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Wow, what an interesting article, not all about feathers. There’s so many genetic mysteries about skin appendages still to be uncovered e.g. in humans, how do nails and hairs manage to grow only in one direction (and perhaps even more remarkable, always so).

I was drawn to this side point though: the microraptor has four wings. Not like a dragon, of course, which has to be an insect, but an ordinary quadruped that used all four limbs to fly (compare that to mammals with a membrane between the forelimbs and hind limbs on each side). I imagine it must have looked like an F-35 when flying.

Seems like it turned out to be optimal to stick to two, not just for terrestrial mobility, but due to the (bidirectional!) optimization of the wishbone and the chest musculature. It’s probably hard to get enough power into the dual-mode hind limbs. Sadly the Wikipedia article on the microraptor doesn’t explore this.

> Seems like it turned out to be optimal to stick to two

You can't conclude that. Evolution is noisy and random.

Besides, birds are not unambiguously the most optimized flying vertebrates around.

> You can't conclude that. Evolution is noisy and random.

You're correct that you can't conclude that evolution is perfection/optimized, but it's also not correct to say it is random. The genetic variation is random, but natural selection is very much not random[1][2].

[1]: https://evolution.berkeley.edu/misconceptions-about-natural-...

[2]: See Number 7. https://www.pbs.org/wgbh/evolution/library/faq/cat01.html

Random doesn’t mean all outcomes are equally likely, a coin rarely ends up on its edge.

Thus evolution is often random between local optima. People’s organs don’t represent perfect left/right symmetry but there’s no particular benefit for which of the two options were chosen overall. Ie swap just which lung is smaller and you get lots of problems, but swap everything and it all works.

Local optima are also the reason you get things like the recurrent laryngeal nerve, which runs from the brain to the larynx going under the heart. bad enough in a human, a huge deviation in a Giraffe or a Brontosaurus.

Regardless, it doesn't have agency and isn't clever. Personally I belive in a Designer, but since middle school I've been bewildered by the way evolution is almost always presented, outside of rigorous scientific literature, as if there is agency, intelligence and intent behind it.

I don't have a problem with that, but materialists don't have that luxury and use language in bad faith when do it.

You might enjoy Dennett’s “The Intentional Stance” for some enlightening exploration of this metaphor, e.g. “The thermostat tries to keep the temperature between 67 and 69” not only makes sense but is a useful way to think of it even when we don’t believe the thermostat has agency.

The thermostat was ultimately designed by a mind that has objectives. That is why it tries to control the temperature.

What about the ocean? The ocean also "tries" to keep the temperature steady.

That one doesn’t quite work for me. A thermostat has a purpose: keep a temperature. An ocean doesn’t really have a purpose.

As humans we do things for teleological reasons. Meaning we can say we did X in order to accomplish Y.

Ascribing teleological explanations to evolution is technically wrong, since it doesn’t look ahead.

However, it does something very similar. Our brains process competing options, from plausible to nonsensical, before selecting an action, partly in sequence (ideation), but also in parallel (competition processing).

Evolution tries many options in parallel and sequence too. Just by actually doing them and then selecting which of those choices to keep repeating (better survival), and those to forget (extinction of genes, clusters of genes, or whole species).

So over longer time periods, it acts very teleologically. A kind of reverse teleologic by hindsight.

The same is true for the “brilliance” of this teleology. Evolution tries so many things, that it can solve very difficult problems in very novel ways.

Is that “intelligence”? Our casual usage of intelligence isn’t defined precisely enough to say one way or another.

One person would say evolution is blind, and in the short run it is. But another person might point out that evolution is anything but blind. It is an epic version of Edison’s lab, where millions or billions of false solutions are continually tried and ruled out, to find each new fitness enhancement.

It relentlessly experiments and follows the “data”.

On longer timescales, evolution is effectively teleological, highly creative and very intelligent.

And all three aspects compound over time, just like human learning and research, because evolution doesn’t just find new features, but new abstractions and modularity. Such as flexible reusable gene systems for encoding body parts, epigenetic reuse of features in different kinds of cells for different purposes or triggered and “run” by different conditions, nervous systems, etc.

Thus evolution “learned” to speed itself up over time, letting it more rapidly optimize larger more complex solutions. I.e. orders of magnitude faster creation of new novel animals, than it originally took to optimize the first cellular life, colonies of cells, etc.

Watching evolutions first billion years would not have suggested that the plethora of different intelligent animals, from octopus, parrot to human, would have been remotely possible in the time it took. Evolution’s compounding meta learning created brains, our “true” teleology, and its expansion into technological and economic expressions of the pursuit of survival. All meta extensions of evolution, found by evolution.

There are single proteins that need to "evolve" somehow, but they need to arrive at a very particular shape, and extremely near misses offer no feedback information and are just as good as dead.

But the combinations of amino acid sequences they would have to search through in order to find the correct shape is so large that it is greater by several orders of magnitude than the sum total number of all the organisms that have ever lived on Earth since the beginning of time (which is about 10^40, I think).

So your claim that "evolution just tries so many billions of options, man" just doesn't hold water.

There was a time, back during the 1960s, I'm told, when mathematicians in the academy would openly mock evolutionary biologists for their lack of understanding of statistics. But then political correctness took over or something.

> But the combinations of amino acid sequences they would have to search through in order to find the correct shape is so large

Evolution isn't looking for that sequence.

It is looking for any change in sequence with a positive payoff, and in the meantime constantly diversifying sequences with similar outcomes, creating more opportunities for serendipity.

Every large animal is born with mutations. So we are also quite robust to spreading the search, running multiple experiments at a time, taking small risks with genes not quite as good, which will get weeded out quickly when combined with other weaker genes, but in the meantime cast a wider net for meshing with another gene that complements it.

So yes, in any given species with a nontrivial population, millions or billions of genetic variations are being explored at any point in time. We are nothing like carbon copies of each other, differing by just a couple checkmarks.

This is a radical speed up. Just as sexual recombinatory reproduction is. Evolution today operates with vastly more efficient genetic environment, structures and systems than what early life did.

Tractable statistics do no justice to how biology works and all the paths it searches. I am not knocking formal statistics at all, just noting that past one or two step events, the layered statistics of chemistry, genes, gene clusters, epigenetics, populatoin dynamics of complex creatures in their complex environments, etc. are not going to be tractably modelled.

Measurable sometimes for sure, but not symbolically characterizable or calculatable.

> It is looking for any change in sequence with a positive payoff

The entire reason I used the example of the combination lock was so that hopefully you would understand situations in which "any change in sequence with a positive payoff" is a nonsense concept. You either get the correct combination or don't get any positive payoff whatsoever.

When you are trying "millions or billions" of genetic variations are being explored at any point in time, as you point out, you are off by so many orders of magnitude in terms of the search space that you need to explore that the problem is intractable.

You may as well tell me that you can guess a random password that I come up with because you have a way to test millions or billions of combinations at a time. That's great, but I can come up with a random password that it would take you from now until the end of the universe to guess even if you guess quadrillions of possibilities at a time because I can create a password that would require you to test 10^84 possibilities.

Do you consider that not all possible evolutionary combinations are equally likely?

IIRC, evolution is an optimizer but not intelligent. Some of our expectations of intelligence are actually more lax than people think and include optimizers.

Until we find out that evolutionary steps/genetics are the firings of the neurons of some planet scale brain that thinks using evolution. We do have quite a bit of junk DNA ;)

Almost makes me wanna write a scifi short on it.

That's amazing. Did you just type that out or did you spend a couple of years preparing it just in case?

That's funny. :) I just typed it out in one splat with a few quick edits. But I spend a lot of time trying to get clear and distilled perspectives of everything interesting.

It's hard to explain an animistic force of nature to another human without using words that imply agency. It feels like our language and our ways of thinking are hard-wired to see everything through that lens because we have agency. It's like a fish trying to imagine what it's like to be outside of water.

Didn't Darwin write a book that did just that?

Yes, but reciting the entire book mid-conversation isn't a realistic option.

Bruce Lee's injunction "be like water" probably means don't overcomplicate with agency and opposed consciousnesses, just evolve the lagrangian (towards victory).

(Speak not of the relevant XKCD)

So you believe in a "force" that creates life?

Pastor says that the four fundamental forces are necessary and sufficient to create life.

Dude, that's just the language. "Water wants to flow downhill". It's a model, man. Everyone learns this pretty quickly. I don't get how this position is so popular on HN/Reddit. The language is giving you tools to model the world.

"The water doesn't want anything. It's just the laws of gravity."

Intelligence comes from being able to efficiently compress highly predictive models. Any computational mechanism that is unable to do this is a low-grade intelligence. If you need the whole thing spelled out carefully for you, you're NGMI.

You can say "water flows downhill" instead.

Why not say things in the more accurate way.

[dead]

Humans anthropomorphise everything, I’m pretty sure it is how we run general intelligence software on small pack hunting tribal creature hardware: we model evolution as a clever sentient trickster and speculate about how does things.

I've observed this as well. People who believe in evolution can't seem to stop themselves from using "intelligent design" language to anthropomorphize evolution.

I agree with the sentiment. I also heard of some books that say stupid things like humans have not yet reached the maximum of human evolution.

Of course we have not reached the end of our evolution. That will exist only when we are all extinct.

As for the direction... that is something else. Maybe we will evolve into higher intelligence, but as the Dick's story "The Golden man" or "Idiocracy" show, is the intelligence really the driving force of today?

> is the intelligence really the driving force of today?

Yes, certainly. More than anything intelligence differentiates us as a species.

I don't agree. Women, in general, don't find men attractive because of intelligence. It's other factors more like, whether their life is in order, they are fit, or the classic, if they are symmetrical.

So, we are visually, materiallistically oriented. Not all, of course, but evolution works on population size, not exceptions. Exceptions only come into an overbearing effect on cataclysmic events.

It's not that kind of intelligence that matters. Don't think in terms of being good at chess, poetry, or multiplying numbers in your head. Think wheel, writing, domestication, agriculture, petrochemical engineering, nuclear weapons, computers, genetic engineering.

Our intelligence is what allows us to acquire and improve new adaptations without having to change our own genetics. We're able to change living environments and adapt to them multiple times in a single life span, and we went from basic language to walking on the Moon much faster than evolution is able to make meaningful changes through natural selection. It takes however many million years for a species to grow fur to adapt to cold climate; it took a spear for us to adapt by stealing other animals' fur, and couple hundred years to figure out how to make synthetic ones at scale. In that time, we adapted to almost every environment on the planet.

Intelligence very much is the driving force behind humanity.

EDIT: and we're also beating natural selection from the other end - modern medicine allows many people to live and reproduce, who without it would've died from genetic diseases. We're very good at denying the "fitness" criteria nature uses.

While I agree with your general slant, it's not correct to say that evolution can't act quickly. Evolution can act, and does act, slightly faster than a single generation. Populations change rapidly, and the success, failure, life and death of individuals and their guiding behaviors, change with it. The introduction of online dating, for example, has already caused evolutionary changes in our species. Only time can tell if these changes are going to last. Just because we haven't yet generally grown thumbs adapted for interacting with iPhones doesn't mean that the more subtle changes haven't happened.

While I agree in the sense that what you say improves human race survival vs whatever-else comes.

But evolutionary pressure also occurs within the species and for the human race $$$ has largely influenced demonstration of procreational traits.

Intelligence doesn't matter if you are smart but don't have any opportunities. The other social cues, fashion, appearance, physical fitness, health, being "funny". Are all a lot easier if you have $$$.

So many conversations around modern population fertility rates have a $ component in them.

Maybe being intelligent matters more than simple strength and coordination used to. But what kind of intelligence?

Maybe being a sociopath such that you can bully your way to CEO - or to a high enough level you meet some "darwinian fitness" threshold.

But in and of itself, being able to engineer the feat of walking on the moon didn't make all the nasa employees inherently more desirable to partners to procreate. Those employees maybe had attributes that matched with desirable procreation partners and maybe that feat brought $$$ too - but the engineering smarts alone isn't it.

Diminishing returns. People vastly prefer a partner who can communicate using language over those who don’t, that’s a huge preference for intelligence just not an unlimited one.

Similarly most people want some level of success be that artistic, financial, athletic, etc and success is highly correlated with above average intelligence. 101+ IQ’s might not seem that impressive but over a long time scale that’s an endless treadmill.

Consider talking to more women.

Women prefer men that suit their goals. Their opinions and experiences shape their goals. They are not a hive mind.

Women on the more narcissistic end of the personality spectrum may prefer ugly men, poor men, dumb men, low self esteem men, etc. so they can control him. Narcissistic men do the same when picking women.

This isn't even exceptional behavior. It might even be the norm depending on where you live. People who aren't as narcissistic may prefer to be single for much of their life.

Evolution doesn't care how today's politics perceives these personality traits. If they lead to reproduction they will continue. On this topic, it's not even evolution but culture and simple family traditions!

Evolution in humans, from an atheist perspective, is consistent with the idea of a designer: humans are the designer.

Sexual selection in humans is a psychological phenomenon, and it’s subject to all of our most hifalutin ideas.

You have an opinion about what “god” wants and express it through sexual selection, thus influencing our collective evolution in that direction.

Also ironically, by the time we became able to conceive of and communicate about such ideas, natural evolution has long stopped being the driving force behind how humans and human groups look and grow and evolve.

Evolution is still very much a driving force in humanity. Every time a couple struggles to get pregnant, every time birth control fails and results in an unplanned pregnancy, every time someone decides to be child-free, every time someone dies young, etc., etc., humanity evolves toward one genotype over another.

If anything, I would argue that human evolution has accelerated in the last few decades (at least in wealthy nations where people have a lot of control over their reproduction and enormous choice in who they marry, if they marry at all).

But why do they want what they want, and how much agency is there really anyway ?

Natural Selection is not the interesting part, though. Natural Selection is the boring part. Obviously a working system will be selected over one that doesn't work.

The interesting question is where the working system that Natural Selection was able to select came from in the first place.

> natural selection is very much not random

Except where punctuated by (subjective) catastrophe.

But then it is not the mechanism of evolution itself that is random.

Well, it's never random, is it? It's only random when all is equal, otherwise it's biased. That's why it works.

Consider birds. There was a good article a few days back, on why only non-toothed birds survived. Until the meteor-strike, 65M years ago, all was equal and they survived along-side. Until they were the only survivors.

The asteroid that created the Chicxulub impact came from a rather random location but had a deterministic effect given where it struck.

And here we are, with beaked birds. ^_^

https://en.wikipedia.org/wiki/Chicxulub_crater

No, but the pterosaurs might have been, because their (likely) quadrupedal launch implies they could optimize away all unnecessary muscle (read: weight) from the legs, so they inherently could optimize their body plan better.

And they also had two wings.

[0] https://en.wikipedia.org/wiki/Pterosaur

[1] https://www.youtube.com/watch?v=scAp-fncp64&t=150s

[2] https://www.youtube.com/watch?v=9TKgupAZVzE

Maybe optimized for their niche.

I remember reading something about bombers maybe during ww2. I think if fighters were chasing them, the bombers could escape because with their large wings, they could fly high and slow and turn inside them.

the analogy being - some birds might be set up for ground operations and chasing prey, others living in a different ecosystem with high altitude cruising over long distances.

Birds are more optimized than bats in some niches (like long-distance flight), but vertebrate evolution is very stuck into path dependency, and they are way far from the optimum on the things that matter for most animals like maneuverability and acceleration.

Four-winged birds dying up can easily be a complete accident, even more because two-winged birds were almost completely killed once too.

> Besides, birds are not unambiguously the most optimized flying vertebrates around.

What is a flying vertebrate that is not a bird? Bats are all I can think of.

A bat?

Yea, sorry. I was editing that in before I saw your comment.

There's also flying squirrels, though they don't have true flight. They have enhanced gliding to leap further.

Edit:

Oh, look: flying lizards and flying fish:

https://wildlifeinformer.com/flying-animals-that-are-not-bir...

The hair on your head grows indefinitely. The hair on your arms and legs grows to a certain length and then stops. You can shave it off, but it grows again, but only to that same length.

How does the hair on arms and legs 'know' how long it is?

No, both grows indefinitely, it's just that head hair takes more time to fall off

This was just asked and answered in /r/askscience

https://www.reddit.com/r/askscience/comments/1c6zztu/why_doe...

https://www.washingtonpost.com/news/speaking-of-science/wp/2...

Different anagen phase durations.

Still doesn’t answer - How does the follicle know that I cut my hair and needs to grow again to that length?

It doesn't know. Hair cycles are constant. If you didn't cut it, it would eventually fall out as it is replaced by another hair. It grows to the point where the epithelial column contracts and starts forcing it out. This is based on environment, nutrition and genetics and varies from person to person and is affected by everything from stress to blood flow.

You can observe this on many people by looking at hair miniaturization of people who have MBP or similar -- the follicle constricts in size and the resulting hair that comes out is progressively shorter in length and diameter until the follicle is so constricted that it no longer produces hair.

It doesn't. Hair grows for a certain amount of time - time, not length. Then waits for a while unchanging, then falls out.

growth (3 to 6 years) -> static (2 to 3 months) -> fall out -> rest -> start over

The maximum length of your hair is determined by how long it stays in the growing phase, in general this phase is longer in females than in males. And some people are naturally able to grow longer hair than others.

In pregnant females the static time is increased, i.e. the hair stays there without falling out. This makes their thick and full. After delivery this changes and the hair falls out in clumps, which is unpleasant, but it's the same hair that would have anyway fallen out earlier, it's not extra hair falling out.

If you cut the hair nothing changes, it still grows for as long as it was going to originally.

That myth about cutting hair (or shaving) to make it grow faster or whatever is not real.

Interesting. I've occasionally wondered why my hair (from scalp) can reach barely half way down my back, even after leaving it for decades uncut, while other people (typically women?) can grow it to the floor.

Yup, that's exactly it.

I've always wondered if the almost universal preference for women to have long hair is linked with their ability to have long hair, while for males people (not you :) typically want it short, which matches what males are able to naturally do.

i.e. which came first? The ability for hair of a certain length, so that's what people like, or if people like hair a certain way so natural selection helps out.

Perhaps men couldn't win so decided not to play.

This doesn't seem right. If I use clippers to trim hair on my body, it grows back to its 'natural' length. I don't end up with hair of various lengths. Likewise, if I shave it, I don't end up with some stubble and some regular hairs.

I've never experienced a time where I've trimmed body hair and had it remain the same length for a couple of months.

> I don't end up with hair of various lengths

Look closer, the hairs are random length. You have to wait of course for them to reach natural max length, and then you'll see a randomized mix of lengths.

If you are always clipping hair they will almost all be at one length because > 90% of them are still growing and then getting trimmed. The rest (a minority) have recently fallen out and are just getting started and will be shorter.

Does that make sense?

> This doesn't seem right. If I use clippers to trim hair on my body, it grows back to its 'natural' length. I don't end up with hair of various lengths.

Are you sure? I have fairly hairy body so when I use moisturizers it tends to stick to the hair instead of the skin, and since I'm trying to take care of my forearm tattoos, I trim my forearm hair on a regular basis, after a few weeks, if I look closely, I can see some hairs being around, say, 2cm long, whereas others are just barely growing out.

IIUC, it doesn't. Hair grows for a certain time period, falls out, and regrows. The follicle has no knowledge of the length of the hair it is producing, it is simply on a grow-stop-shed cycle with a certain period.

So hairs are actually excretions, like sweat and shit.

Exactly. It's like having a bazillion tiny 3D printer extruder nozzles embedded in your skin all on their own timers and flowrates.

What’s the opposite of a fun fact

Teeth

There are possible physical answers; it could be lack of inertia on the hair triggers growth. It could be that when you rub your arm, an action as innocent as a yawn, you are also informing the growth of hair. Could it be as simple as looking at your hair or knowledge of shaving causes a subconscious trigger? We already know that these high level shortcuts into low level processes exist (Pavlov's dog anyone?)

It's none of those. Read the sibling replies to your comment.

Does it drop off after a certain time period (= length)?

that would be my guess.

What happens when arm hair get implanted on head? Do they grow like arm hair?

A friend had a skin transplant — inside thigh to foot, IIRC? it was a long time ago — but I do recall that they told me that the hairs come with the skin, and continue to grow as if they were in-situ.

and then other parts of skin know not to grow hair at all!

Dragonflies are pretty much the best flyers among the insects, and they have four wings. Maybe not directly comparable, but still.

Generally, all insects have four wings, but they are not always used for flying.

Flies in particular are also among the best flyers, and yet, they use only two of their wings for flying, the other two shrank to became halteres, a sensory organ acting like a gyroscope.

Dragonflies may be the best fliers in the insect world thanks to their four independently controlled wings, but flies may be the second best, and they achieved that by losing two of their four wings. Evolution is interesting.

Another example of evolution deleting something instead of creating something. It is bizarre how many examples that people cite demonstrating evolution are actually demonstrating devolution.

Hummingirds are the best flyers among vertebrates, with only two wings. They can hover very precisely, and they can also fly backwards.

insects are so different from vertebrates (e.g. multi compartment bodies thanks to how they express the HOX gene) that the flying strategies are also quite different.

At the current level of O2 in the air I don't believe that flying insects can grow as large as even a hummingbird, much less an eagle.

"At the current level of O2 in the air I don't believe that flying insects can grow as large as even a hummingbird"

This got me curious. At a quick search, I found out that there in fact is at least a species of flying insect larger than (the smallest) hummingbird:

https://en.wikipedia.org/wiki/Gauromydas_heros

https://en.wikipedia.org/wiki/Bee_hummingbird

The insect grows up to 7 cm in length whereas the bird can stay less than 6 cm at adulthood. No information about the insect weight though (for a proper comparison).

Not always.

On two different occasions, I've had ingrown toenails that had to have a procedure done because, once they started ingrowing, they wouldn't stop doing so. (It's still outward growth but still.)

For others that have had this issue too: Cut your toe nails in a straight line. I used to cut them in a curved line, a 'C' kind of shape. Don't do that. Cut them in a '|' kind of shape. Yes, you'll have a big overhang on the edges, but give your toe time to adapt.

I've had a few of these procedures too and it never really stuck for me. Ingrown toenails kept being a problem. Then I started cutting my toenails in the flat / straight '|' sort of way and I've not have a problem since.

I figure it's worth a shout out to the few of you out there that need the help. But, again, it may not work for you too.

My friend told me this like 15+ years ago. I was skeptical but it really works. I then just use a file to take a bit of the edge off until its a curve

Wow, amazing. Why does this work? I would think that the nail bed has no knowledge of what the end of the nail is shaped like.

Ingrown toenails basically don't happen in cultures where people don't wear shoes.

I suspect the cause is socks or shoes pushing against the skin at the end of the toe, causing it to grow incorrectly over many months.

An untrimmed nail pushes any sock/shoe away, solving the issue.

It keeps the side from curling in and causing the irritation/cut that results in what we call ingrown toenail.

The nail doesn't change, rather the skin by the end of your toe does.

Despite the terminology, "ingrown" doesn't mean the nail grows in the wrong direction. The lunula continuously emits keratinocytes in a single direction; these form both the nail bed and the nail itself.

The "ingrown" phenomenon occurs well after the nail has formed (it's getting pushed out from the lunula end) and is due to a combination of your toe's (hallux I assume) ideosyncratic geometry and environmental conditions, likely, as another commenter pointed out, how you innocently cut your nail.

Sorry for the pedantry but when I worked in drug development I used to research the nail unit, which, it turns out, few people do.

The most interesting thing I've learned about nails is that they're now thought to be part of an organ — the enthesis organ [1], which is the tissue structures around the site where the tendon attaches to the bone. This is relevant to spondylarthropathies, some of which show up as nail changes many years before enthesitis occurs.

[1] https://www.enthesis.info/anatomy/enthesis_organ.html

i’ve had those procedures— super painful. i’ve ended up doing surgeries to cauterize the roots to prevent the ingrown growing direction.

Wasn't my experience FWIW. (Mostly commenting so others won't necessarily avoid.)

Just an in-office procedure using some local anesthesia and acid I think. The first time the whole cycle went on for months while I was regularly going to the podiatrist because of a fairly severe foot fracture of the same foot which may or may not have been connected.

This last time--a good 15 years later symmetrically on the other foot--I was pretty much just "Let's do this" after a couple times trying to just cut the toenail.

> Seems like it turned out to be optimal to stick to two, not just for terrestrial mobility, but due to the (bidirectional!) optimization of the wishbone and the chest musculature.

If they fly through the same air as airplanes, you also lose efficiency wherever you have wingtips (pressure below leaks above, basically), and the rear wings can get messed up by turbulence/vortices from the front wings if you're not careful.

> in humans

Nails are a much older "invention of evolution" than humans: so we have to investigate there...

> how do nails and hairs manage to grow only in one direction

Like all things evolution: nails that grow backwards to not have an advantage (prolly a disadvantage), where nails that grow forwards have an advantage (climbing, clawing, scratching).

"nails that grow backwards to not have an advantage (prolly a disadvantage), where nails that grow forwards have an advantage (climbing, clawing, scratching)."

That still doesn't describe the underlying mechanism of the growth itself.

Looking at the work of Dr. Michael Levin regarding electric communication of cells, I tend to believe him that the main factor in actually creating tissues in their intended, correct shape, is incessant electric chatter among individual cells.

An interesting corollary would be that cancer = cells that don't cooperate/communicate with their neighboring cells anymore.

Another interesting question is how development distinguishes left and right. As I understand it, there's a small object that develops that has cilia in a tilted configuration. The rotation of the cilia causes a flow of fluid to one side that is determined by the sense (clockwise or counterclockwise) of the cilia's rotation. That flow is sensed and sets off signals that drive development.

Where does the rotational sense of cilia come from? From the stereochemistry of proteins, and therefore from amino acids. The left-vs-right handedness of the base chemistry of life is exploited to get a macroscopic signal.

Wow, you amazed me. That is a journey of several orders of magnitude.

That journey of orders of magnitude is the journey of all life on Earth from its genesis to today.

I can't speak about nails and hairs specifically, but directional cell growth is common in nature.

In plants, for example, cells replicate primarily at the tip of a bud, which allows branches to lengthen directionally rather than grow out in all directions. The plant produces growth hormones, which are transported upward throughout all branches until they reach a dead end. When they reach a dead end, they stop moving and just sit there, which causes the cells at the dead end to have a greater exposure to these growth hormones. These cells bathe in growth hormones for so long that they pass the hormone-exposure threshold that triggers cell replication.

I hear this kind of “it exists because it has to exist” thing from non-bioscience types a lot. Essentially, this is just a tautological statement.

I don't read "it exists because it has to exist" in the parent's statement. They're saying that there's an advantage one way and a disadvantage another, and evolution favors advantages. I wouldn't characterize a statement like that as a tautology, and I don't think the author deserves your dig for it.

> and evolution favors advantages

The question was how, not why.

Your answer is like saying "how does the eye focus light" and answering "so that you can see".

In my opinion there’s a general fundamental misunderstanding on the purpose of theories. I see it all the time — attempts to explain why something is useful simply because it exists (re: popular science evolution). There are loads of suboptimal traits that are counterbalanced by something else.

Tautologies may be unsatisfying, but there's nothing specifically wrong with them.

It is what it is.

Yeah that’s not how it works. Fitness is not determined for every single attribute.

For example, observation A might be maladaptive, but it is caused by gene B which also causes observation C, which does provide an advantage.

> hatching ground in Alaska to its wintering ground in Tasmania

According to simulations of plate tectonics, these two locations would have been somewhat closer... 100m years ago.

Because nails and hair are produced at a fixed site. The nail itself is dead cells and do not grow.

That isn't the question (in a prior job I studied the physiology of the nail unit). Most cells don't normally have an orientation, so you'd think that thefollicle would push out a hair in some random direction, sometimes towards the outside world and sometimes in the direction of your bones.

Obviously they don't (!) but the question is how?

The nail is the same: the lunula emits these keratinocytes in only one direction; even more weirdly it's a planar structure.

> Obviously they don't (!) but the question is how?

Don't cells "just" orient themselves using mechanotransduction [1] or am I missing something? That's a bit hand wavey but since cells don't form 3d structures in tissue themselves, they orient against the extracellular matrix using mechanotransduction and other growth factors.

The development of multicellular life was essentially cells learning how to orient themselves into a digestive tract.

[1] https://en.wikipedia.org/wiki/Mechanotransduction

It's all designed. Top down, one mind. Designed. That's why it all works.

Think about all the cells, and the thousands/millions of jobs they do, in perfect coordination just in your fingers or hands.

It's all designed.

never thought I'd see a creationist on hn. Giraffe's have a nerve that goes all the way down the neck and back up, merely because it couldn't unwrap from a vein as giraffes evolved longer necks. No designer would include such a needless waste of resources. If there's a watchmaker, he's a blind idiot.

https://timpanogos.blog/2011/10/08/evidence-of-evolution-gir...

There is not some guy coordinating all our cells to grow and work in lockstep. It's actually just a few very simple algorithms (e.g., cells differentiation is triggered by strength of a signal, a la HOX genes) that have been very slowly refined over millions of generations of evolution.

Just because the output of a system looks complicated does not mean that the input into a system is complicated.

The most probable scenario for inorganic matter to be arranged and organised into a living, homeostatic self replicating machine, is for a number feature complete systems (including hardware and software) to appear all at the same time.

If you don't start with all of them in place, the organism dies, and fails to benefit from both time and natural selection.

Even in this model there are many chicken / egg scenarios. e.g. Every cell needs a membrane to survive, but how does a membrane benefit a cell if it has no ports built in to let waste out and food in? So the wall and the access control systems must appear simultaneously, or the cell dies and does not benefit from natural selection.

Another one is DNA, it's information storage, but it's inert, it doesn't do anything except be acted upon by other systems, but DNA holds the information to create those systems. So how were the systems consistently replicated before information storage systems like DNA?

You probably don't care about this because you seem to be answering something he didn't suggest... But he's not saying that every cell in our bodies is being actively managed by another being, he's saying that cells have been designed to self-coordinate.

Anyway, just food for thought for other readers who may also have these questions, you're not alone, and it is worth investigating because the current paradigm is in crisis and it's not worth basing your life decisions on their ideas anymore.

On what basis do you say that it is the most probable? It seems highly improbable to me that a mind could exist before living tissue exists, when every single example of a mind that we have studied depends on living tissue for its existence. It seems even more improbable to me that this mind could somehow intricately shape the universe. Through which mechanisms? Magic? The idea that lifeforms as we know then today were created whole cloth by an intelligent being of unclear origins and properties poses more questions than it answers.

On the other hand, there are plentiful examples of extremely simple lifeforms in nature, and there are also non-living things in nature that display phenomena that early simple lifeforms could have utilized (e.g., membrane-like structures that are spontaneously formed by phospholipids). There are still a lot of questions and unknowns here, but not nearly as many, and scientists are on a general trajectory of answering them at a fairly quick clip — whereas theological questions about the creation of living organisms are largely just as unanswered today as they were hundreds of years ago.

A different but popular notion is that a creator created the universe (effectively by sparking something like the Big Bang), but the lifeforms that followed evolved as scientists believe. This, to me, is far more plausible. As yet, we do not have any other good explanations for how the universe came into existence, and so this deistic hypothesis is as good as any other I have heard.

It’s a shitty designer that includes cancer et. al. in the spec.

exactly and clearly. Stray chance, dump nature ,blind force, unconscious casuality and the elements that without restriction are scattered in every direction -none of these can have any part in the most balanced,wise perspicacious, life giving ,orderly and firm deeds of the Creator. They are used ,rather by the command will, and power of the Glorious Doer as an apparent wil to conceal of His power.

According to the meaning of the verse: Who has created everything in the best way,(Quran)

everything is cut out according to its innate abilities with perfect measure and order, and put together with the finest art, in the shortest way, the best form, the lightest manner, and most practicable shape. Look at the clothes of birds, for example, and the easy way they ruffle up their feathers and continuously use them. Also, things are given bodies and dressed in forms in a wise manner with no waste and nothing in vain; they testify to their number to the necessary existence of an All-Wise Maker and point to that Possessor of Absolute Power and Knowledge

If the world warms back to the saurian sauna for a few millions of years, maybe mammals will not be on top of the game anymore. Time to welcome our new avian overlords. Maybe they'll evolve from crows. They're more optimal in so many ways anyway. Too bad they won't have coal, oil or natural gas reserves to build an early industrial civilization on.

But getting large amounts of copper, iron and aluminum will be so much easier with all the work we have already put into mining and refining it. At worst you have to invent the technology to turn wood into charcoal and charcoal into coke to get the fire hot enough to smelt iron. But aluminum is pretty rust resistant and can be smelted with a good wood fire, and avian species will likely prefer the lighter metal anyway.

> If the world warms back to the saurian sauna for a few millions of years, maybe mammals will not be on top of the game anymore.

Yes! I've been saying this. Global warming seems like a given at this point, so instead of stopping it we should try to increase oxygen levels too and then stick Bombardier Beetle fire-breathing genes in back-bred Hatzegopteryxes. Those beasts had wingspans over ten meters, were apex predators, and were built like it. May as well get some dragons to look at…

> Time to welcome our new avian overlords.

Not new. Birds are theropods, same as T-Rexes. It's just a return to form.

They have microplastics. Enough to power the new society for 200 years.

Excuse me - they have ample amounts of complex long-chain hydrocarbons helpfully globally distributed on the surface by humans (plastics).

https://archive.is/20240416202627/https://www.scientificamer...

Great article. But I hesitate to call feathers one of evolution's cleverest inventions. The natural world is chock full of amazing evolved engineering from the huge (the hearts of blue whales) to the intricate (the brains of hominids) to the diverse (the various forms of eyes from compound to pinhole, to lensed), to the tiny (white blood cells). Everywhere you look there are feats of engineering that would awe anyone.

I'd like to imagine if there's thousands of other worlds out there where evolution of complex life has played out. If you brought intelligent life from those places to Earth, what would they find most surprising?

I think feathers would be one of those things.

October 2022 a bird with the code name B6 set a new world record that few people outside the field of ornithology noticed. Over the course of 11 days, B6, a young Bar-tailed Godwit, flew from its hatching ground in Alaska to its wintering ground in Tasmania, covering 8,425 miles without taking a single break...

Many factors contributed to this astonishing feat of athleticism—muscle power, a high metabolic rate and a physiological tolerance for elevated cortisol levels, among other things.

Additional fun fact the article doesn't mention:

Birds sleep with only half their brain at a time when making these long distance flights. That's why they don't doze off and fall out of the sky.

Dolphins too. Half of their brain keeps them swimming while the other half sleeps.

Other fun fact: Humans making long car drives also do what's called "microsleeping". Your eyes remain open and your hands stay on the wheel, but your brain goes unconscious for a couple seconds at a time. Usually, you don't even notice…

How did scientists figure this out? Did they attach a flying bird to an MRI machine?

EEG for one.

https://en.wikipedia.org/wiki/Unihemispheric_slow-wave_sleep

> did not land, did not eat, did not drink and did not stop flapping

My understanding is that these incredible distances are achievable less by "flapping" and more by leveraging small adjustments to harness the incredibly powerful forces found among and between air currents and waves as they traverse across the ocean.

For example, here is an unpowered remote control glider achieving measured speeds of 548+! mph using nothing but natural energy harnessed from wind and gravity.

https://www.youtube.com/watch?v=4eFD_Wj6dhk

https://en.wikipedia.org/wiki/Dynamic_soaring

> My understanding is that these incredible distances are achievable less by "flapping" and more by leveraging small adjustments to harness the incredibly powerful forces

That is not correct. This particular bird (Bar-tailed Godwit) has never been observed to "dynamically soar" nor does it have the proper wing shape for that type of flight. If you ever seen Godwits in the wild, you will know why, it's a flapping only bird, they have no other mode of flight.

Albatrosses on the other hand do employ dynamic soaring and fly even greater distances than Godwit does (they can circumnavigate the Southern Ocean several times) although albatrosses have additional advantage of being able to use water for rest (Godwits cannot).

This is interesting. Let’s say 600g Bar-tailed Godwit goes on 13500 km flight and spends very optimistic 200g of fat. Theoretically, if fat is only used for going up, it can climb to 170km (i.e. potential energy). This means that to get to destination in needs to glide by dropping 12.5m per km, or have glide ratio of 80.

Best human gliders have glide ratio of 60. So Godwit still needs to be very efficient glider, or, what is more likely also knows how to use winds and updrafts.

Godwit does not glide at all. Its wings are physically too small to support any kind of gliding flight. It must flap constantly to stay aloft.

What this calculation shows is what glide ratio Godwit must have if it spends 1/3 of its body weight very efficiently to gain altitude and reaches destination in completely calm air. By the looks of it it doesn’t have this glide ratio, and I doubt it spends 1/3 of its weight only gaining altitude.

So it means that it must gain altitude and, perhaps, travel speed by alternative means, most likely using updrafts and riding winds.

Your calculation is interesting, but I beg you to go outside and look at how Godwits actually fly. Godwits fly in a straight line using rapid powerful nonstop flaps. They are relatively heavy birds with high "wing loading ratio" and their entire body plan is hyper-optimized for this type of flight and no other. This is especially true during migration when they accumulate lots of fat and their wing loading ratio is particularly unfavorable for soaring. Godwits are among the fastest-flying birds in a straight line, and they have never been observed to engage in any other mode of flight, nor can they. They cannot use regular soaring. They cannot use dynamic soaring. They do not fly like seagulls. Their wing area is simply too small to allow any other type of flight. They also typically do not wait for favorable wind to fly. They just take off and go.

I agree with your points. What this calculation shows that godwits must rely on favorable winds and updrafts (which benefit any flying object, including birds, since motion is relative); if this is not the case, they just not going to reach claimed distances given their weight and how much fat they are carrying.

It could also be that the numbers/assumptions input into the equations are incorrect but :)

Weight and distance numbers are from Wikipedia, potential energy formula is from school.

You are welcome to recalculate :)

You see this even more in the ocean. There are sharks who, being cold-blooded, have the ability to slow their metabolism to very near zero and simply ride a current for thousands of kilometers to entirely different parts of the globe where feeding is better without expending any energy to do it. It's probably why sharks have been around so long. They can be extremely resistant to famine conditions.

I met that guy at a glider meetup a few months after that record. That Transonic plane is huge. He managed to fit the 3m wingspan into a regular car, lengthwise.

I never got out to Parker Mountain but those guys had great stories. 100G will find the weak point on your model, often explosively.

Also fun is pelicans surfing: https://www.youtube.com/watch?v=cEFrSycTvRk

That pelicans surfing video is perfect - there's certainly not a whole lot of flapping going on.

100G will find the weak point on your model

You know, just a casual glider built to withstand 10 times more gravitational force than an F-15 and 15 times more than a Formula 1 car. Wild.

It is wild. It’s frightening when you see it.

But they’re also a masterpiece of weight reduction - the less mass, the less of a problem the Gs are. No big IC engine to deal with. The electronics are tiny and the fuselage walls are also super thin. It’s a stressed surface carbon fibre/kevlar frame to spread the force.

What I like is the common idea that only powered flight is fast. A propeller would only slow this model down. They’re so sleek.

My gliders are very casual — this one is a serious machine!

Really good article.

I know some of the early evolutionists wondered about the evolution of the feather and wing, since it seems hard to evolve in a gradual way -- a little bit of a feathery flap doesn't offer any advantages if it's not enough to glide on.

I know one of the leading theories is that they evolved to keep animals warm, since they're also good insulators. Is this still the main theory?

> it seems hard to evolve in a gradual way

There seems to be 4 different hypotheses. So there is no consensus on this question.

https://en.wikipedia.org/wiki/Origin_of_avian_flight#Hypothe...

A video about the "wing-assisted incline running" hypothesis:

"The Origin of Flight--What Use is Half a Wing?" https://www.youtube.com/watch?v=JMuzlEQz3uo

I have no knowledge in this area, this is purely a guess and so I am sharing it not to inform anyone but in the hope someone who does know can tell me if I'm wrong:

When I thought about this in the past, I assumed they evolved in sea creatures first - where even very small flaps or mini wings/fins could improve hydrodynamics and/or swimming control, without needing to make a single jump from useless to being able to fly. But I've not looked into whether that is the case.

Edit to add two quotes from a quick search:

"Thus, early feathers functioned in thermal insulation, communication, or water repellency, but not in aerodynamics and flight." - https://www.britannica.com/animal/bird-animal/The-origin-of-...

"Two major rival published theories are based on the roles of feathers in insulating the body against heat loss and in providing an aerodynamic surface for flight. However, because of the lack of knowledge about the roles and ecological relationships of protofeathers and of the most primitive feathers, it is not possible to test strongly either of these theories, or others as proposed in this symposium, against objective empirical observations to determine which is falsified or is the most probable" - https://academic.oup.com/icb/article/40/4/478/101404#

I love the science of evolution in that there's no need for an underlying model for such an invention to actually verify the science and the possibility of it, just that such an invention is possible. Basically anything and everything is possible with evolution and that doesn't really feel like science to me.

Indeed, evolution is basically trial and error, where the trial is life, and the error is (untimely) death.

I'd argue that it's not science at all, because what's missing is the coordination behind it. To me, evolution is not a product of conscious effort, but an emergent behavior or the individuals and systems that participate.

Taking the "science" definition from Wikipedia: "Science is a rigorous, systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the world". With evolution, testing definitely happens, but it's not a systematic endeavor, or at least I'm not convinced that it is.

To me, it sounds like science at its finest.

Only what works, survives, regardless of the politics, i.e. what others think of it.

Another feature that make birds really remarkable, if not mistaken, is that they take in oxygen when they inhale AND exhale. Feathers are great, but a creature such as B6 still needs a lot of energy to fly for 10 days straight.

It's more that their respiratory system is kinda circular. When we exhale, there's still a bit of gas in our lungs, and that reduces how efficiently we can extract oxygen. But the oxygen extracting parts of a bird's lungs are more like a heatsink, with air rushing past it in a consistent direction, rather than back and forth.

Bird lungs have separate pipes for inflow and outflow, while mammals use the same pipe for both. Bird lungs are also relatively rigid, and they use separate air sacks to do the pumping

So human lungs are piston engines whereas bird lungs are turbojet engines.

It's interesting that mammal lungs are inefficient for the same reason two-stroke piston engines are.

My wife has an African Gray parrot, it amazing sometimes to just watch him and see something that can be traced back all the way to the dinosaurs.

Pretty smart too - the recognize people and objects and uses association of the words - like when my one black cat (got two but he has white feet) enters the kitchen to check for food scraps he says "Get out" like I would.

He has no oil gland to lube his feathers since they are a tree dwelling species from the tropics but down feathers which break down into a fine dust when he grooms.

It may be misleading to look at only to the design of the feather. Flight and such a long and sustained flight can only happen because of the sophisticated programming. Evolution must be a great programmer too.

One with lots and lots of time on their hand and countless trial and error, and parallel projects.

> and countless trial and error

Is it countless though? Earth is "only" 4.5 billion years old with life appearing "only" 800 million years later, which seems pretty short for something chaotic and unorganized to self-organize into the nearly unfathomable sophistication we have now. Of course, humans are bad at grokking large numbers, and I might be too biased as a God fearing man... to be clear I don't deny the realities of evolution, but I currently tend to believe that as far as abiogenesis/evolution goes, life was "seeded" in some way on the planet, i.e. given a head start vs arising spontaneously from primordial soup within 800M years. I realize that this belief doesn't really contribute anything to the scientific discussion, just musing that 800M years to create the initial life seed doesn't seem that long considering we use super computers to simulate trillion+ iterations of various models and have failed to observe similar phenomenon in terms of self-organization without outside influence.

> I currently tend to believe that as far as abiogenesis/evolution goes, life was "seeded" in some way on the planet, i.e. given a head start vs arising spontaneously from primordial soup within 800M years.

It really depends on what you think the seed was.

The Earth is about 4.5 billion years old and we have pretty good records of life on it and the evolutionary steps that took place going about about 3 billion of those with reasonable evidence of life for another billion before that (the 800 million years later part that you reference).

So, if life got seeded onto the planet, it happened before then and would have to have been in the form of small carbon-based molecules.

There's some debate in the field if life evolved genetics first or metabolism first. But the 'seed' would be the same in both cases, it's just that the pathway to get to modern life would be different.

The most compelling case that I'm aware of for these small carbon-based molecules to originate somewhere other than Earth is this paper: https://biologydirect.biomedcentral.com/articles/10.1186/174...

Essentially they show that genomes have been doubling in size on average every 350 million years or so. If you project that math backward, you end with life starting, not at the beginning of Earth, but at the beginning of time, coinciding eerily with the Big Bang.

That points to a theory that carbon, water, and other elements we thought developed later might have been created earlier in the universe than expected. That would then point to the building blocks for life being essentially 'seeded' everywhere in the universe. Waiting to wake up as soon as conditions were right.

>Evolution must be a great programmer too.

Randomly mashing the keyboard, then running the code hoping that it doesn't crash? Not exactly what I'd have in mind when thinking of great programmers, but to each their own.

I still cannot compute evolution

Take chimps to humans : 6 millions years. 10 years to produce some offspring : that's only 600000 generations

To be a success, a mutation would be transmitted to an offspring, replace a large number of the existing population, and only then be followed by the next "worthy" mutation

I do not know how many mutations are required to transform a chimp into a humain

I guess the number are not working

An organic "feature" like flight or gills, or the ability to blink requires both hardware and software (to both create the hardware, and to run the new hardware.)

This, we're discovering, takes quite a lot of information. Organised, specific information in the correct order to harness maths, physics and chemistry to create a working feature.

To get such a feature off the ground by random point mutations using evolution by natural selection, each and every mutation needs to provide selective advantage, or it is discarded. Any progress to such a feature must start again from scratch.

There is a theory about how this can happen, it's well understood, but now we know much much more about how Biology actually works at the lower levels. So regarding the theory, people know that something needs to give, and it's not going to be maths, physics or chemistry, lets put it that way.

That's a great breakdown of feather technology. TIL...

I read it as "Fathers Are One of Evolution's Cleverest Inventions".

It completely made sense. I heard some research where starting about 500K year ago humans started to pair bond as a way to prevent mom and child mortality during and after childbirth and indeed Fathers are a clever invention. So yea, feathers are cool - fathers too! (for more info/reading here is a book suggestion: Eve)

One interesting fact that I recall, and that I didn't see in the article, is that evolution in some Owls traded off silent flight for the inability to fly when their feathers are wet. When there's an extended period of wet weather, owl fledglings may starve because their parents can't hunt.

is a feather a discovery or an invention? (am actual philosophical inquisition)

Happenstance, if you ask me.

And if we're talking philosophy, I think the feather doesn't exist at all, so it's even harder for me to imagine that it's a product of conscious effort. I imagine that what we humans consider feathers have near-infinite, similar-looking predecessors, proto-feathers, which differ so slightly from actual feathers that it's hard to say where the non-feather featherlike skin protrusions end, and feathers begin. What we can do of course is agree on such a line, but that further proves to me that feather is just a human concept, and that non-humans don't actually consciously interact with whatever we happen to call feathers.

So, feathers just kinda happened over time.

"Discovery" fits since we're just uncovering what's already there, not creating it. "Invention" is for stuff we actually make. Unsure if just a mistake or creationist perspective in the article.

Evolution.

"Survival of the fittest" doesn't mean "That gene was gorgeous like Mr. Universe, so he won!" It means "Life threw something at a wall and this is what stuck. It died less in the face of actual real world conditions."

After you winnow away all the failed stuff, you have stuff that works. Do it for millions of years and amazingly complex and elegant stuff can emerge from the process.

Discovery implies that it already existed before and it wasn't found yet.

I'd say invention is closer but does seem to imply agency.

I think feathers are the evolution here. Something evolved into a feather.

There really needs to be a third term for something uncovered by a process that otherwise would not have existed but wasn't created with intent.

Emergence?

Excited to anticipate next-gen airplanes with slotted wingtips and their vanes controlled by AI for optimal performance.

Also the new swimsuits inspired by penguin feathers.

Props for ships with knobs inspired by whale flukes.

Wow, they are so incredibly intricate, it's almost like they were designed....

Great article, I like owls even more now. Didn’t know they are that silent.

Doesn't clever imply a conscious designer? Not very scientific.

Remaining question: Are feathers better than fur?

Dinosaurs were actually Chocobo

Chocobo -> Dinosaurs -> Chicken

Checks out!

Cracks me up how everyone seems to think this is the result of randomness and not of intelligent design.

For real. I love how they can even call feathers the greatest invention without ever wondering who the inventor was. You can’t claim evolution is the inventor. Evolution is a description of a process, and anthropomorphizing it doesn’t make it possible of inventing anything. It’s similarly funny to me looking through these comments and seeing people marvel about the engineering and design of things like hearts and cells. Does nobody ever think to ask, who designed this? Who engineered this?

It would be like finding a watch someone had dropped on the ground and being like, “Wow what an amazing invention! It must have evolved over several thousands of years until it was able to accurately track the time!”. Or thinking that a chaotic natural process like a tornado could somehow assemble a car if it blew through a junkyard. Both of these are ridiculous arguments, but that’s what people claim evolution is like. After all, given enough time anything is possible? Right?

Voltaire : The universe embarrasses me, and I cannot dream that this watch exists and has no watchmaker.

And Voltaire did not know about all the maths behind matter and universe, the computer science behind DNA, the complexity of biochemistry...

To all the engineers here : work about causality, and the power of randmoness, be curious, do not take for granted evolution through randmoness, it makes no sense especially for an engineer who knows how codes work.

The idea must precede the code, and the right code can act upon the matter. The random code without idea has absolutely no chance to do anything valuable.

Invention is searching a problem space to find novel solutions to problems. Can you explain why such a search would require agency?

That’s not the definition of invention.

> a: something invented: such as (1): a device, contrivance, or process originated after study and experiment (2): a product of the imagination especially : a false conception[0]

Studying, experimenting, and imagining all require agency.

[0]: https://www.merriam-webster.com/dictionary/invention

So if a process produces a device such as a bicycle without agency, that process is simply not invention, correct?

You make me sad

Yeah, but evolution's most "clever" invention is consciousness, human brain and its highest state philosophy. It's all the work of evolution.

Evolution's most "clever" turn and invention is it achieving self-consciousness (we are its "self consciousness")

> The flat, broad, flight-enabling feathers we see across most of the wings and much of the body surface of living birds are called pennaceous feathers. (Fun fact: these are the feathers people used to make into quills for writing, hence the word “pen.”)

I get the author's point, I think, but the etymology of "pen" according to wiktionary.com:

> From Middle English penne, from Anglo-Norman penne, from Old French penne, from Latin penna (“feather”), from Proto-Indo-European péth₂r̥ ~ pth₂én- (“feather, wing”), from peth₂- (“to rush, fly”) (from which petition). Proto-Indo-European base also root of *petra-, from which Ancient Greek πτερόν (pterón, “wing”) (whence pterodactyl), Sanskrit पत्रम् (patram, “wing, feather”), Old Church Slavonic перо (pero, “pen”), Old Norse fjǫðr, Old English feðer (Modern English feather);[1] note the /p/ → /f/ Germanic sound change.

So pens aren't called pens because we used pennaceous feathers, but because they were made of feathers, period. At least that's how I get it.

"Pennaceous feather" is a funny term too, then, meaning something like "featherlike feather"?

The article has another factual error as well:

>covering 8,425 miles without taking a single break. For comparison, there is only one commercial aircraft that can fly that far nonstop, a Boeing 777 [...]

The Boeing 787 and the Airbus A350 have ranges exceeding that, with ranges of up to 8,790 mi and 11,163 mi respectively, depending on the variant.

https://en.wikipedia.org/wiki/Boeing_787_Dreamliner#Specific...

https://en.wikipedia.org/wiki/Airbus_A350#Specifications

edit:

Turns out there's even more aircrafts that exceed that range.

https://en.wikipedia.org/wiki/Airbus_A330neo#Specifications

https://en.wikipedia.org/wiki/Airbus_A380#Specifications_(A3...

https://en.wikipedia.org/wiki/Airbus_A340#Specifications

I live outside Boston and frequently see a Newark-Singapore A350 fly over. A mind boggling distance…

> "Pennaceous feather" is a funny term too, then, meaning something like "featherlike feather"?

I'd probably render it as more like "typical feathers" or "standard feathers". Note that "typical feathers" and "feathery feathers" mean the same thing, but one is perfectly normal phrasing and the other isn't.

> from Latin penna (“feather”)

Also in Italian. Although I believe penna can also mean the more modern "pen."

Penne pasta is basically plural of this.

...and penknives were originally the small blades one used for trimming pennaceous feathers into writing-pens.

In Spanish. Pen=Pluma. Feather=Pluma.

In Mandarin Chinese a pen is 笔, obviously derived from the word for a paintbrush, 笔. Feathers don't come into it - Chinese is traditionally written with a paintbrush - but the pattern is the same.

I first thought the headline was “Fathers are one of evolutions cleverest inventions”. To which I agree

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'Gospel' means you don't have evidence for something or can't prove it practically, meaning it relies on story/word of mouth, which is why it's generally associated with religion and not science (or should not be anyways).

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Well, as somebody who likes complaining, I don’t like your new title either; evolution doesn’t ‘invent’ anything, and anthropomorphising it just confuses people (see also generative ai, grumble mutter).

Oh, I agree! But I did not want to make more than one change at a time ;)

> evolution doesn’t ‘invent’ anything

Really? I think it kind of does invent. Trial and error. Back propagation. Mutation. Some randomness at conception. Sure it's a personification, but not a bad one.

Evolution doesn't do back propagation.

The evolutionary fitness of a particular adaptation helps spread the genes that causes the adaptation. I think backpropagation is a very apt description for that phenomenon

That's propagation.

I stand corrected. Thanks.

There is zero science to back that up, natural selection ≠ evolution.

What a pedantic take. I’m sure you would prefer a lot of things, but changing the title of an article you didn’t write or publish is a stretch. The articles showing off a very interesting aspect of nature and ‘one of [the] cleverest inventions’ is a fine headline without questioning how many other ‘inventions’ have occurred that might also be clever in the hopes of changing it. They’d also be ‘one of the cleverest’ if and when they get their own article.

I thought this was a aaron comment at first, then I saw a reply button, and whitewashed comment below.

I'm sorry, but no: such comparisons make for clickbaity headlines. I don't like clickbaity headlines.

> Pet peve: I don't like superlative descriptions. They're often counterproductive, because they call for a rebuttal.

Pet peeve: People who HAVE to rebut things like superlative descriptions. They're always counterproductive, because literally nothing actually called for a rebuttal. It clutters up the conversation much worse than "well, actually" corrections.

>literally nothing actually called for a rebuttal

Aside from the initial false claim, you mean?

> Aside from the initial false claim, you mean?

Well, yes, we're talking about the superlative in the title. Everything else might be nonsense and is fair game.

I thought "one of" is a weasel qualifier here?

Indeed, but it still unconsciously invites controversy (in my opinion) ¯\_(ツ)_/¯

i don't like people who spam "well ackkktually" and make it so entire categories of phrases need to be eliminated to appease their neurosis.

It's a form of tone policing ... "I don't like superlatives so you don't get to use them."

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Hi theodorejb!

The article did not take the time to do a deep dive into feather evolution so it could focus specifically on the topic of how marvelous modern feathers are. However if you are interested in the fascinating topic of the evolution of feathers there are some great resources available.

For a quick skim, this paper is quite good:

https://www.cell.com/trends/ecology-evolution/abstract/S0169...

But for deeper dive, this book is quite excellent

https://books.google.ca/books/about/The_Evolution_of_Feather...

I hope you enjoy these resources,

Cheers!

Taken in isolation it’s an interesting point, but with the long history of every evangelical saying the same thing for two hundred years and being found to be wrong, a lot less interesting.

What are you referring to when you say "and being found to be wrong"? I'm genuinely curious.

So you can't imagine how it evolved therefore you pick an even more unimaginable possibility with no evidence at all.

I mean maybe an ancient alien wizard did it. Should we credit the alien magi instead?

From my perspective God has given us an incredible amount of evidence for His work - it's all around us in nature if one is open to looking for it!

Why isn't that the work of an ancient alien magi? Seems like the evidence for the alien magi is equal to the evidence of God.

The natural world truely is beautiful, and it's no surprise that someone would ascribe the majesty around us to higher powers. In fact, many scientists throughout time have been inspired to pursue scientific endeavors as a way to view the mind of God (and/or God's, depending the religious beliefs of the individual). However, we do God(s) a disservice when we deny the intricacies of their creation of the universe in favour of overly simplistic shortcuts such as "feather good because God made it". The story of natural selection via evolution is marvelous, and I don't believe that the God that made this universe would want us to ignore the intricacies of this fascinating process in favour of thought-terminating explanations such "well, it was just made that way".

I also don't believe that God has an interest in deceiving us. Which would be the only explanation to reconciling a Creation explanation with the overwhelming amount of evidence for natural selection.

Natural selection is certainly real, but it has zero creative power. It can only select from what already exists. Usually the actual creative mechanism is assumed to be random genetic mutations. But where has anyone observed mutations changing one kind of animal into a new more advanced kind? In reality mutations are destructive to genetic information, and over long timescales cause devolution. As more mutations are inherited, genetic disorders and diseases will increase. To learn more about this I recommend reading the book "Genetic Entropy" by Cornell University geneticist Dr. John Sanford.

I strongly disagree that it's thought-terminating to believe that God designed the universe and living things. This understanding will lead scientists to study the genius constructions, techniques, and formulas that God used in order to improve our own machines and inventions. In contrast, the belief that living things evolved by chance may cause scientists to dismiss something they don't understand as a useless evolutionary leftover, rather than studying it further to find its actual purpose (e.g. the appendix). Thus evolutionary assumptions retard scientific progress.

Many organisms have been observed to acquire various new functions which they did not have previously (Endler 1986). Bacteria have acquired resistance to viruses (Luria and Delbruck 1943) and to antibiotics (Lederberg and Lederberg 1952). Bacteria have also evolved the ability to synthesize new amino acids and DNA bases (Futuyma 1998, p. 274). Unicellular organisms have evolved the ability to use nylon and pentachlorophenol (which are both unnatural manmade chemicals) as their sole carbon sources (Okada et al. 1983; Orser and Lange 1994). The acquisition of this latter ability entailed the evolution of an entirely novel multienzyme metabolic pathway (Lee et al. 1998). Bacteria have evolved to grow at previously unviable temperatures (Bennett et al. 1992). In E. coli, we have seen the evolution (by artificial selection) of an entirely novel metabolic system including the ability to metabolize a new carbon source, the regulation of this ability by new regulatory genes, and the evolution of the ability to transport this new carbon source across the cell membrane (Hall 1982). Such evolutionary acquisition of new function is also common in metazoans. We have observed insects become resistant to insecticides (Ffrench-Constant et al. 2000), animals and plants acquire disease resistance (Carpenter and O'Brien 1995; Richter and Ronald 2000), crustaceans evolve new defenses to predators (Hairston 1990), amphibians evolve tolerance to habitat acidification (Andren et al. 1989), and mammals acquire immunity to poisons (Bishop 1981). Recent beneficial mutations are also known in humans, such as the famous apolipoprotein AI Milano mutation that confers lowered risk to cardiovascular disease in its carriers.

Bacteria, plants, and other creatures are incredibly well designed to be able to adapt for survival in different environments, to the extent they can even copy and use external genes in some circumstances. Yet they still always reproduce the same kind. E. coli produce E. coli, plants produce the same kind of plant, animals produce the same kind of animal. There can be a lot of variation within a kind (e.g. all the different dog breeds), but a dog will never produce a non-dog, and a fish will never produce a non-fish. This requirement of microbe-to-man evolution contradicts the fundamental law of heredity.

> but a dog will never produce a non-dog, and a fish will never produce a non-fish. This requirement of microbe-to-man evolution contradicts the fundamental law of heredity.

Agreed! And doing so would of course invalidate our current understanding of how evolution works! We'd have to throw out our theory of evolution by natural selection if we ever observed a dog give birth to a non-dog!

The definition of a "species" isn't something defined by nature. Rather it's a construct that humans invented in our need to categorize things. Genetic dissimilarities one generation to the next are of course very very small. So small that adjacent members will always be of the same "species" (able to breed with each other). But cumulative changes over generations add up. So much so that if we skipped ahead many generations, we'd no longer have compatible breeding. Different "species" as we would say under our admittedly flawed categorization system. At what point in the family tree does the species change? Given that each species can breed with its adjacents? At what point does a color gradient stop being red and start being blue? As you can see, the flaw in this understanding stems only from holding onto the definition of distinct "species" as something real rather than a human creation. A useful one, don't get me wrong! But it's important to understand the fuzziness of this definition. Your argument stems from a fundamental misunderstanding of this idea.

By the way, the example above is not merely hypothetical, since species can be separated in space as well as time. We can observe this phenomenon in action through very fascinating phenomenon like "ring species".

https://en.m.wikipedia.org/wiki/Ring_species

Really cool stuff! I'd highly recommend learning about it.

Why would natural selection require creative power? It doesn't require any intelligence at all -- just a harsh environment that makes it more difficult for less effective / efficient random iterations to survive. Then multiply that by hundreds of millions of iterations.

Dismissing a feature as leftover isn't the fault of evolution -- it's a fault of the scientist. There should at least be a potential former use identified. But that doesn't make evolution less viable.

The evidence that you claim is missing for genetic mutations increasing complexity over long-time frames is simply not supported by the wealth of evidence from multi different disciplines. I'm sure Dr. John Sanford is quite persuasive, but the words of one individual do not refute the decades and centuries of evidence that dispute this.

It is indeed thought terminating to continue to hold a belief if it is not supported by evidence. The idea that organisms were formed more or less as they are, and that natural selection is only capable of minor adjustments is something that is empirically testable by observing genetic lineage, and the fossil record. But the hypothesis fails under the weight of our observations. It does really appear that organisms have a direct lineage all the way back to the most primitive forms of life. In light of this, we must reject the hypothesis and accept what the evidence tells us. To do otherwise is allow dogma to cloud our judgement.

I know I said this already, but I'd like to repeat my opinion on the intersection between religion and science: I do not believe that the creator of the universe would want us to reject the tools that they have given us to understand their universe. To do so would be to dismiss and condescend their achievement. So why do you choose to do this with evolution? Despite it being one of the most well-supported scientific theories we have? As you mentioned, you accept natural selection, so clearly you accept aspects of the theory despite it contradicting your theology. I'm sure your beliefs contradict your theology all the time across many aspects of your life. Surely you accept that a text from the bronze-age written by fallible humans and influenced by the ideas of the very specific culture that produced it is not literally 100% true?

I choose to agree. To close ones mind to a conclusion (that there is a creator) is as illogical as blindly assuming there is a creator just because somebody said there was.

One of the things that's always baffled me, and I say this completely honestly, is that if somebody looked at something like a Boeing 747, any high rise building, or well constructed, artistic looking bridge, and said "wow, evolution is amazing!" we would think them insane. But do that with something as intricate as a feather, or the brain (of any animal) and it's immediately acceptable.

Then there's the second law of thermodynamics, which seems to be ignored by evolution, where it seems to be accepted that entropy decreases over huge amounts of time.

The second law of thermodynamics doesn't apply to a system where we are constantly adding external energy.

If we start we just a handful of seeds and externally add energy in the form of sunlight then over eons we will have a massive forest that covers the globe. That doesn't disobey the second law of thermodynamics.

Our planet has continuous inputs of external energy.

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well ... I believe that this pencil on my desk did evolve over thousandtrillion years so you should do. We don't know why this simple pencil did evolve but somehow this did happen. Just believe and at this time don't be Mr Spock.

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In response to your comment, it's important to clarify several misconceptions about evolutionary biology and the synthetic theory of evolution. This theory is not a scam nor inherently atheistic; rather, it's a scientific framework that integrates genetics with Darwin's theory of natural selection to explain biological diversity.

First, evolution, through natural selection and genetic variation, is indeed capable of innovation. Complex structures and functions can arise incrementally over time. Features that provide a survival or reproductive advantage are more likely to be passed on to subsequent generations, gradually leading to complex adaptations.

The analogy of DNA needing to be like a program, CDROM, reader, and printer all in one cell is an oversimplification that misunderstands molecular biology. DNA replication, transcription, and translation are complex processes facilitated by a variety of proteins and enzymes, which themselves evolved.

Regarding Prof. Michael Behe's arguments in "Darwin's Black Box," while thought-provoking, they have been widely critiqued and refuted in the scientific community. Behe's concept of "irreducible complexity" has been shown not to preclude evolutionary origins, as numerous studies have demonstrated how complex biochemical systems can evolve from simpler precursors through natural processes.

Lastly, it's critical to approach scientific topics with an understanding based on evidence and consensus among experts. While there are always unanswered questions in science, the theory of evolution remains one of the most robust and universally accepted scientific theories, based on overwhelming evidence across different fields including genetics, paleontology, and molecular biology.

Exact : The Program, CDROM, CDROM reader, and 3D printer all in one in a single cell is over simplification. It is far far more complex mechanisms that cannot emerge from random mutations.

Evolution is a fact we can all see, but the engine of evolution (random mutations) is an unproven theory.

For those who have curiosity, and most engineers should have : Michael Behe was challenged by "Evolution a theory in crisis" by M. Denton

Your portrayal of evolutionary processes oversimplifies the intricate dynamics at play. While you emphasize the complexity of cellular mechanisms, suggesting that such complexity cannot arise from "random mutations" alone, you overlook the essential role of natural selection. This process is anything but random; it is the methodical mechanism through which advantageous traits are favored over time, shaping complex biological forms.

Moreover, referencing Michael Behe's concept of "irreducible complexity" and Michael Denton's "Evolution: A Theory in Crisis" does little to undermine the robust body of empirical evidence supporting evolutionary theory. These critiques, while provocative, have been extensively rebutted in peer-reviewed research. The consensus among biologists is clear and based on a wide array of studies—from genetic sequencing to fossil records—that collectively validate evolutionary theory.

To dismiss evolutionary biology as an "unproven theory" is to ignore the comprehensive and corroborative data gathered over decades. Such a stance not only misrepresents the nature of scientific inquiry, where theories are continually tested and refined but also underestimates the adaptive power of natural processes documented in both the laboratory and the wild.

The fact that you can't envision a world where natural forces produced all of this and the reductiveness of your argument demonstrates a profound lack of imagination and an unwillingness to engage with possibilities that challenge your world view. We suspect all of this evolved over eons because we can see it writ small in the changes that organisms undertake even today, and we extrapolate to the eon because we can see these changes play out in a fossil record to produce entirely new kinds of creature. Saying that this is simply impossible without providing any alternative explanation for the evidence asks us to take too much on faith. If you're going to say that the great body of research and evidence led us to the wrong conclusion you now have the task of explaining, for each piece of evidence, what the alternative explanation is and how your explanation is better than ours.

to be fair I don’t see the research itself favoring evolution over creationism in any sense, which is notable because of course the poster mentioned atheism, it’s just that we have a desire and tendency to take research and turn it into a story, when really all the research we don’t have is so strikingly vast that it makes it kind of silly to craft an ongoing story based on such tiny amounts of data, but it’s human nature and fun, but leaning into it too much forgets that one new discovery can toss the entire story, science just isn’t meant for building confident origin narratives for that reason, it’s a very tiny scoped view of things on purpose, by the very nature of the scientific method

example: based on our limited understanding all we can seem to confirm so far is that there was a sort of “big bang” but that doesn’t mean a “big bang” is all there was, not by a long shot

There is no alternative scientific explanation, there is a demonstrated proof that part of the synthetic theory of evolution is false. Evolution is a fact, but random mutations cannot be the engine of evolution, they do not have this power of innovation.

Prof J. Tour (great biochemist) who devoted his life to build synthetic molecules, never ceased to explain this. Mutations break the program (DNA) and cannot create new proteins, new mechanisms, and new coordinated organs, not to say new species. Enginneers here should understand this as I do.

Many organisms have been observed to acquire various new functions which they did not have previously (Endler 1986). Bacteria have acquired resistance to viruses (Luria and Delbruck 1943) and to antibiotics (Lederberg and Lederberg 1952). Bacteria have also evolved the ability to synthesize new amino acids and DNA bases (Futuyma 1998, p. 274). Unicellular organisms have evolved the ability to use nylon and pentachlorophenol (which are both unnatural manmade chemicals) as their sole carbon sources (Okada et al. 1983; Orser and Lange 1994). The acquisition of this latter ability entailed the evolution of an entirely novel multienzyme metabolic pathway (Lee et al. 1998). Bacteria have evolved to grow at previously unviable temperatures (Bennett et al. 1992). In E. coli, we have seen the evolution (by artificial selection) of an entirely novel metabolic system including the ability to metabolize a new carbon source, the regulation of this ability by new regulatory genes, and the evolution of the ability to transport this new carbon source across the cell membrane (Hall 1982).

Such evolutionary acquisition of new function is also common in metazoans. We have observed insects become resistant to insecticides (Ffrench-Constant et al. 2000), animals and plants acquire disease resistance (Carpenter and O'Brien 1995; Richter and Ronald 2000), crustaceans evolve new defenses to predators (Hairston 1990), amphibians evolve tolerance to habitat acidification (Andren et al. 1989), and mammals acquire immunity to poisons (Bishop 1981). Recent beneficial mutations are also known in humans, such as the famous apolipoprotein AI Milano mutation that confers lowered risk to cardiovascular disease in its carriers.

These are not random mutations but adaptation features. In the E. Coli LTEE (Long Time Experiment) still ongoing, 65 000 generations since 1988 have shown little adaptations (like epigenetics) but they are still E. Coli, not another bacteria, nor another species.

How do you define "species" because there are things like ring species that break the mold of basic definitions.

https://evolution.berkeley.edu/a-closer-look-at-a-classic-ri...

As you go along the ring you can easily observe the creation of new species through evolution that can't breed with each other.

> there is a demonstrated proof

Where?

Read Prof. Michael Behe, Prof M. Denton, Prof. J. Tour, PhD D. Axe and so many.

Nah. Onus is on you to provide evidence to back your claims.

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It is not, my account password did not work and I had to create a new one.

DNA is a four state bits program. Can you tell us how random mutations on a computer program (DNA) can create new proteins and new functionnal organs. What happens if you do so on a Windows or Linux program ?

IDK if you know this, but unproven theories are gospel around here.

archive link plz

Just append archive.is/ to the beginning of the url. Chances are, it is already archived. https://archive.is/https://www.scientificamerican.com/articl...

Or save a bookmark in your browser and edit its destination to be this Javascript bookmarklet to let you load the archive.is version of any URL you're currently on without even needing to remember the domain or type anything:

  javascript:void(location.href='https://archive.is/?run=1&url='+encodeURIComponent(location.href))

  javascript:void(window.open('https://web.archive.org/web/*/'+location.href))

Or this more complicated version of the Wayback Machine one, which if you click while on an empty tab will instead give you an alert with a text field in which to type or paste whatever URL you want to look up:

  javascript:(function()%7Bif(location.href.indexOf('http')!=0)%7Binput=prompt('URL:','https://');if(input!=null)%7Blocation.href='http://web.archive.org/web/*/'+input%7D%7Delse%7Blocation.href='http://web.archive.org/web/*/'+location.href;%7D%7D)();

Thank you, that's so convenient!

You're welcome :)

I'd say DNA is one of evolution's cleverest inventions, buuut. xD

*ducks*

Two things can each be one of evolution's cleverest inventions

So you're saying that two can be one?

2 = 1 proven?

They are saying "one of" does not mean the only one.

One of my cat's eyes is blue. One of my cat's eyes is green.

Both can be true at the same time.