If viruses usually aren't considered alive, why would obelisk? I'm also curious how we know these are independent structures versus a by product of our own or our resident bacteria's cellular function. The mRNA seems unrelated to our own, but perhaps there's an unknown process that either generates new extracellular mRNA to create these protiens referenced in the article. Alternatively, could these be mRNA strands that escaped the cellular destruction process?
As someone who works on viruses, we don't worry or care whether viruses are alive.
It's more of a philosophical question, and distilled down its really about whether viruses fit into a human centric view point of the world. We like to classify things into discrete groups. Biology is not discrete.
I do not agree with considering viruses as not alive.
A viral particle outside its host can be considered dead, in the sense that it is inert and it does not have any metabolism, but it is not definitively dead, as it will become alive again when entering a host. Alive in the sense that inside their host cells viruses observe the command "Crescite et multiplicamini" from the bible (grow and multiply), in the same way like any other living beings, even if they have to take control of various components of the host cell in order to do that.
I do not see any essential difference between a viral particle and a dormant seed or a bacterial or fungal spore or an encysted protozoan.
All such resistant forms of living beings have the purpose of remaining intact in environments where they cannot found the food or water or air that they need for a normal life. Viruses have the least demands from their environment, while the others may have greater requirements, e.g. the presence of small amounts of free oxygen and water in their environment, in order to not die permanently, but that is more like an imperfection in their current design, not an intrinsically necessary attribute.
Viruses cannot live without their hosts, but that is true for any obligate parasite. Humans can also not live independently, at least for now, but only together with many other living beings able to synthesize the substances that we cannot. Therefore it is hard to draw a line between alive and non alive based on the amount of dependencies on other living beings.
It certainly is more useful to include viruses in what is covered by the word "alive", because they are subjected to the same kind of evolution like the cellular living beings. Moreover in the same way like many kinds of cellular living beings have appeared by hybridization between cellular living beings with distinct genetic heritage, there are also plenty of cases where new species of cellular living beings have appeared by hybridization with viruses, i.e. by incorporating permanently in their genome some genetic material from a viral ancestor. This includes even humans (and all other vertebrates).
Therefore, if you draw a graph of the genetic relationships between cellular living beings, it is inextricably intermingled with the corresponding graph for viruses.
So I think that the most convenient way is to consider that the living beings are divided into cellular living beings and viruses.
Regardless of the word choice, biology must study both cellular living beings and viruses, anyway, because none of them can be understood in isolation from the others.
It's as the sibling post says: "alive vs not alive" and "same species vs different species" are just human concepts that we attempt to shoehorn biological reality into. There's nothing about biology itself that says that any given example should have a clear answer either way.
Humans don't grow, convert nutrients to energy, or reproduce independently.
Humans need every day about 30 organic substances that they cannot synthesize, so these substances must be obtained from bacteria, plants and other animals.
Due to having internal reserves, a human will not die immediately when isolated from other living beings, but only after a month or even slightly more. A month of independent life is not enough to grow and reproduce.
However a virus that is encapsulated in its transmission form will also not die definitively immediately, but it can survive for many years independently of any other living beings, i.e. much more than a human can live independently.
There is a huge complexity chasm between any bacterial cell and a virus, but there is also a huge complexity chasm between a virus and any mineral or any chemical substance whose synthesis is known to be possible in abiotic conditions.
There is no doubt that cellular living beings and viruses are 2 very different kinds of things, but both are also very different from any non-alive things.
There are many characteristics common for cellular living beings and viruses, so normally one would need a single word for both of them, to avoid enumerating both of them whenever a sentence is true for both.
The most convenient is to call both of them as living. Those who do not include viruses between living beings utter extremely frequently sentences that are either incorrect or incomplete, because they are true for both cellular living beings and for viruses, but the authors mention only "living beings" with the meaning "cellular living beings", even if those sentences are equally true for viruses.
If you call viruses as non-living, then you must also say that humans and most animals have among their ancestors non-living entities, because our genome incorporates genes that have been obtained from viral ancestors.
The concept of viruses as "non-alive" has been an overcompensation for the previous belief that viruses might be living beings like any others. When it has been discovered than viruses are very different from cellular living beings there has been a fashion to call them non-alive, to demonstrate that one is up-to-date with scientific knowledge and one knows that viruses are very different from cellular beings in many features, even if they are alike in others.
Unfortunately this phenomenon has been very frequent in the history of scientific terminology. There are plenty of examples when after some people had discovered that some things are more different from other related things than previously believed, they gave a new name to their discovery, claiming complete distinctness from what was previously known, even if the correct point of view was midway, i.e. even if the new things were distinct enough to be classified as something different, they also shared enough characteristics with what was previously known to be better considered as just a new subclass of those things.
Funny how they replaced one performative mantra with another, which is just the same as the one they wanted to get rid of: you have to recite the $SYMBOL_OF_FAITH before you can have a job or apply for a grant.
In fairness, that's what all political types do. It's all just quasi-religion all the way down. Anyone who thought any different was fooling themselves. It's unfortunate that it comes at the expense of scientific research, but hey, that's what people voted for.
Everyone in the US is getting exactly the government we deserve. That's the beauty of democracy! You get government that's precisely as good, or as bad, as you deserve. And you deserve government no better, or worse, than what you get.
The analogy breaks down in that rate of infection of a disease is historical but very much informs ongoing public health measures that should be taken.
It’s just a fact it really changed my perspective. American as a people have a learned helplessness mostly because of wealth, when asked to do something they gripe about the boss making excuses and acting juvenile. Asians just do the thing.
You think the study of archeology, anthropology, genetics, and ecology across the entire Western academic system is being subverted to support DEI using a theory that existed long before the time "DEI" was a known acronym? And you can't provide evidence?
Out of Africa was fought by the majority of Western scientists during the early 20th century because of their pro-European biases. The reason its accepted is because the preponderance of evidence supports it.
there were also a lot of sociocultural changes coming out of the 60s/70s that changed the scientific conclusions we drew.
it used to be that we saw changes in ancient pottery and language and assumed that previous people had been replaced by new people with different techniques. then, in the 60s/70s it became popular that these changes didn’t mark population replacement but were more cultural spread and shift.
then genetics came around in the 90s and obliterated the cultural hypothesis and showed that in most of these cases it was largely population replacement.
there are lots of theories from the mid-20th that haven’t yet had their ‘genetics in the 90s’ moment.
> then genetics came around in the 90s and obliterated the cultural hypothesis and showed that in most of these cases it was largely population replacement.
I think the current consensus is a fusion of the two stances, particularly as some of the changes have appeared to be too rapid to reflect population displacement, and genetics clearly indicate genetic admixture with varying distinguishing characteristics relevant to the region and timeperiod as opposed to straight displacement.
Unsatisfying, I know, but basically any firm position on either side has equally firm arguments against it.
I had a recent discussion about this, will try to pull up the sources, but my understanding is displacement is the majoritarian current and cultural shift with same population very much a secondary that only applies in a minority of the cases
a lot of these admixture events show near total displacement of the y chromosome also
I'm not disbelieving your source entirely, but it seems a little ridiculous to assume population displacement across all pre-history (or undocumented history if you'd prefer that term). Particularly when modern populations are so genetically diverse.
For one example, the idea a single "sea people" were responsible for the shift from bronze age to iron age in the eastern mediterranean is nearly universally rejected at this point. The populations of the mediterranean seem to descend at least in part from the bronze-age populations of the area. However the economic and cultural impact of the same period undeniably transfused rapidly through the region as heavily demonstrated with the archaeological record.
Even in the case of neanderthals we didn't fully displace so much as mostly displace but also admixed. Same with denisovans, cro magnons, etc. Genetic testing of cro-magnons shows modern-day descendants, and not just in the matrilineal or patrilineal line (i.e. presumably indicating either descendants of rape or partial infertility, as is presumed in the case of neanderthals).
With the spread of agriculture (seed cultivation, husbandry, plow, etc) we also see a mixture of genetic and cultural transfusion. Ditto with the horse, except much more rapidly, and horse-based technology much slower. This is partially why there's a gradient of genetic similarity across europe rather than a "european" set of genes—and with the horse technology, we have the benefit of an archeological and in certain cases textual evidence of trade between northern europe and the rest of the world.
Now, some of this is a matter of quibbling over semantics—is it displacement or is it admixture? Understandable. But the cultural diffusion in the material record is undeniable regardless of which term you pick. I'm not so sure it's worth picking a primary cause rather than accepting the inherent messiness of the archeological and genetic record where, as in the case of neanderthals, there isn't very solid evidence of infertility demonstrating firmly that the migration was mostly, if not entirely, displacement, as presumably non-hss-mixed neanderthals are extinct.
>when modern populations are so genetically diverse.
Are they? Are there any studies that confirm that hypothesis?
My understanding[0][1][2][3][4][5][6] (there are plenty more references, but I assume you get the point) is that modern human populations are incredibly similar, and not very diverse at all. In fact, all humans are more genetically similar to each other than many other species are, including chimpanzees and wheat.
> Are they? Are there any studies that confirm that hypothesis?
??? what is there to confirm? Why are you trying to spin an internal comparison as external? Indigenous populations tend to be more related to physically close indigenous populations than physically far apart indigenous populations. This is what I was referring to with the "genetic gradient". Comparing us to chimpanzees makes zero sense, let alone wheat, as we aren't trying to have sex with either, let alone "displace" them. I mean, hopefully not.
It's true that our diversity has lessened over time but this is "I don't see color" levels of delusion.
when modern populations are so genetically diverse.
They are not. Humans as a species (in case you're not understanding what I mean by "species," I mean all the bipedal primates generally referred to as "Homo Sapiens") are not very genetically diverse.
And I provided documentation to support that assertion.
I didn't even get into the genetic evidence that variation within human population groups is greater than the variation between such groups.
That you made some sort of assumption as to the reason for my assertion, is on you and not me.
I merely pointed out that your assertion is not supported by the genetic evidence. Full stop.
I don't understand why you're using diversity in this comparative manner when I was clearly not. I was just pointing out there's a lot of genetically distinct humans and this genetic distinction follows geographic trends. It's your choice to interpret it as a comparison to other species and frankly I'm bewildered why you decided to take the conversation there.
>I don't understand why you're using diversity in this comparative manner when I was clearly not.
Clear to whom? You? I'm sure it was. To anyone else? Not so much.
I read your words "I'm not disbelieving your source entirely, but it seems a little ridiculous to assume population displacement across all pre-history (or undocumented history if you'd prefer that term). Particularly when modern populations are so genetically diverse."
And you made the claim that "modern populations are so genetically diverse." Did someone commandeer your account or force you to write that at gunpoint?
If not, it was you who referenced genetic diversity.
Or does "modern populations are so genetically diverse" mean something other than "modern populations are so genetically diverse?"
As for my response, my apologies. Clearly I did not communicate my thoughts effectively. I will attempt to do so again.
>I was just pointing out there's a lot of genetically distinct humans and this genetic distinction follows geographic trends.
And your assertion is flat wrong. In fact, modern humans have very little genetic diversity, measured any way you'd like.
What's more, the human populations with the most genetic diversity are those native to Southern and Eastern Africa.
Populations everywhere else in the world are incredibly genetically similar to each other.
So much so that the differences within geographical population groups are greater than those between such groups.
As to my references to chimpanzees and wheat, that was just to point up that humans -- regardless of geographical population -- are not genetically diverse at all.
And that's it. Humans, regardless of geographic population, are remarkably similar in genetic make up. Humans are not, as you asserted, "so genetically diverse." Exactly the opposite.
Do you understand now? If not, I obviously need to learn to write more clearly.
Diversity does not imply comparison to other species. I'm still struggling to figure out how that entered the conversation. We are either diverse or not, and we are not clones, so we are diverse.
This is one of the most unpleasant conversations in recent memory. Haven't you ever heard of good faith conversation? Jesus. Absolutely rank vibes.
Humans, regardless of geographic population, are remarkably similar in genetic make up. Humans are not, as you asserted, "so genetically diverse." Exactly the opposite.
No doubt those biased Europeans felt their theory had the preponderance of evidence behind it. Funny how often the settled science is like that until the incumbent scientists die off rather than because better evidence was considered and adopted by science.
I don't think a group of people living somewhere for thousands of years would be "getting it wrong." You're embedding an assumption that evolution has been working toward an end goal of getting humans to spread globally, which isn't how evolution works.
It doesn't seem all that improbable that humans or close ancestors had colonized other parts of the world for thousands of years only to die off due to climate change/disease/other factors about 40,000 years ago when they had to start all over again. Or maybe the ancestors colonized it and the extinction event was Homo Sapiens out of Africa, although in this case you would expect more DNA mixing. It seems more likely that the ancestors died out for whatever reason and the humans moved into their habitats to refill that ecological niche.
I don't see how you could say that's more likely without evidence, lack significant gaps in archaelogical finds between eras of human presence in a region.
Oh, and fun fact: an Apollo moon mission racked up nearly 3 million passenger miles per flight and did not suffer a single fatality. Even if the astronauts on Apollo 13 had not survived, and the whole program cancelled right then and there, by fatalities-per-passenger-mile a Saturn V to the moon would still be far "safer" than driving, which averages one death every quarter of a million miles.
I think this demonstrates two important flaws with the "passenger miles" concept: 1, miles are not always fungible between modes of transport. 2, intuitively we care more about the risk per trip, rather than the risk per mile.
