As a biologist, I don't think this really follows. From my perspective of studying life, 3 billion DNA pairs can definitely evolve randomly - it's not even really that hard. Eukaryotic life just happened to get that because the fitness deficit from the retrotransposons weren't too bad. On the contrary, I can't actually see how bioelectric could drive evolution - only the creation of more complex structures
Like, of COURSE the Venter cell looks too complicated to originate from raw chemicals! The lineage it evolved from was far more complex, and Mycoplasma underwent minimization. Minimal life also does not equal simple life, or life that was most probable to arise from chemicals. Just a stupid premise, really.
In reality, of course, religious explanation has no such presumptive default or incumbent status. Religious explanations are just one of many potential explanations for how the world works and compete on equal terms with any other. And when the religious explanation really just boils down to some variant of "god did it", it becomes very obvious how inadequate that is compared to even the worst scientific attempts.
Related: religious apologists constantly try to pretend that criticisms or problems identified with scientific explanations somehow count as points in favor of their religious alternative. This is also a false idea. It is not a debate, where pointing out flaws in your opponent's argument helps yours "win". It is a search for truth, and finding fault with another theory does nothing at all to enhance your own.
It does not.
Here are some example chapter titles:
Homochitality of building blocks
Boipolymer Reproduction
Means of Gene Regulation
Selectively Permeable Membranes
The whole book is just an examination of such scientific issues.
Religion doesn’t come in to it anywhere.
"One purpose of this book is to call out and clarify the leap of faith that atheism implies." - p185
You're now just straight up lying and I'm done with you.
If you'd please review https://news.ycombinator.com/newsguidelines.html and stick to the rules when posting here, we'd appreciate it.
https://news.ycombinator.com/newsguidelines.html
Edit: please see https://news.ycombinator.com/item?id=40648381 also, because you broke the site guidelines badly downthread.
In fact I want people to research the question of the origin of life as rigorously and exhaustively as possible because it is just going to make it that much more obvious that life was designed by God.
I have absolutely no fear that this "gap" is going to do anything but widen.
> Two-headed worms made this way reveal a permanent revision of the target morphology: subsequent rounds of regeneration in plain water, long after the reagent is gone from the tissue, continue to make two-headed worms.
the objection to the process described here is reasonable. thankfully this isn't how it works.
Care to elaborate what lowers this probability down to "computable within adolescent age" levels?
Something like "the computational complexity of a beached fish to invent and grow a leg is O(n^2 log n) hours where n is the number of neural spikes in frontal cortex" or similar.
Also, there's horizontal gene transfer to account for. It further complicates the picture.
https://www.discoverwildlife.com/animal-facts/fish/can-fish-...
Genes get duplicated by accident, then accumulate mutations which are usually neutral or worse. Occasionally they help you achieve something slightly more useful than before. Lobed fins that helped you heave yourself back into water when you get beached would have helped. bigger lobed fins would help you get back when stranded further up the beach, or get from pool to pool. It's unlikely that an entire set of limbs, other necessary body upgrades to support them and neural circuits would just hang around waiting for all the right mutations to collect like hole punches on a restaurant loyalty card before some critter slapped their thighs and stood up and walked. Evolution does not plan ahead.
this is an argument from personal incredulity. just because you are too dumb to understand how something works doesn't mean that your fantasy/sci-fi version is accurate. brains changing genes belongs in a discussion of Neal Asher's polity, not in a biology discussion.
thankfully, nobody is claiming that happens. i can explain more, but there's the issue of my fees. £200,000 seems reasonable, given how dumb you are.
The current best hypothesis is that RNA randomly developed and evolved. Some if it happened to be self-copying. If there are self-copying things, there will be lots of self-copying things - that's common sense. And a genetic algorithm fitness function. In an ocean with RNA, sometimes it will happen to bump into other bits of RNA and swap over. Sometimes they randomly get better at copying. Zillions of molecules and hundreds of millions of years is a long time for small chances to happen. We want genetic algorithms to run in seconds on a PC. Ones that run for millions of years in the Earth's whole ocean don't have to be nearly as good.
The Miller-Urey experiment demonstrated that chemicals we know as building blocks of life can come into existence by themselves in early Earth conditions. What we don't know yet is exactly how they got from there to cells, since we don't have a time machine to go and look. Scientists keep finding plausible stepping stones, though.
my fees are not conditional on you liking the lessons. they are to be paid upfront. i accept the higher offer though.
Can you prove it? Show me some sort of an environment where a water-based complex organism is able to survive and thrive in dry environment prompting it to grow a new movement organ useless in the water but needed on surface and give me some less-than-exponential algorithmic complexity bound for it. If you can't do it, you don't offer valuable lessons.
edit: sorry dang, I fell for it again, didn't I?
edit 2: actually treprinum, I have a sensible answer here, although you're not going to like it. if you were smart enough to understand what you are asking, you really wouldn't have picked body plan as your "gotcha". you would have picked something truly wonderful like the genetic code, or the ribosome, or mechanisms of gene regulation, or embryology, or eukaryotic cells.
the evolution of new body plans is very well understood. i won't explain it to you though, until and unless I get paid. I believe we agreed £50,000/h for an hour minimum lesson which is three hours of prep - so £200,000 total for the first paid lesson? this one here is free.
https://education.nationalgeographic.org/resource/west-afric...
If neural spikes had anything to do with it, if any of this worked like that, bacteria wouldn't develop resistance to antibiotics (they can), and I would be able to shapeshift (I can't).
So that question is like asking for a route finding algorithm that's O(n) where n is the number of letters in the destination.
If you seek understanding, you must decide upon a specific better question of your choice; if you leave it up to us to devise the question, we can do that, but it's overwhelming unlikely that our free choice will connect with whatever it is that led you to ask the question in the first place.
For example, I could ask you to consider a model of a fish where each bone length is controlled by some gene, and then evolution converting fins to legs is some function of the magnitude of reproduction selection pressure on those changes over multiple individuals and generations… and nothing at all to do with one individual's brain.
Or were you thinking of a specific fish species which develops legs when it reaches adulthood?
That's not even an example of a paradigm shift. Continuous transformation trivially gets us between superficial differences like mere body shape, there are many examples of us applying selection pressure to other species to make that category of thing happen, including our crops, livestock, and pets — no more than 10k years separated Chihuahuas and Corgis from Newfoundlands and Afghan Hounds. Likewise even more extreme changes between crops and their wild relatives, the wild versions are almost unrecognisable except to experts.
> You are mixing the two together and complaining the second one is non-sense, but is it?
What I'm calling nonsensical is your description. You're calling for the time complexity for a brain to invent changes that aren't caused directly by brains.
> Somehow fish had to learn to walk ("evolution from one organism to another") in a limited time including complex mechanics that our computers can't solve exactly
1) Exact solutions aren't necessary; 2) computers have solved walking; 3) the boundary between walking and floundering is an arbitrary one. And #4 after the next quote…
> I am waiting for any computational biologist to give us some mechanism behind it that is realistic,
4) One of the ways computers solve problems like this is simulated evolution.
If you don't consider the working demonstrations to be realistic, that's a "you" problem, not something the rest of us care to waste time on.
> So far nothing and people keep mentioning local adaptations only.
Do you also insist nobody has ever climbed Mount Everest on the grounds that nobody has legs long enough to do it in one step?
Or that motion pictures are impossible because each frame is stationary?
Your interpretation of bioelectric effects as summarized in this article seems to have missed something. The bioelectric network is itself an expression of the genes involved in development. It’s not a separate magical force.
Yes, you may need genes to express the proteins of ion channels and gap junctions, but there is no anatomy coded by genes, no genes code for how many limbs will a biosystem have (as reiterated by Levin). And it is this level of resolution that actually mattered for years before the launch of molecular biology and medicine.
>>It’s not a separate magical force.
Indeed, it sort of (suppose - by up to 70%) is. If the fine structure constant, which defines the strength of the interaction between a charge and an electric field, were 4% less or more than its current value, the current world and biosphere wouldn't exist. So far physics can't explain why the fine structure constant has this exact value (~1/137, which is also unique that it is a dimenionless constant). (I'm not inferring anything, just presenting raw data).
What's this supposed to mean? We are already able to develop bugs with missing or additional limbs by modifying their genes.
You do realize this is untrue?
But I remember he was mentioning some study in left/right asymmetry in DevBio, where they've shown that it's cell potentials/bioelectric signalling and not genes that determine the left/right asymmetry in embryos.
No, they've shown that electric signaling is how the genes determine the left/right asymmetry in embryos.
How do you think it is that the same thing happens so consistently every time a new organism develops? Where do you think the electric gradients come from?
This suggests you have not tried writing a simulated evolution based optimiser.
They're quite easy to write, the hard part is what you mean by a "fitness function" (which doesn't matter for nature, it just is whatever it is).
Such algorithms are also more than fast enough — remember that for the first 3 billion years we only had single-celled life, and that can reproduce in 20 minutes, so we had potentially 79 trillion generations (edit because "78.84 trillion" would be overselling the precision) before the first multicellular life. You get good results faster than that.
The number of base pairs is also just a misleading statistic. For example: each of XXX, XXY, XYY, and Downs are found in around 0.1 of human births, each of which gets an extra copy of a chromosome. These specific changes may not be too good for us, but this kind of sudden massive increase is also found in some plants without negative repercussions.
> However, bioelectric might be a much much more straightforward and fast way of driving evolution instead of randomly mutating DNA.
I have no reason to expect bioelectric processes described in this article to be able to direct useful effects on the genome, for the same reasons I think it unlikely your own brain could by sheer willpower turn you into a werewolf.
Wrong layer of abstraction.
A couple notes:
Downs is unlike the other defects you mentioned in that it severely impairs the patient while the various extra-sex-chromosome disorders vary from sterility through minor impairment to what basically amounts to behavioral differences.
Downs is unusual, though, in that most extra chromosomes make the fetus nonviable. As far as trisomy disorders go in general, Downs is unusually benign.
Plants are better known for increasing their -ploidy (number of sets of chromosomes) than the count of an individual chromosome. A triploid human, with three copies of every chromosome, would be hopelessly nonviable. Plants are different. Really different.
That said, my experiments in silico say that what matters most is the pressure from the utility function, more so than the rate of mutation.
So if some organism is in an environment where only a few mutations help, then evolution progresses slowly; and when most possible changes are improvements, then evolution progresses faster.
Both environments can happen even without any dynamic change to the rate of mutations themselves.
- Life reproduces; between imperfections in reproduction and environmental mutagenic factors, there is a certain amount of random mutations;
- The churn happens. Organisms compete for resources; winners reproduce, losers starve. Environment throws curveballs - spills, seasons, volcanos, radiation, oxygen, and a million different things. A lot of organisms are killed, some survive and reproduce. Now, mutations can make organisms better or worse at surviving the challenges. This is the asymmetry you're looking for, the driver of evolution. Helpful mutations propagate, unhelpful mutations die. Where "helpful" means, of course, "helpful locally, at a given moment".
Rinse and repeat. The randomness isn't the driver - it's just jitter preventing evolution from getting stuck in a local minimum. The life cycle of birth and death is what drives evolution, specifically because it depends on both how the organism is built, and on the environment.
There's a knack to optimizing the mutation rate. If you mutate too much, 99.9999% of offspring can't develop and in the end there's too little reproduction. If you don't mutate enough, you don't evolve. Evolution has already optimized this hyperparameter.
This a-ha moment for me with respect to this is that some biological processes are of the type [random process -> selection -> stable result]. This means that the genetics actually _don't_ store the information for what is ultimately produced, only the information necessary to trigger a random exploratory process and to stabilize that process when it reaches a suitable target. This is one reason why animals can flexibly adapt their development to different conditions as described in the above article.