Wings, how long would it take to evolve them and other questions...

[Jonathanaronda]

Hi all, I'm a layman when it comes to science but I do want to learn more. I wanted to know if humans were to evolve wings (for whatever reason), how long would the wings be? What changes will come in their body? Say the wings were to evolve angel-like... would that be possible?

 

And probably my most important question, how long (years) would it take for them to evolve those wings, if the process started now? 100,000? 200,000 years?

 

Sorry if this question has been asked before.

[Phi for All]

When you say "angel-like", do you mean arms turning into wings or do you mean wings sprouting up from somewhere towards the back, independent of the arms?

 

Arms and wings are modified legs, essentially, so we'd somehow have to grow two new "legs" to be modified by selection into wings. Although I would imagine the selective pressures would be more likely to give us a second set of arms, given our current environments.

 

I don't think there are any examples of a six-legged vertebrate.

[Jonathanaronda]

When I said angel-like I meant somewhere towards the back. But I've learned in science, its never that simple then just growing wings on your back and you'll fly. There's more to it then that.

[Phi for All]

Wings, being modified legs, require a whole set of musculature all to themselves. And avian creatures are much lighter weight with lighter bone structure than humans.

 

All that aside, there really isn't any selective pressure for us to evolve wings. We just don't need them, no matter how cool it would be to fly. There is nothing about our current ecology that would make wings desirable. We'd have to change everything about the way we live in order for wings to make us more successful at survival.

[Jonathanaronda]

Well let me give you a scenario... say a huge flood hit the world (think of the movie: The Day After Tomorrow) and it wiped out a lot of life and wiped out lands, forcing humans to take life in the water by use of boats. Would that be enough selective pressure for us to evolve wings? And if so, how long would that take?

 

Sorry, if the scenario sounds stupid, again, I'm only a layman to science... but I am fascinated by this question.

[Phi for All]

In that scenario, I think the first mutation that would gain from natural selection would be webbed fingers and toes. More successful swimmers would get more food, become stronger and reproduce more successfully. After that, perhaps some kind of webbing that stretches between arms and legs, like a flying squirrel, may give both added swimming control and a limited gliding ability.

 

Again, we have no examples of a six-legged vertebrate, so growing an extra set of limbs that may get modified into wings is an unrealistic stretch. Remember, wings don't evolve by themselves, they're modified legs. We'd require a completely different skeletal and musculature model to warrant having six limbs. This would require extra growth and in your flood scenario you just reduced a huge portion of our food supply. I think the tendency would be towards smaller humans.

[CharonY]

For extra limbs it is impossible to make any assumptions. For regular wings one could estimate the minimum time by looking at involved genes (which is also not known actually, but the info is at least theoretically there) and look at the sequence divergence between i.e. bat and humans. Of course you still would not be able to fly as you would be too heavy and the scaling is not likely to be favorable. But at least you would look weird.

 

Also this belongs to speculations.

Edited April 24, 2012 by CharonY

[Jonathanaronda]

I see. Thanks. So in that scenario, we'd become swimmers not airborne. Makes sense. Thanks!

 

 

Would love to get some other opinions and/or some more understanding about wings.

 

 

By the way, Phi for All, you say that if we evolved wings, we'd become smaller. Does that mean that's what happen to the dinosaurs? It took a catastrophic event to evolve them into birds?

 

 

CharonY, sorry not a regular here...

[Phi for All]

Also this belongs to speculations.

Technically, while we are speculating, we're still trying to use accepted evolutionary principles to do it, so the thread could stay in the mainstream fora. However, geologically we went completely off the charts with the flood that covers all the land scenario. We'd never have enough water to do that.

 

By the way, Phi for All, you say that if we evolved wings, we'd become smaller. Does that mean that's what happen to the dinosaurs? It took a catastrophic event to evolve them into birds?

I said flyers tend to be lighter weight-wise, with hollow bones and muscles meant mainly for flight. And with your flood scenario, I meant that you removed much of our diet when you removed the land, so we'd most likely tend towards smaller bodies requiring less food to survive. Of course, being omnivores, we'd get hit pretty hard trying to live only on what we could find in the oceans.

 

There were birdlike creatures among the dinosaurs. Dinosaurs and birds share a lot of physiology and behavior. Catastrophic events tend to change environments and cause some marked evolutionary changes, but I don't necessarily think a catastrophe was required in order to force the changes into the birds we see today.

[questionposter]

There isn't really a lot of science to support "if" human had wings, because having such things would be incredibly inefficient. You'd have all these weird extra-muscles attached to your rear delta muscles that you'd need to somehow have room for and they would weigh you down in the back and take more energy to keep alive, and you already burns more than half a pound of day from metabolism without any extra movement at all. Maybe if people had wings instead of arms...it would make more sense.

But anyway, in order to get to that point it will take many small steps as it did with dinosaurs, so it would likely take much longer than 100,000 years.

Edited April 25, 2012 by questionposter

[Phi for All]

Maybe if people had wings instead of arms...it would make more sense.

I agree, in terms of existing physiology. But where would the selective pressure come from in our present ecosystems?

 

Losing our arms would be horrible for humans unless we could keep hands at the ends of them, and then I'm not sure the wing parts would be effective. Being able to fly is no real advantage to advanced tool users.

[md65536]

And probably my most important question, how long (years) would it take for them to evolve those wings, if the process started now? 100,000? 200,000 years?

Evolution isn't pre-designed. It's not like there would be a end-product wing design that would slowly evolve over that long. If it "started now", what would keep it going, to make each iteration more wing-like? What would make the iterative steps---the partial wings---into significant evolutionary advantages? It could be done artificially of course... are you considering that option or are you talking about evolution through natural selection?

 

Here's an example scenario:

Suppose in the future we've built massive skyscrapers that last essentially forever, but that mankind has "fallen" and is essentially dumb and primitive. Suppose we all live high in these buildings, the only place where there's enough sunlight to survive on. Suppose the windows have all fallen out and there's a significant danger of dying from falling out of buildings, so much so that it becomes a deciding factor in our survival (which is really unlikely because food and water scarcity would likely make "deaths due to falling" negligible). But suppose lots of us fall out of buildings and many survive, maybe due to some combination of body composition, weight, body surface area, etc. So those able to survive falling have some major evolutionary advantage. The "surface area" might involve more skin, loose skin, and long or rigid body hair. It assumes we've stopped wearing clothes which would negate any natural adaptations. Perhaps we'd evolve a type of "parachute" ability to slow our descents. Along with other adaptations we might evolve an ability to jump between buildings, which would be a huge competitive advantage. --- This by the way mimics the way wings may have evolved in the past, where surviving falling out of trees and jumping between them were useful abilities... But I don't see humans doing this with trees in the future, and dying from it enough to naturally evolve a survival mechanism.

 

So perhaps humans evolve huge webbed skin between arms and bodies, and become lighter, and grow hair that becomes feather-like, and eventually develop hang-glider-like abilities. With perfect conditions (harsh conditions that really favor anything wing-like but not harsh enough to hinder survival of the species)... I really have no idea but I'd guess a few hundred or thousand generations (which might evolve to be shorter in between, with the right conditions) might do it.

 

I think this scenario is completely improbable and even with "perfect" conditions, I'd expect to see any number of other unknown adaptations occurring before functional wings happen.

 

Without nigh-perfect conditions I wouldn't expect any wing-like adaptation to evolve into anything functional on something much like today's human in today's environment... not in billions of years. I just don't think any partial mutation would provide a significant evolutionary advantage enough to be selected.

 

Another scenario is if anything wing-like becomes socially/sexually desirable, which could evolve decorative (peacock tail style) wings.

 

 

Edited April 25, 2012 by md65536

[questionposter]

I agree, in terms of existing physiology. But where would the selective pressure come from in our present ecosystems?

 

Losing our arms would be horrible for humans unless we could keep hands at the ends of them, and then I'm not sure the wing parts would be effective. Being able to fly is no real advantage to advanced tool users.

 

Well maybe if people had hands on the ends of their arms like pterodactyls. There wouldn't really be much selective pressure, any genes that might help with starting it would just form an equalibrium throughout the population, but maybe if there was an apocalypse it might help.

[Jonathanaronda]

@md65536: I was only talking about Natural Selection, no artificial options. Loved your response though, thanks.

 

Would love to read from more people, this is interesting.