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.

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

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.

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.

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

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

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

Dovahsaurus PaleoKnight : Simply extraordinary and mind blowing!

Mexican cartel ! : I'm gonna show this to my dad because my dad was convinced that God created everything and evolution is a hoax he doesn't understand how wings evolved for eyes or complicated organs

Kknown Unkknown : 4:01 should be a meme

BFDT : in nature, it's the survival long enough to successfully reproduce that counts. Not, the fittEST, just fit enough.

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

thegreeenbeast : I actually made a similar observation in the game Spore. In that game you get to manipulate the evolution of your own species from one cell to modern civilization. Its far from perfect and it really is a game. However at a certain point you get the first stages of wings which arent particularly good af flying at all. What they ARE good at however is helping you climb almost vertical walls!

Lucas Lin : Okay but that owl flying is the cutest thing ever

Matt Evans : birds are still a type of theropod dinosaur

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

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

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.

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

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

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.

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

Aniekan Umoren : I READ THIS STORY IN THE SAT!!!!!!!!! It was so interesting, it made me waste time on it and fail the practice test lol

KINGDOM : I guess Ostriches and Penguins are still evolving.

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.

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

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.

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

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

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

Nick Gurz : So it's neotony? The baby dinosaurs were born with little wings to run up trees after generations of necessity that eventually developed into full working wings? Nice. Never considered that juvenile traits could develope to maturity!!! Nice work!

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.

sabin97 : my parents have free range chickens. they sleep up a tree. there are some hens with chicks. once the chicks start getting feathers(they have almost like hair when they hatch) the hen clibs up the tree(they all do it by flying) and the chicks try to climb with their feet and wings. but when they are still little they never quite make it to the tree, so the hen takes them elsewhere to sleep. after they grow some more they are finally able to climb, and eventually fly to the tree. always the same tree, as the sun is going down. chicken can fly a very short distance, maybe 5-8 meters vertically......and then they kinda glide's like a really high jump...assisted with wings....

Dee Elmore : vertical? you mean BIRDical *gets stabbed*

Garett Miller : Clever scientist

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

101jir : 2:29 A very good anecdote for a common phenomena in biology: listen to the farmers/ranchers/etc! They may not be scientists themselves, but they have generally spent much more of their lives around the animals in question than many scientists! That doesn't mean their theories are always correct, but much of the recent advances in animal psychology and biology can be attributed to the internet. Stuff comes up online, all conditions on record, that previously would have been scoffed at as an elaborate hoax. Animals do strange things, and what is common sense for a rancher (in this case don't start birds on the ground) is breaking news for some scientists. A good scientist gathers information not only from the scientific community, but from all those that have regular interaction with the subject in question. Don't dismiss the opinions of those that have experience but lack scientific background. Rather, consider them as sources for new ways to go about experimentation and theories to test. This, however, does work both ways, something also represented in this anecdote. Those with experience sometimes miss the point, such as when the rancher said that the data was "horrible" because the subject was "cheating." Another good anecdote is the story of the "multiplying horse." While the rancher was incorrect in thinking his horse knew how to multiply, the story did demonstrate that horses are capable of picking up on extremely subtle social cues, more subtle than most realized at the time.

Daniel Gallehugh : I love dinosaurs more now thanks yous.

Zetahoven : This makes a lot of sense. Theropods typically had very strong legs and claws and often faced predation especially cannibalism. Most trees at the time were also extremely tall and any dinosaur big enough to reach was most likely not interest in tiny meat. Perhaps because of this smaller theropods retained this escape capability and through natural selection became smaller and more adept at flight.

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

David Packer : That is the exact behavior of the Hoatzin in South America these birds retain claws on their wings for climbing and their young use the climb/glide method for defense when their parents are flying off to forage for food

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 !

andreisabe : The beauty of evolution. Great video!

Pat Doyle : Excellent work! Yet another possible, and dare I say likely, answer to the question!

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

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.

Travelers : I remember reading about your research in a GED or SAT training book. :D

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"