an autodidact meets a dilettante…

‘Rise above yourself and grasp the world’ Archimedes – attribution

Posts Tagged ‘origins

on religion and explanation

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it’s true

Jacinta: I’ve been thinking about religion as the earliest form of explanation for a while, and about when we – our species, or our ancestors – began to feel the need for explanations, about everyday regularities and irregularities, such as why the blinding white disc travels across the sky, disappears, plunging the world into darkness, then reappears on the opposite side and retraverses the sky again. And again and again. Or why these periods of light are sometimes warmer, sometimes cooler. Or why water pours from the sky from time to time. Or why, in the darkness, there are patterns of tiny white lights in the sky, together with a much larger pale white disc that seems to be slowly eaten away to nothing then replenished over a period of many ‘days’ and ‘nights’. What were these things, and why did the ‘air’ around us whizz by, sometimes with such force as to blow the trees down and blow our children off their feet and make them cry.

Canto: Hmm. Dogs and cats certainly don’t seem to wonder about such things. What about bonobos? They certainly display curiosity. I’ve seen monkeys crowd around an exotic animal, poking and prodding and jumping away when they get a reaction, just as I’ve seen the forest people of the Congo crowding around a white man, something completely new in their lives.

Jacinta: Yes isn’t the internet a grand thing for the armchair-bound. That sort of curiosity, as you say, is for new things, and it is on display in cats and dogs. And the questions for them are – can I eat it? Is it dangerous? But the queer regularities that have been with all these creatures from the beginning – night and day, warmth and cold, rain and shine, earth and sky – it seems unlikely that any dog or cat has felt curious about such things. Bonobos I’m not so sure about, but I’m doubtful. At some stage in our ancestry, and it would be obviously linked to neural development, we started asking ourselves – why is this happening?

Canto: Language. To ask these questions, even of ourselves, wouldn’t we need language?

Jacinta: Hmmm. Maybe. But imagine some highly irregular natural event, like a solar eclipse, being experienced by our pre-lingual ancestors, whether Homo erectus or an Australopithecine. They’d be shocked, scared, and they’d be hanging together, maybe huddling together, communicating their fear, and maybe their wonder.

Canto: Thinking mostly, is it dangerous? Should we hide? And even with language, with a singular event like that, they wouldn’t have an explanation.

Jacinta: Well, they might have a go at an explanation – okay, maybe you’re right, maybe some kind of language would be necessary, which is kind of the same thing as neural development. I mean, language clearly didn’t just come about, it evolved, over who knows how long. And we still don’t know if Neanderthals had it, or some rudimentary version of it, like us, 100,000 years ago or whatever. Think of fire. Once someone learned how to create and control it, and utilise it for warmth and to ward off predators, and, presumably later, to transform our food, they needed to communicate these skills. And from there, or somewhere, they might go on to communicate other things, like navigating by the stars, or how those stars crossed the sky, like human travellers crossing the land in search of food. Stories, of a kind.

Canto: So, I’ve been investigating a bit more, and there’s been some observed behaviours in chimps – and clearly they don’t have language, unless you define language very widely – that some have described as proto-ritual, such as slow-dancing in the face of fires. Fires caused by thunderstorms would be a highly irregular feature of life for chimps, living half in savannah grasslands, half in forests. And ‘dancing’, or ritual movements, might be a way of trying to placate or somehow communicate with this apparently living, dangerous force. And they’ve also been observed performing such ‘dances’ when the rain pours down.

Jacinta: Hmmm, and those movements might be meant to convey something to the fire or rain, or some other phenomenon, but also to other chimps. Something about communicating to others that there’s maybe a way to deal with these phenomena. This might hardly be in the realm of proto-proto religion, but surely the first religions were animistic – according significance and even some kind of intention to the wind and rain, thunder and lightning, lakes and streams, hills and valleys, specific trees and so on.

Canto: Yes, much fuss has been made of a tree hollow in which chimps were found placing stones, for no non-ritualistic purpose human observers could think of. If nothing else, it indicates that the more we observe other species, the more complex and multi-faceted they tend to become. Remember when we used to talk about bird-brains?

Jacinta: I also saw, on a video, that during a firestorm one of the chimps, apparently a king-pin, appeared to be raging at the fire, seeming to suggest that he – it would surely be a male, given chimp society – could, or thought he could, tame the beast, like old George slaying the dragon. Intimations of future shamanism?

Canto: Yes, or maybe he was just pissed off after a fight with the missus. Jane Goodall, on noting chimpanzees sitting for a long time staring ‘dreamily’ at a waterfall, used the term spirituality, which she roughly described as ‘the experience of appreciating magnificent, unknowable powers at work in the world beyond ourselves’. I believe Franz de Waal has used the term, in a different context, for bonobos too, but I’m not so comfortable with the term, it’s way too vague, and it drags religion behind it too emphatically. A feeling of awe, or wonder, of being overwhelmed, etc, can be described as just that.

Jacinta: And yet. A noisy, crushing, powerful waterfall, a raging, dangerous, painful fire – attributing something like intention to these things seems like a step forward. And also the desire for mastery of these forces, by somehow understanding and manipulating their intentions, that might seem an advance. But it’s hard to tell, with our smug hindsight.

Canto: And talking about hindsight, many of us consider, from the pinnacles of science, that religion is just a hangover from the days of pre-scientific explanations. Why are we here? Because the god called God created us to have dominion over the birds and bees and beasts of the field, and after a female was built from a male rib (which must’ve contained some pretty impressive pluripotent cells), and after some snakey female behaviour, we were sent forth out of Eden to multiply, and the god left us to our own devices, but when he came back from wheeling and dealing in foreign parts, he found we were wrecking everything – female trouble again, doubtless. And so he decided to drown us all, so as to Make his Arcadia Great Again, but, presumably feeling a bit tired of the creation process, he chose a human family and unspecified number of species to float about in a boat for a while, watching their friends and neighbours drowning, so as to begin it all again, but definitely for the last time, because, having discovered golf, he’d really lost interest.

Jacinta: Yes, that’s one variant, perhaps not the orthodox one, but as Mary Midgley used to say, these sorts of stories provide a far richer account of our origins than anything scientism has to offer. I mean, life from non-life in a warm puddle? Boring. 

Canto: But seriously, these creation stories, and ancilllary stories of the fruitful, deadly forests and the deserts and their oases, and the wind and the rain and storms and fevers and the patterned, watching stars and the smiling, burning sun, and the cool steadfast moon, these were as rich and comprehensive as they could possibly be, and those who remembered and told these stories best, and had the most intimate relations with all these insidious, ineluctable forces, would be precious persons indeed.

Jacinta: Mmmm. It’s a beginning.

References

https://www.theatlantic.com/science/archive/2016/03/chimpanzee-spirituality/475731/

 

creation stories – a critique and an appreciation

 

 

 

Written by stewart henderson

July 12, 2021 at 8:06 pm

how did life begin?: part 2 – RNA, panspermia, viroids and reviving the blob

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1280px-Difference_DNA_RNA-EN

Jacinta: So you’re going to talk about RNA, I know that stands for ribonucleic acid, and DNA is deoxy-ribonucleic acid, so – RNA is DNA without the oxygen?

Canto: Uhhh, you mean DNA is RNA without the oxygen.

Jacinta: Whatever, they’re big complex molecules aren’t they, but RNA is simpler, and less stable I think.

Canto: Okay, I’ll take it from here. We haven’t really known for very long that DNA is the essential material for coding and replicating life, and it’s a very complex molecule made up of four chemical bases, adenine, guanine, thymine and cytosine, better known as A, G, T and C. They connect to form base pairs, A always pairing with T and C with G.

Jacinta: What the hell are chemical bases? Do you mean bases as opposed to acids?

Canto: Well, yes. These bases, also called nucleobases, accept hydrogen ions, which have a positive charge. It’s all about pair bonding. The nucleobases – A, G, C and T, as well as uracil, found in RNA – are nitrogen-containing compounds which are attached to sugars… but let’s not get bogged down too much. The point is that DNA and RNA are nucleic acids that code for life, and most of the researchers chasing down the origin of life believe that RNA is a precursor of DNA in the process of replication.

Jacinta: And presumably there are precursors to RNA and so on.

Canto: Well presumably, but let’s just look at RNA, because we have a fair amount of evidence that this molecule preceded DNA as a ‘life-engine’, so to speak, and really no solid evidence, that I know of, of anything before RNA.

Jacinta: Okay so what is this evidence, and why did DNA take over?

Canto: Right, now the subject we’re entering into here is abiogenesis, the process by which life emerged from the inanimate. RNA is probably well down the chain from this emergence, but better to start with it than to dive into speculation. Now as you probably know, RNA has a single helical structure, and today it’s heavily involved in the process whereby DNA ‘creates’ proteins. In fact, all current life forms involve the action and interaction of three types of macromolecule, DNA, RNA and proteins…

Jacinta: But of course these complex molecules didn’t spring from nowhere.

Canto: Well we don’t know how they were built up, and many pundits think they may have been seeded here from elsewhere during the late heavy bombardment, which came to an end about 3.8 billion years ago, around the time that those Greenland rocks, with their heavy load of organic carbon, have been dated to. It seems plausible considering how quickly life seems to have taken off here.

Jacinta: Okay so tell us about RNA, how does it relate to the other two macromolecules?

Canto: Well, RNA is able to store genetic information, like DNA, and in fact it’s the genetic material for some of our scariest viruses, such as ebola, SARS, hep C, polio – not to mention influenza.

Jacinta: Wow, I didn’t know that. But one thing I do know about viruses is that they can’t exist independently of a host, so is RNA the basis of any truly independent life forms?

Canto: Not currently, on our planet, as far as we know, but the evidence is fairly strong that RNA has been central to life here from the very beginning, as it is still key to the most basic components of cells such as ribosomes, ATP and other co-enzymes. This suggests that RNA was once even more central, but in some areas it’s been subordinated to, and harnessed to, the more complex and recent DNA molecule. But, yes, since we can’t look at RNA coding for independent life-forms, we need to wind the clock back still further to look at precursors and other constituents of life, such as amino acids and peptides.

Jacinta: Which are chemical molecules, not biological ones. It seems to me we’re still a long way from working out the leap from chemistry to biology.

a peptide or amide bond - a covalent bond between two amino acid molecules

a peptide or amide bond – a covalent bond between two amino acid molecules

Canto: Yes, yes but we’re bridging various gaps. Peptides are created from amino acids, as you know. They are chains of amino acids linked by peptide bonds, and proteins are only distinguished from peptides in that they’re bigger versions of them, and bonded in a particular biologically useful way. You’ll notice when you read about this stuff that the terms ‘chemistry’ and ‘biology’ are used rather arbitrarily – a chemical compound can be referred to as a biological compound and vice versa. But various experiments have cast light on how increasingly ‘biological’ constituents are formed from simpler elements. For example, you may know that meteorites and comets, which bombarded the early earth in great numbers, contained plenty of amino acids – we’ve counted more than 70 different amino acids derived from meteorites, such as the Murchison meteorite that landed in Victoria in 1969. Another probable source of these amino acids, and even more complex and ‘biological’ molecules is comets, which also contain a lot of water in frozen form, but this has raised the question of how these molecules could have survived the impact of these colossal objects, which released enormous energy, some of them partially vaporising the earth’s crust. But an ingenious experiment, described in this video, and elsewhere, was able to simulate a comet’s impact, creating pressures many times greater than that experienced in our deepest oceans, to see what would happen to the amino acids. It was expected that they would barely survive the impact, but surprisingly they not only survived but forged bonds that created complex peptides.

a fragment of Murchison meteorite - of which there are many. This carbonaceous chondrite is still being analysed for organic compounds. Up to 70 amino acids identified so far

a fragment of Murchison meteorite – of which there are many. This carbonaceous chondrite is still being analysed for organic compounds. Up to 70 amino acids identified so far

Jacinta: Mmmm, that is interesting. So, the gap between peptides, or proteins, and RNA, what do we know about that?

Canto: Well, now you’re getting into highly speculative territory, but it’s certainly worth speculating about. Firstly, though, in trying to solve this origin of life problem, we have to note that the earth’s atmosphere was incredibly different from what it is now. In fact it was probably quite different from the way Haldane and Oparin and later Miller and Urey envisaged it. It was predominantly carbon dioxide, with hydrogen sulphide, methane and other unpleasant gases – unpleasant to us, that is. That, together with the continual bombardment from outer space has led some scientists to suggest that the place to find the earliest life forms isn’t the open surface but in hidden nooks and crannies or deep underground, in more protected environments.

Jacinta: Yeah the discoveries of so-called extremophiles has made that idea fashionable, no doubt, but presumably these extremophiles are all DNA-based, so I don’t see how investigating them will answer my question.

Canto: Okay, so it’s back to RNA. The thing is, I don’t want to go into the properties of RNA here, it’s just too complicated.

Jacinta: I believe it was Richard Feynman who said something like ‘to fully understand a thing you have to build it’. So there’s still this leap from polypeptides or proteins, which don’t code for anything, they’re just built by ribosomes – RNA structures – from DNA instructions, to sophisticated coded replicators. We have no idea how DNA or RNA came into being, and nobody has successfully created life apart from Doktor Frankenstein. So it’s all a bit disappointing.

Canto: You must surely be joking, or just playing devil’s advocate. You know very well that this is an incredibly difficult nut to crack, and we’ve made huge progress, new discoveries are being made all the time in this field.

Jacinta: Okay, impress me.

Canto: Well, only this year NASA scientists have reported that the nucleobases uracil, thymine and cytosine, essential ingredients of DNA and RNA, have been created in the laboratory, from ingredients found only in outer space – for example pyramidine, which they’ve hypothesised was first created in giant red stars – and they’ve found pyrimidine in meteors. So, another step towards creating life, and further evidence that life here may have been seeded from elsewhere. And if that doesn’t impress you, what about viroids?

Jacinta: Uhhh… what are they, viral androids? Which reminds me, what about the artificial intelligence route to creating life? Intelligent life, what’s more exciting.

Canto: Another time. Viroids are described as ‘sub viral pathogens’. We were talking about viruses before, as a kind of halfway house between the living and the lifeless, but really they’re much more on the side of the living. The smallest known pathogenic virus is over 2000 nucleobases long, and the biggest – well, a megavirus was famously identified just last year and revived after being frozen in Siberian permafrost for something like 35,000 years…

Jacinta: An ancient megavirus has been revived…? WTF? Who thought that was a great idea? Wait a minute, the Siberian permafrost, wasn’t that where Steve MacQueen and his mates dropped The Blob? Megadeath, not just a shite band! We’re doomed!

Canto: Well, strictly speaking it’s a virion, a virus without a host, which means it’s in a kind of dormant phase, like a seed. But I don’t want to talk about megaviruses, fascinating though they are – and very new discoveries. I want to talk about viroids, which are plant pathogens. They consist of short strands of RNA, only a few hundred nucleases long, without the protein coat that characterises viruses, and their existence tends to support the ‘RNA world hypothesis’. It was the discoverer and namer of viroids, Theodor Diener, who pointed out that they were vitally important macromolecules for explaining essential steps in the evolution of life from inanimate matter. That was back in 1989, but his remarks were ignored, and only rediscovered in 2014. So viroids are now a big focus in abiogenesis. They’ve even been called living relics of the pre-cellular RNA world.

Viroid

Jacinta: Okay, I’m more or less impressed. We’ll have to do more on abiogenesis in the future, it’s an intriguing topic, with more breakthroughs in the offing it seems. ..

 

 

Written by stewart henderson

September 28, 2015 at 11:23 pm