The Origin of Flight--What Use is Half a Wing? | HHMI BioInteractive Video

Share this video on

What's Hot

What's New

Top Grossing

Top of the Chart


Talk Beliefs : Absolutely fascinating and great work. Beautiful animation by Stated Clearly.

Dorothy Menefee : I've seen my chickens do these kind of things. Its a bit surprising how high up into trees and on top of buildings they can get if they want to. They technically can't fly but they use their wings to assist in jumping and running up steep slopes to get where they want to go.

Jason Heartthe4rth : That falcon at the end is absolutely amazed about this video.

Derek Bryceson : Protection - Display - wall climbing - parachute - hanglider - flight. That's the simplified version of feather evolution.

mikebe41 : and thus...the origins of spicey buffalo wings

Alyenbird : You could also look at modern flightless, and almost-flightless birds for clues. Many flightless birds, such as Ostriches, Rheas and Kagus use their wings for display - both to scare off threats, and to attract mates. The Kagus' highly patterned wings are the most colorful part of their otherwise drab grey bodies. These species also use their wings to cover their eggs during incubation. Tree-climbing Kakapo and Hoatzin chicks use their wings for clambering around and keeping their balance in densely forested habitat. Adult Hoatzin and Kokako are both very very poor fliers. They mostly jump or climb to get around. If they have to cross a large gap though, they will glide.

Matt Evans : birds are still a type of theropod dinosaur

Kknown Unkknown : 4:01 should be a meme

Bamba Zillah : amazing work!

Nathan Lang : Wow, a very insightful video. I feel like i learned something every minute of it.

poppedweasel : Considering the small size of Archeopteryx, the progenitor of birds were likely small and arborial. Not like the Deinonychus shown running at the beginning of the video and implied in the narration. Sugar gliders and flying squirrels are a good example of how a non flying animal can evolve into a flying one. Early therapod fliers had not yet developed the breast bone and flight muscles to perform the ways shown in these examples. Using a grouse that already has these developments sours the experiment. It makes far more sense that wings first evolved as a gliding instrument and evolved to flap with stronger and stronger beats as the mechanics and biology of flight was honed over time.

A FUCKING WHITE MALE : The tree down/glider hypothesis seems a lot more plausible. We see it in tree-living mammals, and we have found winged dinosaurs that were gliders.

insect illuminati Get shrekt : Insects where flying long before dinosaurs where even a thing

Peeble Kitty : Here I go, into the comments, bracing myself for complaints of "pigeon abuse"

Ewan Flean : Hasn't the guy that asked Darwin that question seen a chicken? They can't fly, so what's with the wings?

BertyFromDK : In other words, the birds sort of fly INTO the tree trunk, thereby increasing the traction of their feet.

mrnickbig1 : Ground up is a very stupid idea. Early birds clearly evolved from small gliding arboreal dinosaurs. Many features of maniraptors CLEARLY are adaptions for climbing. The long clawed hands, the ability to splay the legs, the terrible claw on the inside of the foot, the very flexible neck, which allowed a high degree of head rotation, et cetera, are all examples that are still found on contemporary climbing animals, like squirrels.

zegh8578 : Wing feathers have been used by theropods to cover nests and hatchlings, protecting them from the environment. Focusing too hard on the flight-aspect is risky, because it forces evolution to become "goal oriented". Dinosaurs didn't evolve wings "so that one day they might fly", but for reasons relevant there and then: Insulation, protection, display, covering

Rye Bread : Weight is not taken into consideration with this, or muscle structure for that matter. Try this with actual flightless birds with feathers.

Scott K : YEEEESSSSSS!!!!! I've been wanting to know the answer to this for years. Thank you. Bravo.

Mark L : Astounding work! I'm subscribing

IcarusCAE : I knew Walter White didn't die!!

Garett Miller : Clever scientist

DavidCO : In nature it's often survival of the luckiest, not the fittest.

Vutipong Chaichanapunphon : Yeah and how dragonfly has a wing?

Danijela Ivezić : only 781 likes?

Rashid Hatim Parker : Like a giant chicken,yeah sure u can’t fly,but at least u can jump up to some places with the boost also from the small wings unlike most creatures

KINGDOM : I guess Ostriches and Penguins are still evolving.

Raptor Jesus : i'm disappointed with the lack of entertaining religious comments, where you at creationists? i need a laugh! XD

Michael S : Science will always find the answer to the irreducible complexity argument. Richard Dawkins gives a lecture in early 90's that demonstrates how "half a wing" could be beneficial in tree species by slowing down an animal upon falling. He used xmas ornaments and a paper "wing"

c.sagan : Thanks for this show

Z A N E : irreducible complexity by its very definition is a failure to understand the simple fact that before it was used for flight it was used for something else. like duh.

Jack Baylis : so, basically, as theropods became smaller in order to survive, they used their "half-wings" as a way to escape predators?

Marvin M. : so instead of lifting them in the air, the wings are used like spoilers in a car, creating downforce and therefore more grip :D

Ghost Gutarist : Evolution is a myth, Noah gave birth to dinos actually.

Fennecfoxfanatic : This was a good video! Subbed!

Chingiz Zhylkybayev : "How flight evolved" - you mean how flight in birds evolved. Insects had been flying for hundreds of millions of years by then.

François Cauneau : It's a small step for a chick, but a great step for the humankind. Thanks for sharing with us this important moment in Science !

Sir Meow The Library Cat : 😳 The subtitle of this video is somewhat disingenuous. There never was ‘half’ a wing! Or ‘half’ a leg! Or ‘half’ of any anatomical element in a creature. Professor Dial does use correct terminology when speaking of ‘smaller ‘ and ‘larger’ wings changing size incrementally through time. That said, this is a fascinating account of his research and the involvement of his son! Well done, both of you! PS. Aren’t birds extremely fascinating?

skl : facinating

andreisabe : The beauty of evolution. Great video!

Dávid József Ferenczi : I still don't get it ... an animal trying to reach higher areas (getting a bugs or escaping predators), why is evolution focusing on turning their claws/arms/finns into wings instead of boosting their Jumping muscles? Every creature that can fly, starts with a jump... unevolved creatures without wings, are jumping a lot. Why not evolving into a Kangoroo-like creature instead of their arms transforming into wings? Imagine humans catching butterflies for generations : jumping around flapping their arms. I'm pretty sure we would have ultimate leg muscles after many generations and evolving instead of getting wings.

haytham Messaoudi : +Lindsey Esparza the avian dinosaurs probably became smaller to escape the kt extinction also a larger animal would have to use more energy to flap/fly

A Shore : Fascinating... but on the vertical test, the quail is clearly not SOLEY using its wings to push itself on the log for grip. It's also flying to some degree, but does still present a strong argument for why half-wings are advantageous to none at all.

Andreas Söderberg : Really interesting!

colin Paterson : A very interesting study.

Tens Flavo : There's always those handful of guys who come to videos like this and start preaching about their god of the gaps.

MrOhWhatTheHeck : But even this requires a fairly highly developed set of wings. Unless you believe that these 'half-wings' were evolved in a single mutation, the question still hasn't been answered.

Stan Gable : Extremely insightful video

Kaiser Frost : I admit when I first heard of this hypothesis it sounded far-fetched but then nature is always doing unexpected things! Fossil evidence seems to confirm it. We go from fluffy downy dinosaurs to dinosaurs with "wings" quite suddenly. Why on earth did velociraptor have wings and tail feathers? Well for display partly, but mostly to get up trees that bigger predators couldn't climb! At that point theropods and most other dinosaurs probably already had air-sacs and chambered lungs so it was only a short jump to powered flight. God I love bird evolution! The things birds do are so taken for granted.