explanation. The function of the heart is to pump blood. In evolution, the question 'why do organisms exhibit adaption' is not answered with 'in order to survive' but historically - 'because those that were less adaptive didn't survive!' We ought to remember that any functional explanation begs the further question - why that function is important to the organism? -And that begs even s further questions - why should that organism exist at all? The answers to these questions depend on the history and lineage leading to the organism.

The moot point is that evolution can not be explained teleologically (that it has a goal, that it is 'end directed'.....). In an abstract sense, one may say that it is 'end seeking'!?

Consider the case of a stock broker. He has a goal....'profit'. But does the stock market has any? None whatsoever! It only has 'outcomes' (and when the stock market is sought be imposed upon a 'goal' - it crashes!). And these 'outcomes' are studied historically (and there are 'analysts' galore!).

It's just that genes replicate! It happens that those that out replicate others end up out surviving them. That coronavirus was almost out replicating us is an undeniable fact - reason or no reason! There is no goal to genetic behaviour! No teleology can account for that!

Or, Is there any? It is difficult to conceive of evolution without any goals! Let us then understand what is 'Teleology' all about. Well, To answer 'why', we often go back to Aristotle's 4 causes. Aristotle wrote that 'we do not have knowledge of a thing until we have grasped its why, that is to say, its causes.' And cause results in change/movement. He argued that there are four kinds of explanations (aitias):?

For the cause of explanation of a cell phone (why Cell Phone?),e.g.,..it is solid and made up of this and that 'matter' (material cause) , it doesn't break easily/or it is very handy/slick because of its 'form'/design (formal cause), it is there because some companies have made it using sophisticated technologies/'agents'(Agency or Efficient cause) and it has such properties because it is intended to help communicate etc (Final cause/End/Purpose). Roughly it proceeds from Matter (material) to Form to Agency to Purpose. Aristotle explains the natural world in terms of causes and purposes; evolutionary biology explains it in terms of origins and results/outcomes. It would be a good homework to explain humans in terms of Aristotlean 4 causes! Suffice it to say that it would sound absolutely vacuous if we contend that 'a human is for the sake of human' (an outcome)! We ought to remember that a child's growing up as a man (a) has 'causal efficacy', and (b) was itself contributed by his parents (Agency)!

And a statement such as 'Reptiles have scales in order to prevent desiccation on land' tacitly assumes an efficient cause, that nature arranges things purposefully, and a final cause, that scales exist for osmoregulation. In fact we know that evolution of scales long preceded the origin of terrestrial animal life, that modern amphibian classes lost their ancestral scales (which assists in dermal respiration) and that reptilian scales are of multiple origin and function.?

But, Darwin's natural selection posits no causality; it can only generate local adaptation to environments that change in a directionless way through time, thus imparting no goal or assigning a progressive victor to life's history. In Darwin's system, an internal parasite, so anatomically degenerate that it has become little more than a speck of ingestive and reproductive tissue within the body of its host, may just as well be adapted and may enjoy just as much of future success, as the most complex mammalian carnivore - wily,fleet and adept -living free on the savannas. Moreover, although the organisms may be well designed, and ecosystems harmonious, these broader features of life arise only as consequences as the unconscious struggles of individual organisms for reproductive success, and not as direct results of any natural principle operating overtly for any 'higher goals'....by taking the Darwinian 'cold bath' and staring reality in the face, we can finally abandon the cardinal false hopes of ages - that factual nature can specify the meaning of our life by validating our inherent superiority!

And to add to our misery, the more recent theory of punctuated equilibrium of Stephen Jay Gould proposes that evolution of species is not a slow, gradual process of change, but in fact consists of long periods of stability broken by shorter periods of rapid change. It is characterized by long periods of evolutionary stability, infrequently punctuated by swift periods of branching speciation! It throws any semblance of causation to the winds.

We need delve a little more into to Darwin...his 'Natural Selection', 'Survival of the fittest' etc. What is 'natural selection'? To answer this, we often say, 'natural selection is survival of the fittest!' In other words, the fittest are those that survive!?Read this again with some care! Who are the fittest? The fittest are those that survive. And who survive? Well, the ones that are fittest!! You come back by the same door wherein you enter! It's called tautology - or,circular reasoning - the conclusion and the premise go in cycles. The critics of Darwin say that it is 'survival of the survivors'!

It is one the most counterfeit phrases, 'Survival of the Fittest', (SOF) that has found its way in everywhere....in life and beyond. The underlying logic is....if evolution is a struggle for existence and survival of the fittest, then survival is the test of fitness in everything, not excepting anything....economics/sociology......: the only good economics/sociology is that which survives or succeeds! And nothing succeeds like excess.......But that is another issue!?SOF is an acronym that rhymes pretty close with a familiar swear phrase, but, every SOB is in some way a product of SOF!

This owes its origin to another sophisticated version of SOF due mainly to Karl Popper (he is famous for his 'falsifiability' thesis in Science). According to Popper, any situation where species exist is compatible with Darwinian explanation, because if those species were not adapted, they can not exist! That is, to Popper, adaptation is that which is 'sufficient' for existence in a given environment. It means nothing is ruled out because everything is ruled in! And most strategies that we saw to get out of the covid?situation fall into this. I quote a personal example. I had received a request to select a cover design for the HBR's publication. They asked?me to choose one from three designs;all three designs annotated the same text,'Emerging from the Crisis'! All we were trying, then, was to return to the given familiar 'environment'/Normalcy! I thought it would have been appropriate to change it to 'Evolving into the new environment' rather than 'Emerging from the Crisis!'??

?'Fitness' to Darwin meant not those that survive, but those that could be 'expected to survive' because of their adaptations and functional efficiency, when compared to others in the population. The phrase 'survival of the fittest' was not even Darwin's, it was coined by Herbert Spencer some years before 'Origin of species' came into being! Darwin preferred 'natural selection' taking a cue from 'artificial selection' (as done by breeders). Darwin was cajoled by the co-discoverer of 'natural selection', Wallace (who hated this phrase because he thought that the word 'natural' implies some agency doing the selecting).

SOF refers to the fact that given a selective regime in the real world, a population will tend to evolve in the same direction over and over, and we can often predict in advance what the response will be. For example, black moths will increase in frequency if trees are dark. It isn't that whatever survives survives, it is that particular 'traits' are preserved depending on the environment. 'This preservation of favourable variations, and the destruction of injurious variations, I call natural selection or survival of the fittest.' And Darwinism rules out a lot ...'inefficient organisms', 'change' that is theoretically impossible to achieve in gradual and adaptive steps. More importantly, it rules out new species without any ancestry! Besides, you can never expect a 'pair of spectacles' no matter how long you persist; some sense organs, like eyes, are just not amenable to evolution.?

The current understanding of fitness is 'dispositional', i.e., fitness is a disposition of a trait to reproduce better than competitors. It is not deterministic (and that's the whole problem). Adaptation is also not just defined in terms of what survives. Adaptation is a functional notion and not a logical or a priori or semantic definition (it is also not deterministic). If two twins are identitical genetically, and therefore are equally 'fit', there is no guarantee that they will survive to have equal numbers of offspring. Fitness is a statistical property. What 'owns' the fitness isn't the organisms, but the genes! They will tend to be more often transmitted so far as what they deliver is better engineered to the needs of the organisms in the environment in which they live. You can determine that, within limits, by reverse engineering the traits to see how they work.

Moreover, fitness exists over and above the properties of individual organisms them selves.There are three debated ways to construe this. Fitness can be a relation of genes to other genes.Fitness can be a supervenient property - that is, it can be a property of very different?physical structures. Or fitness can be seen as an emerging property, a property of systems of a certain complexity and dynamics. Whether fitness is a genetic, organismic or a system property...is yet to be fully explored. I think the system interpretation is the way to approach it.

The adaptive explanation of fitness has its naysayers! These fall into two groups - those who think that adaptation isn't enough to explain the diversity of form, and those who think that adaptive explanations require more information than one can obtain either from reverse engineering or the ability to generate plausible scenarios. The reason given for the former has its roots in incredulity - natural selection is not thought to be a sufficient cause and that macroevolution (evolution at or over the level of the species) is a process of different kind than within species. Arguments about parsimony abound.

The second argument - that selective explanations needs supplementing - rest on the causal efficacy of selection (which is not denied) but on the problems of historical explanation. In order to explain why a species exhibits this 'trait' rather than that 'trait', you need to know the null hypothesis (otherwise you can make a selective explanation for both a case and its opposite as well). Perhaps it has this trait because his ancestors had it and it has been maintained by selection. Perhaps it has it because it is too disruptive of the entire genome and developmental machinery to remove it. Perhaps it has it for reasons to do with genetic drift, simple accident, or whatever. Also, SOF refers to only one aspect of evolution - the selection process - not the entire theory! SOF refers to no aspect of 'macro evolution'; not to the creation of new species, or to the tree of common descent generated by speciation, or the nested hierarchy of characteristics within the tree; nor does it refer to mutations as the cause of variations. The fitness is intended to refer to specific heritable characteristics. In order to make good a scientific explanation, you must know a fair bit of phylogeny of the species, its environmental distribution, and how the processes that create the trait work at the level of the genes, cells and zygotes.

And lastly, we also need to reflect upon the word, 'nature'. Does nature have a 'purpose' to 'breed' life? That's a very difficult question. But, if you just consider one example, that of water at 4 degree Celsius, it turns out to be the temperature at which liquid?water has the highest density. If you heat it or cool it, it will expand (That's why ice floats on water). No other liquid has that property and life is inconceivable without this inherent property of water. Nature, therefore, has properties that go to breed life! And if Nature selects something, that selection can not be construed to end 'lives' altogether! This gives us hope! This definitely signals at a 'purpose'. But, this is yet another subject to deal with.