Posts Tagged ‘evolution’
group think revisited, or how to improve your mind
Confirmation bias (and the benefits of social reasoning) in a nutshell:
How can you say to your brother, ‘Brother, let me take the speck out of your eye,’ when you yourself fail to see the plank in your own eye? Luke 6: 42 New International Version
The argumentative theory of reason
The recent New Scientist collection, Being Human, includes an essay, ‘The argumentative ape’, by Dan Jones, which is worth reading and contemplating for any teacher involved in encouraging her students to think richly about current ethical or political issues. In my college, NESB students study ‘English for academic purposes’, which involves a lot of basic grammar and vocabulary at the lower levels, and academic presentations and essays at the higher levels. In these ‘discussion’ or ‘argument’ essays and presentations, students are required to examine the pros and cons of some chosen activity or decision, such as the proper driving age, the consumption of GM food, or even whether humanity has benefitted or blighted our planet.
However, there seems to be a contradiction in asking students to write, and be examined on, individually written ‘discussion essays’, when discussions and arguments are group rather than individual activities. More importantly, if we want to improve our students’ understanding of current issues, perhaps we should be placing more emphasis on group discussion than on individual analysis.
This is hardly a new idea. The ancient Athenians, founders of democracy – decision-making by the people – built their city around the agora, a gathering place for public talk and argument. This design was quite deliberate, as all Athenian citizens were required to contribute to discussions from which civic decisions were made.
‘The argumentative ape’, however, provides contemporary evidence about the evolutionary importance of argument in human society. It describes a thesis put forward by European researchers Hugo Mercier and Dan Sperber, that human reason evolved not so much to assist us in more clearly understanding our world, but to argue, to persuade, to convince others of our position, our right-ness. So, it evolved socially. And there appears to be some evidence for the more general ‘social brain’ hypothesis, in that a clear correlation has been found between the number of individuals in a primate group and the average brain size of that particular species.
Now one essential problem here should be obvious, as it was to Socrates in his battle with the sophists. The most persuasive arguments aren’t necessarily the best. So it’s natural that along with persuasiveness, skepticism would have developed, as humans sought to evaluate competing arguments.
Through scepticism we’ve identified many types of fallacious reasoning, and ways we have of convincing ourselves in the process of trying to convince others. Confirmation bias, or motivated reasoning, probably tops this list, as it is extremely pervasive if not universal. As Mercier points out, using confirmation bias seems counter-productive if you wish to arrive at correct results, for example in scientific research, but it can be highly effective in argument, as your bias commits you to garnering a multitude of arguments for your position while ignoring, and thus rendering insignificant, all arguments against. If we accept an argumentative theory of the evolution of reason, then, we will see confirmation bias not as a flaw, but as a device to strengthen our own arguments, and the ability to detect such biases would in turn be a device to undo or diminish the arguments of others.
how individual reasoning is affected by the larger group
Experimental psychologists have found many ways in which our reasoning can be affected or manipulated. Take, for example, the framing effect. It has been found, and regularly confirmed, that how the same problem is worded will affect our decision. Jones presents the scenario, used by psychologists, of a small village of 600 people threatened by a deadly disease. In scenario one, if Plan A is adopted, exactly 200 people will survive. If plan B is adopted, there will be a 1 in 3 chance that all will survive, and a 2 in 3 chance that none will survive. When this scenario is presented to subjects, the majority invariably choose Plan A. However when, in scenario two, Plan A is framed with the slight difference that exactly 400 people will die (with no change to Plan B), this is enough for the majority to flip over to Plan B. This consistent result has been explained in terms of ‘loss aversion’ – we prefer to avoid the explicit loss of life as expressed in the change to Plan A in scenario two. Significantly though for the argumentative ape hypothesis, this loss aversion bias is strengthened when we have to justify our decision to a larger group. We have a ready-made justification as expressed in the framing. It’s probable that we always have in mind what the larger group, or ‘society’ will think of our decision, but when this need to justify ourselves is made explicit, the ready rationalisation is more likely to be adopted.
Other effects of apparently faulty reasoning, such as the attraction effect and the sunk-cost fallacy, have been detected in psychological studies, and all have been shown to be enhanced when there is an explicit need for justification. The ‘argumentative’ thesis claims that we tend to choose the most easily justified option rather than what might be best.
Confirmation bias for me, scepticism towards you, and how it pans out
While this may seem a pessimistic outlook on our use of reason, the counterbalance lies in our ability, from clear evolutionary need, to identify and so counter the faulty arguments of others. This pattern follows a familiar evolutionary trajectory, in which a predator evolves a means to capture its prey, leading the prey to develop a defence mechanism to protect itself against the predator. Scepticism helps us to avoid being sucked in and ‘devoured’.
The result for group reasoning is that bias and the scepticism can balance each other out, leading to a greater recognition of the weaknesses in our own opinions and the strengths in those of others. And experimental evidence backs up this result. To quote from Jones’ article:
In one convincing study, psychologists David Moshman and Molly Geil at the University of Nebraska-Lincoln looked at performance in the Wason selection test – a simple card game based on logical deduction. When thinking about this task on their own, less than 10 per cent of people got the right answer. When groups of 5 or 6 people tackled it, however, 75 per cent of the groups eventually succeeded. Crucially for the argumentative theory, this was not simply down to smart people imposing the correct answer on the rest of the group: even groups whose members had all previously failed the test were able to come to the correct solution by formulating ideas and revising them in light of criticism (Thinking and Reasoning, vol 4, p 231).
He also points to research indicating that groups are more creative in their thinking than individuals (see sources below).
Implications for teaching, or how to best facilitate the best group thinking
Evidence from a series of studies by Anita Williams Woolley of Carnegie Mellon University in Pennsylvania suggests that a group’s individual skills are not the best predictor of the group’s overall performance in problem-solving. These studies were designed to measure the ‘collective intelligence’ of the group, in something like the manner of IQ tests for individuals. She found that those groups who scored highest were the most inclusive, allowing maximal participation within the group. Sensitivity to the moods and feelings of others helped groups to score highly, and the best groups were those with the greater number of female members, presumably because females have a greater social sensitivity.
Group thinking can, of course, backfire. Groupthink in fact has long been seen negatively, but this is because people with the same cognitive biases often congregate together, as with political parties and religious organisations, or gravitate towards similar professions, such as the police or the military. In such groupings it’s often the case that the group moves collectively to quite extreme positions. Where group thinking would be expected to work most effectively is precisely in a college for NESB students from different cultures and backgrounds, in which individuals are challenged by widely different but (hopefully!) cogent opinions.
As educators, we need to consider the best outcomes for our students. Clearly there is pressure, in an individualised results-based system, to push for individual skill in argumentation, with the resultant high test scores. However, the evidence for group interaction in improving students’ understanding of the many issues focused on in essays and seminars at the higher levels is clear. Of course the situation is complicated by the fact that many students at EAP2 and EAP3 levels still don’t have the grammatical and lexical skills to present cogent arguments in English, so that it’s often hard to determine whether their difficulties are those of reasoning or of language. Even so, I believe it is vital to take advantage of the cultural diversity of students’ experience and knowledge (even within identical language groups) to encourage interaction that will challenge biases and create awareness of a variety of perspectives. Hopefully this will enliven their thinking both within the college and in their studies beyond Eynesbury.
Some sources are found in the links. Here are others.
D Sperber and H Mercier,”Why do humans reason? Arguments for an argumentative theory”, Behavioural and brain sciences: Published online March 2011. http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1698090
http://edge.org/conversation/hugo_mercier-the-argumentative-theory. Mercer elaborates on the theory very interestingly in a video on this website
Williams Woolley, Anita, ‘Collective intelligence in human groups’, April 2012: Center for Collective Intelligence: http://cci.mit.edu/ci2012/plenaries/speaker%20slides%20ci%202012/Woolleyslidesci2012.pdf
D Moshman & M Geil, 1998 ‘Collaborative reasoning: evidence for collective rationality’. Thinking and reasoning V4 issue 3: http://www.tandfonline.com/doi/abs/10.1080/135467898394148
this one’s for the birds
Canto: If anybody doesn’t appreciate the beauty and complexity and general magnificence of birds they should pee off and never darken this blog again.
Jacinta: Right. Now what brought that on, mate?
Canto: Oh just a general statement of position vis-à-vis other species. Charles Darwin, an old friend of mine, was pretty disdainful of human specialness in his correspondence, but he kept a low profile – on this and everything else – in public. I want to be a bit more overt about these things. And one of the things that really amazes me about birds, apart from their physical beauty, is how much goes on in those teeny noggins of theirs.
Jacinta: Yes, but what really brought this on? I haven’t heard you rhapsodising about birds before.
Canto: You haven’t been inside my vast noggin mate. Actually I’ve been taking photos – or trying to – of the bird life around here; magpies, magpie-larks, crows, rainbow lorikeets, honeyeaters, galahs, corellas, sulphur-crested cockies, as well as the pelicans, black swans, cormorants, moorhens, coots and mallard ducks by the river, not to mention the ubiquitous Australian white ibis and the masked lapwing.
Jacinta: Well I didn’t know you cared. Of course I agree with you on the beauty of these beasties. Better than any tattoo I’ve seen. So you’re becoming a twitcher?
Canto: I wouldn’t go that far, but I’ve been nurturing my fledgling interest with a book on the sensory world of birds, called, appropriately, Bird sense, by a British biologist and bird specialist, Tim Birkhead. It’s divided into sections on the senses of birds – a very diverse set of creatures, it needs to be said. So we have vision, hearing, smell, taste, touch, and that wonderful magnetic sense that so much has been made of recently.
Jacinta: So we can’t generalise about birds, but I know at least some of them have great eyesight, as in ‘eyes like an eagle’.
Canto: Well, as it happens, our own Aussie wedge-tailed eagle has the most acute sense of vision of any creature so far recorded.
Jacinta: Well actually it isn’t ours, it just happens to inhabit the same land-form as us.
Canto: How pedantic, but how true. But Birkhead points out that there are horses for courses. Different birds have vision adapted for particular lifestyles. The wedge-tail’s eyes are perfectly adapted to the clear blue skies and bright light of our hinterland, but think of owl eyes. Notice how they both face forward? They’re mostly nocturnal and so they need good night vision. They’ve done light-detection experiments with tawny owls, which show that on the whole they could detect lower light levels than humans. They also have much larger eyes, compared with other birds. In fact their eyes are much the same size as ours, but with larger pupils, letting in more light. They’ve worked out, I don’t know how, that the image on an owl’s retina is about twice as bright as on the average human’s.
Jacinta: So their light-sensitivity is excellent, but visual acuity – not half so good as the wedge-tailed eagle’s?
wedge-tailed eagle – world’s acutest eyes
Canto: Right – natural selection is about adaptation to particular survival strategies within particular environments, and visual acuity isn’t so useful in the dark, when there’s only so much light around, and that’s why barn owls, who have about 100 times the light-sensitivity of pigeons, also happen to have very good hearing – handy for hunting in the dark, as there’s only so much you can see on a moonless night, no matter how sensitive your eyes are. They also learn to become familiar with obstacles by keeping to the same territory throughout their lives.
face of a barn owl – ‘one cannot help thinking of a sound-collecting device’, quoth researcher Masakazu Konishi
Jacinta: So they don’t echo-locate, do they?
Canto: No, though researchers now know of a number of species, such as oilbirds, that do. Barn owls, though, have asymmetrical ear-holes, one being higher in the head than the other, which helps them to pinpoint sound. It was once thought that they had infra-red vision, because of their ability to catch mice in apparently total darkness, but subsequent experiments have shown that it’s all about their hearing, in combination with vision.
Jacinta: Well you were talking about those amazing little brains of birds in general, and I must say I’ve heard some tales about their smarts, including how crows use cars to crack nuts for them, which must be true because it was in a David Attenborough program.
Canto: Yes, and they know how to drop their nuts near pedestrian crossings and traffic lights, so they can retrieve their crushed nuts safely. The genus Corvus, including ravens, crows and rooks, has been a fun target for investigation, and there’s plenty of material about their impressive abilities online.
seeing is believing
Jacinta: So what other tales do you have to tell, and can you shed any light on how all this cleverness comes in such small packages?
Canto: Well Birkhead has been studying guillemots for years. These are seabirds that congregate on cliff faces in the islands around Britain, and throughout northern Europe and Canada. They’re highly monogamous, and get very attached to each other, and thereby hangs another fascinating tale. They migrate south in the winter, and often get separated for lengthy periods, and it’s been noted that when they spot their partner returning, as a speck in the distance, they get highly excited and agitated, and the greeting ceremony when they get together is a joy to behold, apparently – though probably not as spectacular as that of gannets. Here’s the question, though – how the hell can they recognise their partner in the distance? Common guillemots breed in colonies, butt-to-butt, and certainly to us one guillemot looks pretty well identical to another. No creature could possibly have such acute vision, surely?
Jacinta: Is that a rhetorical question?
Canto: No no, but it has no answer, so far. It’s a mystery. It’s unlikely to be sight, or hearing, or smell, so what is it?
Jacinta: What about this magnetic sense? But that’s only about orientation for long flights, isn’t it?
Canto: Yes we might discuss that later, but though it’s obvious that birds are tuned into their own species much more than we are, the means by which they recognise individuals are unknown, though someone’s bound to devise an ingenious experiment that’ll further our knowledge.
Jacinta: Oh right, so something’s bound to turn up? Actually I wonder if the fact that people used to say that all Chinese look the same, which sounds absurd today, might one day be the case with birds – we’ll look back and think, how could we possibly have been so blind as to think all seagulls looked the same?
Canto: Hmmm, I think that would take a lot of evolving. Anyway, birds are not just monogamous (and anyway some species are way more monogamous than others, and they all like to have a bit on the side now and then) but they do, some of them, have distinctly sociable behaviours. Ever heard of allopreening?
Jacinta: No but I’ve heard the saying ‘birds of a feather flock together’ and that’s pretty sociable. Safety in numbers I suppose. But go on, enlighten me.
Canto: Well, allopreening just means mutual preening, and it usually occurs between mates – and I don’t mean in the Australian sense – but it’s also used for more general bonding within larger groups.
Jacinta: Like, checking each other out for fleas and such, like chimps?
Cant: Yeah, though this particular term is usually reserved for birds. Obviously it serves a hygienic purpose, but it also helps calm ruffled feathers when flocks of colonies live beak by jowl. And if you ever get close enough to see this, you’ll notice the preened bird goes all relaxed and has this eyes half-closed, blissed-out look on her face, but we can’t really say that coz it’s anthropomorphising, and who knows if they can experience real pleasure?
Jacinta: Yes, I very much doubt it – they can only experience fake pleasure, surely.
Canto: It’s only anecdotal evidence I suppose, but that ‘look’ of contentment when birds are snuggling together, the drooping air some adopt when they’ve lost a partner, as well as ‘bystander affiliation’, seen in members of the Corvus genus, all of these are highly suggestive of strong emotion.
Jacinta: Fuck it, let’s stop beating about the bush, of course they have emotions, it’s only human vested interest that says no, isn’t it? I mean it’s a lot easier to keep birds in tiny little cages for our convenience, and to burn their beaks off when they get stressed and aggressive with each other, than to admit they have feelings just a bit like our own, right? That might mean going to the awful effort of treating them with dignity.
Canto: Yyesss. Well on that note, we might make like the birds and flock off…
how the flock do they do that?
how did life begin?: part 2 – RNA, panspermia, viroids and reviving the blob
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
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
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.
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. ..
how did life begin? part 1 – Greenland rocks, warm little ponds and unpromising gunk
the basics of the Miller-Urey experiment: sparking interest
Jacinta: Well, we need an antidote to all that theological hocus-pocus, so how about a bit of fundamental science for dummies?
Canto: Sounds great, I just happened to read today that there are three great questions, or areas of exploration for fundamental science. The origin of the universe – and its composition, including weird black holes, dark matter and dark energy – that’s one. The others are the origin of life and the origin of consciousness. Take your pick.
Jacinta: I’ll choose life thanks.
Canto: Not a bad choice for a nihilist. So life has inhabited this planet for about three and a half billion years, or maybe more, while the planet was still cooling from its formation…
Jacinta: Isn’t it still doing that?
Canto: Well, yes of course. An interesting study conducted a few years ago found that around 54% of the heat welling up from within the earth is radiogenic, meaning that it results from radioactive decay of elements like radium and thorium. The rest is primordial heat from the time of the planet’s coalescing into a big ball of matter.
Jacinta: Gravity sucks.
Canto: Energetically so.
Jacinta: You say three and a half billion years or more – can you be a bit more specific? Are we able to home in on the where and the when of life’s origin on this planet?
Canto: Well, that would be the pot of gold, to locate the place and time of the first homeostatic replicators, to wind back history to actually witness that emergence, but I suspect there would be nothing to actually see, at least not on the time-scale of a human life. I think it’d be like the emergence of human language, only slower. You’d have to compress time somehow to witness it.
Jacinta: Fair enough, or maybe not, it seems to me that the distinction between the animate and the inanimate would be pretty clear-cut, but anyway presumably scientists have a time-frame on this emergence. What allows them to date it back to a specific time?
Canto: Well, it’s an ongoing process of honing the techniques and discovering more bits of evidence, a bit like what has happened with defining the age of our universe. For example, you’ve heard of stromatolites?
Jacinta: Yes, those funny black piles that stick out of the water and sand, somewhere in Western Australia? They’re made from really old fossilised cyanobacteria, right?
Canto: Well, that’s a start, they’re rather more complicated than that and we’re still learning about them and still discovering new deposits, all around the world, both on the shoreline and inland. But the Shark Bay stromatolites in WA were the first to be identified, and that was only in 1956. More recently though, there’s been an entirely different discovery in Greenland that’s raised a lot of excitement and controversy…
Jacinta: But hang on, these stromatolites, they say they’re really old, like more than 3 billion years, but how do they know that? As Bill Bryson would say.
Canto: Well, good question Jass, in fact it’s highly relevant to this Greenland discovery so let me talk about radiometric dating, using this example. Greenland has been attracting attention since the sixties as a potential mineral and mining resource, so the Danish Geological Survey was having a look-see around the region of Nuuk, the capital, in the south-west of the island. The principal geologist found ten successive layers of rock in the area, using standard stratigraphic techniques that you can find online, though they’re not always easy to apply, as strata are rarely neatly horizontal, what with crustal movements, fault-lines and rockfalls and erosion and such. Anyway, it was his educated guess that the bottom of these layers was extremely old, so he sent a sample to Oxford, to an expert in radiometric dating there. This was in about 1970.
Isua rocks, Greenland. Oldest rocks discovered, showing plausible traces of 3.8 billion-year-old life
Jacinta: And doesn’t it have to do with radioactive isotopes and half-lives and such?
Canto: Absolutely. Take uranium 238, which if you’ve been watching the excellent recent ABC documentary you’ll know that it decays through a whole chain of, from memory, twelve nuclides before stabilising as an isotope of lead. That decay has a half-life of 4.5 billion years – longer than the life of this planet, or at least the life of its crust. So it’s a matter of measuring the ratio of isotopes, to see how much of the natural uranium has decayed. In this case, the gneiss, the piece of bottom-strata rock that was analysed, had the highest proportion of lead in it of any naturally occurring rock ever discovered.
Jacinta: So that means it’s likely the oldest rock? Aw, I thought Australia had the oldest. This is terrible news.
Canto: No time to be parochial when the meaning of life is at stake. May I continue? So this was an exciting discovery, but more was to come, and it’s continuing to come. The geological team were inspired to continue their explorations around the Godthaab Fjord in Greenland, and found what are called ‘mud volcanoes’, pillows of basaltic volcanic lava that had issued out into the seawater. These were again dated at about 3.7 billion years old, and this strongly suggested the existence of warm oceans at that time, with hydrothermal vents such as those recently discovered to be teeming with life…
Jacinta: Right, so that might be pushing the age of life back a few hundred million years, if it can be verified, but it still doesn’t answer the how question..
Canto: Oh, nowhere near it, but I’ve just started mate. May I continue? Not surprisingly this region is now seen as a treasure trove for those hunting out the first life forms and trying to work out how life began. It was soon found that the Isua greenstone to the north of Nuuk contains carbon with a scientifically exciting isotopic ratio. The level of carbon 13 was unexpectedly low. This is generally an indication of the presence of organic material. Photosynthesising organisms prefer the lighter carbon 12 isotope, which they capture from atmospheric or oceanic carbon dioxide. But the finding’s controversial. Many are skeptical because this is the period known as the ‘late heavy bombardment’, with asteroids crashing and smashing and vaporising and possibly even sterilising… and they haven’t discovered any fossils.
Jacinta: So, photosynthesis, that’s what created the great oxygenation, which created an atmosphere for complex oxygen-dependent organisms, is that right?
Canto: Well, that was much later, and it’s a vastly complex story with quite a few gaps in it, so maybe we’ll save it for future conversations…
Jacinta: Okay, fine, but couldn’t one of those asteroids have brought life here, or proto-life, or the last essential ingredient…?
Canto: Yes, yes, maybe, but you’re distracting me. May I please continue? Where was I? Okay, so let’s look at the various theories put forward about the origin of life – and it will bring us back to Greenland. You’ve mentioned one, called panspermia. That’s the idea that life was seeded here from space, maybe during the heavy bombardment…
Jacinta: Which isn’t an adequate explanation at all, because where did that life come from? I want to know how any life-form anywhere can spring from the inanimate.
Canto: Yes all right, don’t we all smarty-pants? One of the most interesting early speculators on the subject was one Charles Darwin, who wrote – very famously – in a letter to his good mate Joseph Hooker in 1871, and I quote:
It is often said that all the conditions for the first production of a living organism are now present, which could ever have been present.— But if (& oh what a big if) we could conceive in some warm little pond with all sorts of ammonia & phosphoric salts,—light, heat, electricity &c present, that a protein compound was chemically formed, ready to undergo still more complex changes, at the present day such matter wd be instantly devoured, or absorbed, which would not have been the case before living creatures were formed.
Now this was pretty damn good speculation for the time, and a couple of generations later two biologists, Aleksandr Oparin of Russia and John Haldane of England, independently developed a hypothesis that built on Darwin’s ideas.
Jacinta: Oh yes, they had this idea that if you added a bit of lightning to the early terrestrial atmosphere, which was full of ammonia or something, you’d get a lot of organic chemistry happening.
Canto: Well I think the ‘or something’ part is true there – their idea was that there was a lot of hydrogen, methane and water vapour in the early atmosphere, and that, combined with local heat caused perhaps by lightning, or volcanic activity or some sort of concentrated solar radiation, the combo created a soup of organic compounds, out of which somehow over time emerged a primordial replicator.
Jacinta: So far, so vague.
Canto: Okay, I’m just getting started. The Oparin-Haldane hypothesis was highly speculative, of course. The point being made was that this key event was all that was needed for natural selection to kick in. This replication must have been advantageous, and of course over time there would’ve been mutations,with the mutants competing with the originals, and the winners would’ve been the most efficient and effective harvesters of resources, and there would’ve been expansion and more mutations and modifications and so forth. And out of that would come the first self-sustaining homeostatic environment, the proto-cell, within which more sophisticated machinery for processing resources could be developed…
Jacinta: Okay so you’ve more or less succeeded in dissolving the boundary between the animate and the inanimate before my eyes, but it’s still pretty vague on the details.
Canto: In 1953, Stanley Miller took up the challenge of his supervisor, famous Nobel Prize-winning biologist Harold Urey, who noted that nobody had tested the Oparin-Haldane hypothesis experimentally. Miller created a mini-atmosphere in a bottle, using methane (CH4), hydrogen, water vapour and ammonia (NH3), and after sparking it up for a while, he managed, to the amazement of all, to produce amino acids, the building blocks of proteins. Surely the first step in producing life itself.
Jacinta: Ah yes, that was a famous experiment, but didn’t it turn out to be something of a dead end?
Canto: Well, yes and no. It has been replicated with different mixtures and ratios of gases, and amino acids, sugars and even traces of nucleic acids have been generated, but nothing that could be described as a primordial replicator. But of course this work has got a lot of biologists thinking.
Jacinta: But this was 60 years ago. That’s a lot of thought without much action.
Canto: Well, what has since been realised about the experiments of Miller and others is that they create an enormous complexity of organic molecules in a rather uncontrolled way, a kind of chemical gunk similar to what might be created when you burn the dinner. The point being that when you burn the dinner – which is something necessarily organic like a dead chook, or pig, or tragically finless shark or whatnot…
Jacinta: Or a pumpkin, or Nan’s rhubarb pie..
Canto: Yeah, okay – you get this messy complexity, all mixed with oil and vinegary acids and shite – you get this break-down into gunk, and that’s easy. What’s hard is to go in the other direction, to build up from gunk into a fully fledged chicken, or a handsomely finned shark. And that’s what these experiments were trying to do, in their small way. They were creating this primordial-soup-gunk and hoping, with a bit of experimental help, to spark life into it, and basically getting nowhere. The problem is essentially to do with randomness and order. How do we get order out of random complexity? It’s easy to go the other way, for example with explosions and machine guns and such. We see that everywhere. But building the kind of replicating order that you find even in mycoplasma, the smallest genus of bacteria, from scratch, and by chance – well, that’s mind-bogglingly improbable.
mycoplasma, one of the simplest life forms – but try making one from scratch
Jacinta: So we have to think in terms of intermediate stages.
Canto: Yes, well, there are big problems with that, too… But let’s give it a rest for now. Next time, we’ll discuss the RNA world that most biologists are convinced preceded and helped create the DNA world we live in.
N B – This piece owes much to many, but mainly to Life on the edge: the coming of age of quantum biology, by Jim Al-Khalili & Johnjoe McFadden
some thoughts on urbanisation, language and culture
Australian language families. From west to east:
Pama–Nyungan (3 areas)
The trend is massively towards urbanisation, though it varies massively between nations. The big urbanising country now is China of course. Citification leads to homogenisation, as everyone strives to be original. Anthropologist Wade Davis says that of the 7,000 or so extant languages, more than half are not being taught to the next generation. Cities are about communication, requiring a common language. It’s unlikely to be Wajarri or Pitjantjatjara. How about English? Language groups, it has been argued, constitute the most natural nations, rather than states with their artificial boundaries. There’s a whole theory based around this but I say, whenever you hear the word natural you should be skeptical. Why did a diversity of languages arise? A very very complex question. Or rather a simple question but the answer…
It presumably wasn’t the case that each language was invented from scratch. My speculation – somewhere, sometime, a human or proto-human population developed a language (a bit like saying ‘here, a miracle happens’, but we know more than that about the earliest abstract sign systems). That population grew, split up and separated to such distances that the languages followed separate developments, just like, say, chimps and bonobos followed separate lines of development after being separated by the Congo River, if that’s what happened. But then it could have been invented from scratch more than once, as is supposed to have been the case with writing.
Surely though the emergence of all these languages is primarily due to migration and isolation. Surely this is neither natural or unnatural. It happens. The loss of many of these languages will be due to their being surplus to requirements, due to a modern process that has reversed the ‘tyranny of distance’. The need to communicate effectively across distances, between nations, has meant that a lingua franca has been a high priority, and the more such a language dominates, economically and culturally, the more small, local languages will die of neglect, or be rendered redundant. Is this tragic? I’m not entirely sure.
Wade Davis is quoted (in issue 63 of Cosmos magazine) as saying:
The central revelation of anthropology is that other peoples of the world are not failed attempts at being you, at being modern. On the contrary they are unique answers to a fundamental question: what does it mean to be human and alive? And when the peoples of the world answer that question they do so in 7000 different voices, and those voices and answers collectively become our human repertoire for dealing with the challenges that will confront us all. When we lose a culture we lose a part of ourselves. And it doesn’t have to happen.
This is all stirring stuff, and it would seem bad form to demur, even slightly. But I would like to reflect a bit more on this. First, note that Davis is equating language with culture, which is fair enough to a degree, but some people may be separated by language but have more cultural similarities than differences. After all, this is part of the raison d’être of the European Union, that the French, the Italians, the English etc have enough in common that they should work together rather than separately. And I would dispute the claim that there are 7000 different voices answering the basic questions of human existence and purpose. Surely there are no less than 7.2 billion? On my street, I know there are at least a couple of people who speak a different first language from me. It’s highly likely, though, that I would share more with them in terms of outlook or interest than with others who share my language. But I wouldn’t share every interest or preoccupation with anyone, and nor would anyone else.
And to look at the first part of the quote: I’ve never seen other cultures, such as Australian Aboriginal cultures, as failed attempts at being modern. I see them as generally quite successful attempts at surviving and multiplying in a fairly inhospitable but obviously not uninhabitable environment, in which they’ve had to adapt to a world of resources, opportunities and threats that has remained relatively static, and certainly far far more static than was the situation in Europe over the same time period. And then, 200-odd years ago, Europeans arrived here, with (always in hindsight!) predictable consequences. The very concept of modernity would not have occurred to humans who had lived in a pretty well completely unchanging environment for more than 40,000 years, whereas for the Europeans who arrived here the concept of modernity was very much a living thing, as they were constantly aware of their changes and development, in technology, in politics, in lifestyle. They naturally believed in the progress which had, after all brought them to this great southern land and enabled them, they felt, to lay claim to it.
So, many of us are well aware of the situation. Just keeping to our Australian circumstances (though I’m actually a Brit, if it comes to strict definitions), one culture or set of cultures was long habituated to stasis, the other set of cultures was long habituated to dynamics, and, as a result of having survived all those dynamic processes, to ‘progress’. So, in an important sense these two different groups aren’t answering the one fundamental question, they’re answering two quite different questions. The Aborigines had answers to ‘what is it like to be a human in a world which for 40,000 years has been unchallenged by other humans, and which has enough resources to survive on if you know how to read the signs, and if you pass knowledge and skills on down the generations’, whereas the Europeans had answers to ‘what is it like to be a human whose ancestors have fought and defeated invaders, conquered other lands and enslaved or exploited their peoples, cultivated soils and experimented with plants and animals to provide a variety of foodstuffs, exploited mineral resources for construction and technological purposes, etc etc’.
So, it comes to this. We Europeans, sharpened by our historical experience, have come to Australia and transformed it. We – some of us – tried to make peace with the Aborigines while taking the best land to cultivate ourselves. We brought in our sheep and cattle, we took over the rich coastlines, we built our industries, and we made an assumption of ‘Terra nullius’ because it was so obviously in our interest to do so. We had no idea, of course, of the history of the Aborigines – being all ‘young earth creationists’ at the time. The Aborigines had no more chance than, say, a tasty flightless bird would have if feral cats were introduced onto an island that the birds had comfortably and skilfully survived on for a million years. Of course we didn’t eat any Aborigines (as far as I’m aware) but we transformed their environment almost beyond recognition and made a continuation of their habitual way of life well-nigh impossible.
I make that comparison to suggest that humans are nothing special. Cultures, like species, go extinct, or adapt. That’s a harsh reality, but somehow, in our sophistication, we know, at least some of us do, that diversity, of species and cultures, is a good thing, not just intrinsically but for our own selfish benefit. It’s a balance maybe – we strive to preserve, but also encourage to adapt.
why is evolution true? (if it is): part two, the problem of macroevolution
So, in Darwin’s day, there was a clear problem. Fossilised bones turning up everywhere, sometimes of gigantic creatures unlike anything on earth, sometimes of creatures very like those then living but not quite the same – in any case all indicating change, change, change. And there were many other oddities, some of them observed by Darwin himself on his Beagle voyage. Marine fossils embedded in landscapes way above sea level. Darwin had a great interest in geology, courtesy of Charles Lyell, whose landmark work, Principles of Geology, he carried with him on his great voyage. He was very interested in Lyell’s view, derived from Hutton, that landscapes changed slowly, with mountains rising from the sea, over periods of time much greater than the biblical account. So imagine his mind, full of Lyell’s speculations, when on March 4 1835 he was exploring the cliffs above Talcuhano Harbour, near Concepcion in Chile, shortly after the devastating earthquake, and found maases of seashells embedded in the rock. The Andes had risen from the sea, surely! Yet he might well have been in two minds – slow change, yes, perhaps, but the earthquake had also changed the physical landscape in an instant, bringing rocks dripping and oozing with marine life up several feet above the sea surface…
Meanwhile, dinosaurs. Of course the bones of these critters have been unearthed for millenia, but it was only in the early nineteenth century that they were treated scientifically. It was Richard Owen, later to become Darwin’s bête noir, who coined the term in 1842 (it’s from the Greek, roughly meaning ‘terrible lizard’ though dinos weren’t lizards, and they weren’t all terrible, or terribly large). These huge beasts (dinos come in all sizes, but large bones are more easily preserved than small ones, giving a false picture, and of course bigness grabs the public imagination) had clearly disappeared, but when? Why? How long ago? It all made the question of the earth’s actual age and history rather more urgent.
Darwin, back in England after a richly stimulating voyage in which he’d collected and ruminated over a vast number of exotic species, was exercised by a number of problems. Why did whole species disappear? Surely this had some connection with changes of landscape and habitat? He’d been making observations with regard to predators and prey, how species depended on other species, how individuals competed for mates. It seems that, unlike Wallace who came upon the insight of natural selection more or less in one fell swoop years later, Darwin was piecing things together painfully slowly, with hesitation, scepticism and uncertainty, but also with a dogged accumulation of evidence, so that when, finally, impelled by the famous letter from Wallace in the late 1850s to express his views, he was able to do so fulsomely, in spite of a lack of writerly ability. And the rest, as they say, is history.
The theory of natural selection is the most spectacularly successful and productive theory in biology, and is in fact its foundation stone. It has been reinforced by all that has been discovered since, especially in genetics and microbiology, fields that didn’t exist in Darwin’s time. The basis of the theory is quite simple, though it has been much misrepresented. Creatures reproduce, and generally the offspring are pretty well identical to the parents, but sometimes mutations occur. The offspring is in some way different. Usually the difference is ‘negative’, disadvantaging the offspring. The offspring is thus unable to reproduce and its line dies out. Sometimes the difference is ‘neutral’ and the line continues to reproduce, until or unless natural (environmental) conditions change and that line becomes either positive or negative within the context of those conditions. In other words it thrives compared to others or it dies out. Sometimes the difference is immediately positive, and this line outcompetes the others. The variation is random, but the natural environment ‘selects’ the best fit – the birds with the best beak for pecking out food; the worms with the best chemistry for thriving in a particular soil; in more recent times, the bacteria that can best resist the antibiotics we throw at them.
So the theory of natural selection describes incremental, gradual change. Its effect upon species is more difficult to explain, and it’s with this that creationists like to play, raising lots of dust and fog with respect to the species concept.
So what exactly is a species? The first more or less universally accepted classification of living things into groups was that of Linnaeus in his Systema naturae of 1735. It was a thoroughgoing system, from kingdom at the top, ranging down through phylum, class, order, family, genus and species. It’s still used today, of course, with various additions intercalated with these layers, but in the 20th century a new taxonomic system called cladistics, based on a more scientific understanding of descent from common ancestry, and so incorporating the new science of genetics, has won increasing favour.
One of the main reasons for this new development is that the term ‘species’ has historically been frustratingly vague. Originally it was based on morphological characteristics – in other words, visible similarities. Nowadays, though, with the emergence of population genetics and genomics, we can be more rigorous about species and speciation. Basically, a species becomes separated from another when it no longer breeds with that other. More often than not, this is due to geographic separation. Early on in the separation interbreeding is still possible, but over time, with continued lack of opportunity, the two groups become increasingly distinct and unlike (and one or both groups may go extinct). This branching has of course occurred oodles of times, creating an evolutionary bush, each twig of which can be traced back to the original stem.
So far, so clear, I hope. So where do the creationist terms micro-evolution and macro-evolution come in? Well, off the top of my head, I think that, since creationists really really dislike the theory of natural selection as presented by Darwin, they have to account for obvious changes somehow without abandoning divine creation, especially of humans, as soul-blessed, dominion-holding, image-of-god types. So, they distinguish micro-evolution, changes within species (e.g. different breeds of dogs) from macro-evolution, transformations from one species to another, which they claim doesn’t exist. Presumably they think that every species was specially created by their god, though why he should have created so many and rendered the vast majority of them extinct before humans even came on the scene is a mystery. This points up a major problem for those who believe in directed evolution as well as creationism.
Okay, to be clear, micro-evolution and macro-evolution aren’t terms invented by creationists, though they’ve taken to them like babies to their mothers’ milk. The terms were first used by evolutionary biologists early in the 20th century to characterise not different processes but different scales of evolution. Micro-evolution plus time (in which minute changes accumulate) equals macro-evolution. Creationists, then, are reduced to claiming that, because we don’t ‘see’ speciation, it doesn’t exist. Presumably they can say the same for the big bang and black holes, but we can detect such objects and events through increasingly precise instrumentation, and we can pretty well map the relations between species, and the branchings-off, by examining genomes. They tell us, for example, that we share an ancestor with our closest living relatives, the chimps and bonobos, dating back between 5 and 7 million years ago. We are equally related to these two species because they branched off from each other later, between one and a half and two million years ago. Richard Dawkins, in his monumental work The Ancestors’ Tale, attempted to trace these nodes of connections between the ancestors of humans and other species, back to the first life forms. There are gaps in our knowledge of course, but they’re being filled in on an almost daily basis.
As Dawkins points out in another of his books, River out of Eden, the DNA ‘revolution’ that got underway as a result of Watson and Crick’s unravelling of the molecular structure of the gene, is a digital revolution. The genetic code is quaternary, with four nucleotide elements – adenine, thymine, cytosine and guanine which can be combined in specific ways. Therefore the difference in the coding for different proteins, leading on the large scale to all the variation we see, can be worked out mathematically. This allows us to define more precisely our cousinship to other species – which are the more distant cousins, horses or pigs? Or, how closely connected are bees and butterflies? We can illustrate these relations using cladograms:
The technology we now have at our disposal allows us to map whole genomes increasingly cheaply and efficiently, and so we’re finding some surprising relationships. For example, recent DNA analysis has revealed that falcons, previously thought for fairly obvious reasons to be closely related to other birds of prey such as eagles, are in fact more closely related to parrots, songbirds and passerines such as the humble sparrow – a significant shift in taxonomic placement.
The obvious connections between species, and the fact that we can draw the evolutionary bush with increasing confidence, makes a mockery of creationist claims against natural selection, which not only explains speciation but also extinction. We may not know exactly why the neanderthals, or the trilobites, or the Australian megafauna died out, but natural selection points us in the right direction for answers – climate change, food scarcity and the introduction of new predators into the environment being the obvious candidates. The creationist, on the other hand needs to answer the question – why would their god keep creating these species, endlessly, only to have them snuffed out? No answers about the opacity of their god’s intentions are acceptable. And of course that’s far from being the only question they can’t answer.
why is evolution true? (if it is): part one, the problem of fixity
some Galapagos finches
Much of my writing, especially about sciency stuff, is an attempt to own the knowledge. It’s perhaps never completely successful, especially for the non-specialist, the dilettante, who tries to own so much and to keep all those possessions together. You read about it, you cast it in your own words, you grasp it, you think you’ve grasped it completely, you move on to other things, and six months later you’re asked a curly question and in trying to answer it you find you’ve forgotten the half of it, and you wonder – did I ever really understand it after all?
So. We have the theory of evolution, or natural selection from random variation, and we have the theories of special and general relativity and quantum theory and so forth. And we have those in science who tell us that ‘theory’ is a technical term constantly misunderstood by the general public and deliberately misconstrued by those with particular agendas. And we have general talk and a lot of general ignorance about evolution.
Several years ago, when I was starting out as a teacher of ESOL (English to speakers of other languages) I observed a small community centre English class. The elderly teacher was asked by a well-dressed middle-aged African man, did she really think evolution – that we were descended from monkeys – was true? It was a polite, puzzled question. The teacher, understandably not wanting to dive down that rabbit hole, replied, ‘well, you know, it’s just a theory’, and the subject was changed. It unsettled me, to put mildly. It’s not how I would’ve dealt with the matter, and in fact I’ve twice since been placed in that position in recent times, and I’ve responded with ‘oh yes, it’s true, the evidence is in and it’s overwhelming,’ or words to that effect. Bam bam, take that and let’s back to grammar.
But of course, that response, too, is unsettling. After all, I could’ve given the exact same response to the question ‘Does God exist?’. It was just saying, an argument from my own authority.
Of course I had back-up from years of science and evolution-reading, but still I felt I was just imposing my authority as a teacher. I half-hoped for and half-dreaded being asked to elaborate.
The other night, at an atheist meet-up, the group was ‘invaded’ by three or four young street-preachers, self-confessed fundies who were apparently keen to debate evolution (they didn’t believe in it) and cosmology (the universe can’t create itself, ergo god). I didn’t engage with them myself, as I’m still recovering from a chest infection and want to avoid stress, but things got very heated over in their corner and I’ve since received an email asking for help to convince one of them of the evidence for evolution. It may be that the young man’s ignorance is wilful, but maybe not, and in any case it provides me with a useful opportunity to answer as best I can the title question.
Questions were raised about the fixity of species well before Charles Darwin was born. The most important figures in this early questioning of orthodoxy came from France. One of the founders of naturalism, Buffon, speculated that the earth might be much older than the standard biblical 6000 years, and that change, both geological and organic, might be endemic and constant. He mostly kept his views to himself, as the idea that the earth was maybe more than ten times older than the accepted figure was incendiary for the time. Lamarck, however, was the first to really go public with a theory of evolution. His essential view was that creatures adapted to their environment over time through the inheritance of acquired characteristics. Although he was generally incorrect as to his mechanism there is still some interest in his ideas today, but above all Lamarck strongly influenced future thinking on the subject as he was a first-rate scientist.
It should be noted though that all this speculation was brought on by the problems posed by evidence. The biblical fixity of species account was becoming increasingly difficult to reconcile with the discoveries of fossils of creatures not to be found anywhere, yet apparently related to current species. And then there were the fossils of ‘giants’, which had been discovered here and there for centuries, but which were not described scientifically until the nineteenth century. How could all these remains of ‘disappeared’ creatures be turning up in a world where creation was fixed? The most popular explanation was ‘catastrophism’, a view held by Cuvier, a younger contemporary of Lamarck and one of his strongest critics. It was an attempt to reconcile fixity with a conveniently biblical diluvian view, but it continued to move thinking in a scientific, evidence-based direction.
Meanwhile, however, other fields of research, such as geology, were also becoming increasingly scientific, especially in Britain, with the work of Hutton and Lyell. Through inference from present conditions, they developed a gradualist, uniformitarian theory of physical change, with a more open-ended view of the earth’s age. This was the scientific background to Darwin’s naturalism. His own grandfather, Erasmus, dabbled in evolutionary ideas, and proposed that the earth had existed for ‘millions of ages’.
Now I know there’s a view out there among fundamentalists called ‘young earth creationism’, but I don’t know much about it. It would seem to be an absolutely crackpot notion, a denial of modern geology, astronomy and cosmology as well as biology and palaeontology, and I presume people who think this way consider the whole of modern science a massive conspiracy theory. How could they not? Yet the young man mentioned above has suggested we go and see a lecture by John Hartnett, an Adelaide University Associate Professor of Physics who’s also a young earth creationist. How could this be? Well I know something of cognitive dissonance and confirmation bias, but still I can barely imagine what he would say to justify his worldview, and I’m not really interested in trying to rebut his specific arguments, if he has them. These people tend to have martyr complexes about their positions, and I suspect they’d be happy to spend hours trying to bamboozle you. The main thing is to be clear about your own understanding of the evidence.
However, I also have an interest in the psychology of belief. Take the case of Hartnett, which I can only speculate about, but this is an obviously intelligent person who has apparently written scientific papers on dark matter and other aspects of cosmology and astrophysics. He knows, surely, how vast the universe is, that the Andromeda Galaxy, our nearest neighbour, is a barely-conceivable 2.5 million light years away, and there are billions of them beyond that, and yet he manages to square this with a six-day creation 6,000 years ago because it was written down by someone and collected much later with a whole mess of other writings by other people, compiled into a book and pronounced ‘holy’. Surely such thinking is more of a mystery than the gods themselves?
I can only speculate again, but Hartnett’s middle name is Gideon, a name inevitably associated with bible-bashing. Can it be that a person gets locked in, from earliest childhood, to a religious schema that they would never think to escape from, no matter how intelligent they are? Can cultural-familial influences have such a vice-like grip? Apparently so, but it’s unusual for someone to be regularly crossing the boundary between a rigid and dogmatic religious belief system and a highly speculative, often free-wheeling but rational and profoundly naturalist enterprise in the way that Hartnett must do. Ain’t people fascinating?
I’ve just read an article about rapid speciation among cichlid fishes in the African lakes. The authors note that this speciation, involving some 500 new species in Lake Victoria, has taken place over less than 15,000 years, unlike the famous speciation among ‘Darwin’s’ finches in the Galapagos (14 species, several million years). It’s called adaptive radiation, where ‘one lineage spawns numerous species that evolve specialisations to an array of ecological niches’, to quote Axel Meyer, writing in the April 2015 edition of Scientific American.
Yet this rapid speciation is still too much for young earth creationists, who believe the earth is less than 10,000 years old. What they make of stromatolites is anyone’s guess. Note that the term ‘earth’ is central, and presumably the universe or multiverse is of little concern to them, existing perhaps only as a fireworks show for our delectation.
As an Australian, this is all good for a laugh – though some Australians, such as John Hartnett, are full-on believers of a six-day creation a few thousand years ago – but apparently in the USA a substantial proportion of their very large population actually believes this (though to be honest, I can’t bring myself to believe the survey figures).
So, I wonder how I would deal with these young-turk young earth creationists who come to our atheist meet-ups spoiling for an argument. My hope is that I would have the wherewithal to ask these questions.
Is it your hope to convert the whole world to your view?
If you were successful, wouldn’t science classes be a lot shorter?
What would you do with those who insisted on being heretical? Preaching that the universe has existed for 13 billion years? Would you have them liquidated, or just permanently incarcerated? How about public recantations?
How come your god allowed us to be led astray by the evidence into getting it so wrong?
What would science be like if young earth creationists controlled all the levers of power? What would scientists do?
Of course I’m yet to hear what young earth creationists, many of whom are apparently highly intelligent, have to say about star formation, black holes and the big bang. They may well have the talent to bamboozle me with ingenious arguments. In the end, though, the best argument is to just keep doing the science, following the evidence. As long as we’re still allowed to.
Meanwhile, I haven’t yet answered the question – why is evolution (or more specifically, natural selection of random variation) true? But before I answer that, I believe that creationists do accept evolution of a particular kind, and distinguish between ‘micro-evolution’ and ‘micro-evolution’. I’ll pay some attention to that – but perhaps not too much – in my next post.
reveries of a solitary wa*ker: wa*k 2
bulldog Tommy about to land a bookish blow
The Darwin book continues to be a rollicking good read, I’m into the post Origin period, where shit hits the fans and Darwin’s fans, led by that young Turkish bulldog Tommy Huxley, shovel shit on the opposition, captained by soapy Sam Wilberforce and the brains of high Anglicanism, Dicky Owen – the most gifted naturalist of his age, to be fair. What’s fascinating is that the Origin precipitated the last great politico-religious struggle in England, a very drawn-out affair which crossed the Atlantic and continues in the US to this day, but in England it has been a slow-acting poison to conservative Anglicanism. Liberal Anglicanism, essentially a bridge to atheism, has swallowed natural selection with a sort of diffident, dumb grace, flexible as to their god’s ever-changing plan. As a semi-student of history though, I can well understand Darwin’s own diffidence about publicizing his theory. It was bad enough for the time, had it been a century earlier (impossible of course given the eighteenth century state of knowledge) he would absolutely have been martyred for it. As it was, during the couple of decades between formulating his theory and going public, the public, especially the disaffected Chartist ‘rabble’, had become increasingly keen for a weapon to strike down the High Clergy and the swanningly civilised aristos, and apes for ancestors, monkeys for uncles, even gorillas for girlfriends, fitted the bill perfectly. Darwin, of course, presented his case as dispassionately as humanly possible, with nary a mention of human descent, and afterwards kept his head down in Downe, obsessing over pigeons and orchids and sexual selection (actually chipping away very effectively at the god-did-it argument), while Tommy Huxley, Joe Hooker and co fought the good Darwinian battle in the big smoke with consummate derring-do (don’t believe a word of this by the way, as if you would). Darwin was anything but a fighter – he had vomiting fits at the very thought of confrontation – but in his oddly reclusive way he was always the leader, because unlike many of his supporters, even the closest ones, he knew he was right. His aim, his obsession, with all his apparently arcane researches, was to keep adding to the mountain of evidence.
There are many intriguing things about Darwin. He was vain but genuinely humble, highly-strung and emotional but profoundly analytical, a hypochondriac and yet a real invalid for stretches of his life, and of course a revolutionary who hated revolutionaries. As a young, footloose, disgustingly well-heeled intellectual, he could think of nothing better than to make a pleasant living as a naturalist-clergyman, like many a gentleman among his family’s connections. By his career’s end, the naturalist-clergyman was becoming a relic, probably more due to his own productions than to any other cause.
The founding father of eugenics, atheism, Nazism, bestiality and please don’t get me started
And this leads to a consideration of his most profound impact, outside the confines of science, what makes him the most controversial and contested, and in some circles reviled, figure of the past two hundred years, and that is his, and his theory’s, complete denial of human specialness. A specialness which is at the heart of the Abrahamic religions, without which not.
This recognition of human relatedness to other species, the bringing of humans back to the pack, wasn’t an anti-Christian urge by any means, it was more a result of his obsessive interest in solving the problems of adaptation and basic survival of creatures such as barnacles, earthworms and pigeons. This obsession gave him great respect for the sometimes barely fathomable complexity and ingenuity of even the most ‘basic’ life-forms. He saw human complexity as a continuation of that adaptive process, but biologists and many other scientists were, at that time, unable to shake off notions of human exceptionality. Owen, Wallace, Luis Agassiz, Asa Gray, Charles Lyell, St George Mivart and others of Darwin’s time, all had qualms about, or simply rejected outright, the implications for humanity of Darwinian natural selection, and these represented the scientific mainstream, essentially. Darwin himself was able to weather the storm through the support of strong allies such as Hooker and Huxley, his own ability to avoid and deflect controversy, his inaccessibility at Downe, his long-suffering but profoundly loyal wife, and his habit of retreating into the messy fine detail of his studies. He also, through voluminous correspondence – he would’ve loved the world of email and Facebook – built up a huge network of scientific boffins, breeders and farmers, with whom he was unfailingly polite and charming while exploiting their specialist knowledge. So he was able to adapt very well to the challenges thrown at him.
eeek
I’m writing here as if delivering a lecture, and I do wish I could reach more people. I don’t have too many contacts with a penchant for science, or for history, but then I don’t have many contacts. But enough complaining (mea culpa after all), I note that the vaccination controversy drags on, with too many people standing on their ‘right’ to not vaccinate their children, which shows up the problems with the rights concept, which I’ve always considered artificial but a useful fiction which has helped to build a more humane global society, and speaking of globalism the battle to save the lives of Australians under the death penalty is almost over, but we should continue the battle to the end because it’s a bad law and national sovereignty be damned, and that should be the same for any national under any national or state law. Which makes me wonder, I’m not a lawyer, but what would happen if an Australian citizen was charged with a capital offence and sentenced to death in the notorious US state of Texas? Maybe they only kill US citizens, that’d keep them out of international trouble, but what we need to keep working on is an international code of ethics and an international law and I do think we’re creeping towards it slowly slowly.
capital punishment – green doesn’t do it, red does, and yellow’s moving away
reveries of a solitary wa*ker: wa*k 1
(Being a thousand words or so of mental drivel)
I’d prefer not to be coy about the title but I’ve a job to protect.
the delightful enthusiasm of children
Began watching documentary series chronicles of the third reich, yet another rake-over of that terrible but ghoulishly fascinating period, and it kicked off with noted historian Ian Kershaw saying that the regime was unique in that it aimed to overthrow the entire Judeo-Christian system of ethics that sustained western Europe for centuries. Bullshit I say. No such thing. What nazism was overthrowing, or delaying or subverting, was the progress of western Europe, for example the Renaissance and the Enlightenment, movements towards democracy, individual liberty, internationalism, none of which owed anything to the Judeo-Christian belief system. This lazy thinking and remarking continually goes unchallenged. At the height of Judeo-Christian control we had monarchical dictatorships, divine right, religious authoritarianism, extreme corruption, torture, rigid hierarchies, feudal slavery, etc, a world of inhumanity and brutality. Not saying that Christianity caused this, life wouldn’t have been any better in China or Japan, doubtless. Depended on chance and ‘birthright’ as to how well you fared.
Reading the big bio of Darwin by Desmond and Moore, thinking how so much that was radical or extreme becomes mainstream within a few generations, such as materialism, atheism, democratic principles, equality for women, humans as apes. Chartism’s aims – extension of suffrage, taxation reform, the repeal of laws too unjust to be enacted nowadays, all horrific to the upper classes, who armed themselves with crowbars to protect their homes and privileges. And among them, quite a few favouring transmutation (though not of the Darwinian kind – more a sort of Lamarckian progressive development towards the human pinnacle) and atheistic science. Makes you think of today’s accelerating trends, e.g gay marriage. All these ideas were opposed because they would bring down civilisation as we know it. Rock n roll was another one.
Also thinking how science threatened and continues to threaten religion. Moslem student asked me last week, do you think humans come from apes? Could see what his hopes were, was happy to crush them and move on. No doubt he’ll return to Saudi, ask the question again and be reassured as to his human specialness. But maybe not. But in Darwin’s day, so many associates, Sedgwick, Henslow, Lyell, Owen, Whewell, even Herschel, even bloody Wallace, couldn’t countenance our ‘demotion’ to a primate, on grounds some of them didn’t even recognise as religious. How can it possibly be argued that religion and science are compatible? Only if we have a very different religion, and perhaps a very different science – panpsychism, spooky action at a distance, positively conscious positrons.
A love-hate thing with Darwin, all his stuffy aristocratic connectedness, his family’s money, but then his boldness of ideas, but then his timidity born of an unwillingness to offend, a need to be admired, feted, but two kinds of glory, the one for a grand idea that might just outlast the opprobrium of his elite class in mid-nineteenth century England, the other for being a model member of that class, civilized, restrained, highly intelligent, pushing gently outwards the boundaries of knowledge. The tension between immediate, hail-fellow-well-met acceptance and something more, his dangerous idea, something barely digestible but profoundly transformative.
Keep reading about the hard problem of consciousness, without greatly focusing. Don’t really believe in it. We’re surely just at the beginning of getting to grips with this stuff – but how much time do we have? Dennett talks of the mind as cultural construct, Cartesian theatre as he calls it, and you don’t need to have ever heard of Descartes to wonder at how memories, rehearsals, fantasies can be played out inside the head, inaccessible to everyone but yourself, but without the boundaries of the skull, or of a theatre, no straightforward boundaries of space or time, yet composed of reality-bits, physical and emotional. One of my first serious wonderings, I seem to remember (not trustworthy) was about this boundary-less but secret place-thing called the mind. Not sure about a cultural construct, seemed very real and self-evident to me, and a wonderful safe haven where you can think and do things for which you’ll never get arrested, never have to apologise, a theatre of blood, sex and brilliance…
But I don’t think I thought then, and I don’t think now, that this was anything other than a product of the brain because to me the brain was like every other organ, the heart, the liver, the kidneys, the lungs, they were all mysterious, I didn’t know how any of them worked, and though I knew that I could learn a lot more about them, and would over the course of my life, I suspected that nobody knew everything about how any of them functioned, and the brain was just more complex and so would contain more mysteries than any of the others perhaps put together, but it had to come from the brain because, well everybody said thoughts were produced by the brain and these were just thoughts after all and where else could they come from – there was no alternative. And it seems we’re slowly nutting it out, but humans are understandably impatient to find answers, solutions. We like to give prizes for them.
Also reading Natalie Angier’s Woman, a revised version of a book brought out in the nineties. It’s a popular biology book from a good feminist perspective, and I’m learning much about breast milk and infant formula, about the breast itself, about menstruation, about the controversies around hysterectomies and so on, but her style often irritates, drawing attention to too much clever-clever writing rather than the subject at hand. It’s a tricky area, you want your writing lively and engaging, not like reading an encyclopedia, but especially with science writing you want it all to be comprehensible and transparent – like an encyclopedia. Angier sometimes uses metaphors and puns and (for me) arcane pop references which have me scratching my head and losing the plot, but to be fair it’s worth persevering for the content. But it shouldn’t be about persevering.
disassembling Kevin Vandergriff’s gish gallop, part 3
Argument 7: God is the best explanation of the connection between the flourishing of the kinds of moral agents there are, and the necessary moral truths that apply to them.
Here we move more and more into the field of the preposterous, IMHO. He quotes a Christian philosopher, Gregory Ganssle, as saying:
Not only do we have beings to which necessary moral truths apply, but we have beings that are made up in such a way that doing what is right turns out to be good for them, it contributes to their flourishing rather than their languishing. Maybe only one in ten universes that are moral, in that they have the right sorts of beings that are such that moral goodness, and the flourishing of those beings involved, converge.
The last sentence is virtually meaningless, but the emphasis here on necessary moral truths is bizarre. I’m not sure what they are, but I’m certain that I haven’t the slightest interest in the concept. Vandergriff spoke earlier of the prohibition against murder as being a necessary moral truth, but many Christians are in favour of capital punishment, which is murder by the state. The murder of Bin Laden a couple of years ago raised very little moral outrage, nor does the murder of hostage-takers and other terrorists today. So these are apparently moral prohibitions that are on some occasions more ‘necessary’ than others.
I find the pretence of surprise that acting on ‘necessary moral truths’ seems coincidentally to promote human flourishing to be ridiculous and thoroughly disingenuous. The fact is that we’ve promoted human flourishing through social evolution. One of the most comprehensive explanations of how this has been achieved is presented by Steven Pinker in The better angels of our nature, a work of empiricism, not philosophy. Pinker has no more interest in ‘necessary moral truths’ than I do, he is concerned to explain how some human populations, and an increasing proportion of them, have been able to learn from the destructive errors of the past and to build better legal, economic, political, social, health and education systems, to better balance co-operation and competition, and individual and social goods. His analysis owes nothing to ‘necessity’, everything to the lessons learned through bitter and often traumatic experience. There are no perfect systems, but polities can be improved grindingly through continued analysis and experiment based on hard-won knowledge. Vandergriff and Ganssle put the cart before the horse. We flourish because the systems we put in place are designed for our flourishing. Yes, horror of horrors, our morality is all about enlightened self-interest, not ‘necessary goodness’. The horrors of the Great War drove us to attempt, for the first time in history, an organisation of international co-operation. Its dissolution was a setback rather than a complete failure. The later United Nations, with all its failings, has gradually grown in strength and will continue to be a force for peace, together with other international and intergovernmental organisations. The success of Medicins sans frontieres has spawned similar organisations ‘without borders’, and the trend is likely to continue. People get enormous satisfaction from helping others. Selfish satisfaction? Yes, but that vastly oversimplifies the matter. It is above all the satisfaction of being connected, which is so important for perhaps the most social species on the planet. And our increasing knowledge of our connections with other species is expanding our circle of sympathy, as philosopher Peter Singer has eloquently pointed out.
But as you might be able to detect, my sympathy with these arguments is starting to run out, and it gets worse.
Argument 8: God is the best explanation of why there are self-aware beings.
It should be pointed out that supernatural beings of any kind (let alone the mass-murdering war-god of the Old Testament) are always massively problematic ‘explanations’ because they have no empirical foundation. These are abstract objects, in spite of their variously imagined ‘histories’ in innumerable sacred texts. The development of self-awareness in many species on our planet is a contingent empirical fact.
Argument 8 and all the other ‘best explanation’ arguments given by Vandergriff, William Lane Craig and other theists are usually accompanied by claims that ‘this situation/these events are extremely improbable under naturalism but entirely consistent/to be expected under theism’. That’s to say, they’re all ‘cart before the horse’ arguments. You define your supernatural agent as the repository of necessary truths, the generator of all value, the seat of ‘infinite consciousness’ (as Vandergriff quotes J P Moreland, another theist philosopher and theologian, as claiming), and the source of all meaning and ‘worthwhileness’ (argument 10), and then you say ‘hey look, we are value-seeking, meaning-requiring, self-aware, necessary-truth-understanding beings, so surely the whole kit-and caboodle was made by a god who made us as close to him as anything else, because he cares so much for us. Otherwise, all our amazing attributes are meaningless.’ I should point out that the amazing attributes of non-human species are constantly downplayed by theists, as they are in Vandergriff’s spiel, because they don’t contribute anything to this unique god-human relationship. They were downplayed throughout the Christian era too, of course, before it was challenged by the theory of natural selection. Stephen Jay Gould has cited many cases in his essays: for example the early 19th century German embryologist Lorenz Oken wrote that
The animal kingdom is only a dismemberment of the highest animal, that is, of Man
and in an 1835 work, naturalist William Swainson reflected thus:
When we discover evident indications of a definite plan, upon which all these modifications have been regulated by a few simple and universal laws, our wonder is as much excited at the inconceivable wisdom and goodness of the SUPREME by whom these myriads of beings have been created and are now preserved, as at the mental blindness and perverted understanding of those philosophers, falsely so called, who would persuade us, that even Man, the last and best of created things, is too insignificant for the special care of Omnipotence.
We readily forgive these dated claims, partly because they don’t directly challenge us any more, bit it seems clear that many theists have learned nothing and forgotten nothing over the centuries. There are many obvious problems with this way of thinking, but the one I find most indigestible is that in order to avoid the horrors of contingency, which, certainly in the case of William Lane Craig, is the greatest and most unacceptable horror of all, theists are still forced to conclude that everything – the possibly-infinite multiverse, the big bang, quasars, black holes, dark matter and dark energy, gravity, quantum mechanics, the laws of nature, the elements and their proportions etc etc – was created by their god for us. We, containing so many of the god’s qualities, albeit in infinitesimal proportions, are the fulfilment of his purpose. We are what he created it all for. Not a geocentric universe perhaps, but an anthropocentric one for sure, with a complexity that the god gradually reveals to us as our privilege to work out.
So theism here presents us with a choice, or so it believes: total meaninglessness, or the humbling knowledge that we are central to a god’s plan, the pinnacle of his creation, created in his image, fumbling caretakers of his multiverse. As fantasies go, it’s a whopper. From an empiricist perspective however, it’s a non-starter, except in psychological terms. It has helped our forebears to get through many dark nights of history.
I’ll dispense quickly with Vandergriff’s last two arguments. Argument 10, God is the best explanation for the worthwhileness of life, is just more of the same and requires no further analysis. Argument 9, probably the most preposterous of all the arguments, is that ‘God is the best explanation of the historical facts about Jesus of Nazareth’. There are no historically established facts about Jesus of Nazareth, even of his birth, his preaching, his trial and his death, let alone of his putative miracles and resurrection. Scholars may argue to and fro about these matters, but their arguments are entirely textual and have no serious empirical value.
Okay, I’m done with this. Never again, I hope.