Feathers came first, then birds

https://phys.org/news/2019-06-feathers-birds.html

by lelf • 7 years ago

41 88 7 years ago

fit2rule• 7 years ago

So, this settles it. The egg comes first.

misnome2• 7 years ago

It's always been the egg. The egg is laid by a proto-chicken and has the genetic mutation required to tip it into the "chicken" classification.

saalweachter2• 7 years ago

Is a chicken-egg an egg laid by a chicken or an egg that yields a chicken?

dictum• 7 years ago

It just occurred to me that the chicken-and-egg problem, Schrödinger's cat and the ship of Theseus are essentially the same question, with slightly different contexts.

EGreg14• 7 years ago

Seriously though, I have done a bunch of “wikipedia research” on how flight evolved. It’s all a bunch of “just so” stories and theories, which struggle to prove any evolutionary advantage to intermediate forms that can’t achieve flight or even gliding.

I think the evolution of flight is one of the clearest examples that the standard theories of evolution purely by mutation and natural selection are still lacking explanatory power. I understand that the theory of Common Descent has ample evidence but let’s not conflate that with the other theories (about HOW genetic drift happens in macroevolution) and turn “evolution” into a religion in our quest to replace creationist accounts. It is a catch-all umbrella term to describe many theories, from “punctuated equilibria” to the “modern synthesis”, which still are in their infancy as the luminiferous aether or phlogiston as physical theories.

I find there is too much suppression of dissenting views in evolutionary and climate science, for my taste. I am talking about universities and publishers taking concerted political action against what is perceived as going against the current establishment.

A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it. - Max Planck

In many circles, publishing anything critical on scientific grounds is like publicly criticizing capitalism in USA or Islam in Saudi Arabia. A lot of time you get instant downvotes and hostile responses from laypeople.

If you’re curious what I’m talking about, here is probably one of the better treatments of the mathematics behind current theories, for example: https://www.amazon.com/dp/1880582244/ref=cm_sw_r_cp_api_i_r....

pif• 7 years ago

I find there is too much suppression of dissenting views in evolutionary and climate science,

I think idiots are not ignored enough in our current society.

Science is about what can be observed. Theories are only useful as long as they predict right results. Opionions are irrelevant.

EGreg14• 7 years ago

Exactly. Theories are only useful as long as they predict right results. That’s what separates, say, the theory of common descent, from the current crop of theories about HOW flight evolved. They have ZERO predictive power. They are closer to “just-so” stories. Such theories should be rightly called unscientific compared to theories that have far more falsifiability and predictive power.

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

tylerjwilk002• 7 years ago

Here is an intermediate form theory I just came up with as I read your comment.

FALL SURVIVAL THEORY OF WING EVOLUTION

Any tree dwelling creature is at risk of falling and dying. Creatures that can better survive a fall (proto-wings, etc) have an improved chance of propagating this trait to off-spring. Furthermore, if they can better survive a fall they can risk higher climbs. The higher climbs make them better able to avoid predators and hunt prey further increasing selection pressure on fall survival and would dovetail nicely into gliding mutations. From there it is not a far jump to flying [pun intended].

No theory about the deep deep past can ever be certain. We weren't there to watch it happen.

EGreg14• 7 years ago

That just illustrates my point. The ability to come up with THEORIES is not the same thing as validating SCIENTIFIC theories which are falsifiable. Just because it’s easy to come up with a theory off the cuff means there is a lot more work to do in actually explaining how something happened. Phlogiston and Luminiferous Ether were two theories in physics that actually had WAY MORE evidence for them than these, but turned out to be wrong.

What separates a mere theory from a scientifically validated theory is falsifiability and experiment:

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

1e-92• 7 years ago

I think it is quite plausible that feathers originally developed for thermoregulation. If they started as simple filaments that could be raised and lowered to adjust radiative surface area, it seems that thermoregulatory advantages alone could have driven a series of small evolutionary improvements towards flat, light-weight feather-like structures. Seeing a bird able to massively fluff up its feathers or pull them in tight against its body is like seeing a person instantly go from wearing a puffy down coat for winter to a sleek body suit for summer exercise. From there, I can imagine how these flat, controllable surfaces could be used by small animals to eventually control rapid descent from trees to escape prey and then eventually evolving to flight.

EGreg14• 7 years ago

We can certainly explore that theory, but what can you suggest as falsifiability criteria? Flight evolved several times, presumably, including in insects and in mammals without feathers:

https://ucmp.berkeley.edu/vertebrates/flight/bats.html

Notice:

We can infer that bats gradually evolved true flight from a gliding arboreal ancestor, possibly using the gliding membrane as a sort of "net" while the flight stroke evolved.

We can infer this because we beg the question, i.e. the only way evolution can happen is random mutation and natural selection. And so, we postulate the theory as true fact and then we get the result that it must have happened some way that is consistent with the theory.

I am just generally remarking on the fact that all that seems to be required in today's scientific environment is to describe what could have happened with some arboreal ancestor gaining, say, webbed wing-like arms for some reason, and then over thousands and millions of generations for some reason, before the webbed arms could help them glide, they were accepted instead of shunned by their mates for their mutation, and the mutant population survived and genetically drifted in that direction, until finally they could glide... and then fly.

JoeAltmaier4• 7 years ago

Or even courting rituals! I like that route because, something terribly unrelated to survivability (ostentatious display can attract predators, signals mating suitability because the male can survive the cost of the display) becomes a wonderful adaptation. No evidence for this of course, but it makes a great just-so story

Scarblac7• 7 years ago

The theory of gravity doesn't try to explain where every apple that ever fell from a tree landed exactly.

foldr14• 7 years ago

No, and part of the reason that it can't is that the apple is subject to forces other than gravitational forces.

JoeAltmaier4• 7 years ago

Isn't DNA comparison between species supposed to get some idea of what came first? Shouldn't we be able to answer Which Came First, feathers or flight?

ncmncm10• 7 years ago

It's a dumb question, really. What would they use to fly with, before the feathers -- pixie dust?

There is a legitimate question: what did they use feathers for, before they used them to fly with? Because nobody ever grew feathers just because they wanted to fly real bad. All kids try it. Doesn't work.

It turns out feathers are really, really useful for all kinds of things, if you look. So, "what else are feathers for?" doesn't narrow down much how it led to flying.

We know how squirrels, frogs, fish, even tree snakes get lots of reproductive fitness by catching air. Best bet is, it was something similar.

Nailing down the exact process will take a hell of a lot of fossils.

Then we can start on pterosaurs and bats which don't, you know, use feathers.

_ea1k• 7 years ago

I don't have much to add to this, but I am amazed that basically every comment that you've made in this thread is downvoted, while almost none of the others are.

It isn't necessarily that you are right or wrong, but your thoughts are interesting and well presented and yet they have managed to prick some intrinsically negative emotional response.

Human nature... sigh.

ncmncm10• 7 years ago

No, it's just that we have seen this dance plenty of times before. None of it is ever original. It's all cribbed from the same tired script: "phlogiston" this, "ether" that. Ultimately it always leads to, "but how can you know, really know?"

The intent is always the same, too: Not to evoke subtle insights, or to open up new vistas of thought; but to gather in the pigeons who crave really knowing, and fatten them up on deception.

Concealing subtext doesn't mean there's no subtext.

BS presented well is still BS.

There is far more to know than science has ever even looked at. Not because it's not interesting, useful, or earthshaking, but just because science is hard, and we've been at it for less than 1000 years.

There is plenty that science's best efforts had wrong and improved upon, and plenty that's still wrong. Not because we're blinkered and pigheaded (although everyone is) but because it takes time, and we don't each have much, while jokers like this, congratulating themselves on their cleverness despite never having had a single original idea, waste it.

Do I sound disgusted? Yes, I said I have seen this before.

mikorym• 7 years ago

I thought that this was known already? But I guess that this is the Feathers Could be First (2019) version.

ncmncm10• 7 years ago

Kind of obvious, of course.

For a while there was a "Birds Came First" insurgency, insisting birds were not in Dinosauria because ... well, because they liked birds but hated dinosaurs? The argument never made sense, and it finally died down.

People who like birds and hate dinosaurs are like people who like tetrapods and hate fish. It's allowed, but not something for vertebrate biologists to pay attention to.

Balgair• 7 years ago

PBS's Eons is a great Youtube channel that covered the evolution of feathers.

https://www.youtube.com/watch?v=aOeFRg_1_Yg

Feathers came first, then birds

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