Thread: Origin and Evolution of Birds

I wanted to start a discussion on the origin of avian flight. Many evolutionary biologist assert that modern birds are descendants of theropod dinosaurs. So what do you think? Are birds modern day dinosaurs?

I would appreciate a scientific argument without reference to the "word of God"...this is not a discussion of creation.

Well they didnt start to fly right away, so what was the need for them to develope wings, feathers, and light bones? I would say their ancestors were probably involded in some sort of long jumping drive.

Maybe jumping from tree to tree like flying squirrels. Wings could have been primative gliders. Feathers could have been used to slow the rate of decent and keep the body warm. Light bones could have also been for slow rate of decent, but would also have been more likely to break have there been a bad landing. So if they were tree jumpers, I doubt they would have developed light bones right away.

Some of the scientist say that Archaeopteryx may have been the ancestor. It could have jumped at its prey while using it's bottom claws to attack. THe wings could have been used to move directions in the air for a pin point attack. Bones would help the airborne movement, and no fear of breaking them from a long fall. Feathers used for warmth, but I'm not sure how much they helped in the jumping attack.

Are birds dinosaurs? If I were to guess, I'd say yes.

what about flying insects?
maybe they grew animal bodies because they ate more protein and mated with the duck billed plattipus. but the penguin got screwed. and how about the ostrich?

yes, there are left overs from the dinosaur age. aligators and cockroaches. evolution is fucking cool.

Originally Posted by sectionOne

what about flying insects?

I would think that would have been a different evolutionary branch. A insect evolving away from the exoskeletion seems like a hard task.

Originally Posted by sectionOne

yes, there are left overs from the dinosaur age. aligators and cockroaches. evolution is fucking cool.

Cockroaches? I didn't know that.

"Maybe jumping from tree to tree like flying squirrels. Wings could have been primative gliders. Feathers could have been used to slow the rate of decent and keep the body warm. Light bones could have also been for slow rate of decent, but would also have been more likely to break have there been a bad landing. So if they were tree jumpers, I doubt they would have developed light bones right away." -TenGig


I would say that dinosaurs were birds as well.

That explaination is certainly a reasonable one. I find the research of Dr. Kenneth Dial particularly intriguing, however. He suggests that the evolutionary advantage of incipient wings on feathered theropod dinosaurs was the improved ability to ascend steep inclines by creating an acceleration toward the incline by flapping their feather covered fore limbs

Dial, Kenneth. "Wing-assisted Incline running and the evolution of flight." Science 299(2003):

Originally Posted by SciGuy

That explaination is certainly a reasonable one. I find the research of Dr. Kenneth Dial particularly intriguing, however. He suggests that the evolutionary advantage of incipient wings on feathered theropod dinosaurs was the improved ability to ascend steep inclines by creating an acceleration toward the incline by flapping their feather covered fore limbs

Dial, Kenneth. "Wing-assisted Incline running and the evolution of flight." Science 299(2003):

Well I haven't heard that one before, interesting idea tho. Even found a video showing of a duck doing it

YouTube - Wing assisted incline running and evolution of flight

But I'm not totally convinced yet. Or at least this was not the main reason for developing wings.

Before they had wings they could only climb up small inclines. Was there that great of a need to be able to climb a incline of 11 degrees compared to 10 degrees? For the energy spent, I would assume there would be something better to evolve to.

It may help explain how they were able to get up the trees to be able to jump or glide. I dont think that there is any doubt that wing surface area presents an increased ability to run up steep or vertical inclines, but whether or not it is was the primary reason for the evolution of wings I am not sure.

This is actually an interesting thread I can add little to.

As far as what makes the most sense of the examples here is based on the work K. Dial.

Originally Posted by SciGuy

It may help explain how they were able to get up the trees to be able to jump or glide. I dont think that there is any doubt that wing surface area presents an increased ability to run up steep or vertical inclines, but whether or not it is was the primary reason for the evolution of wings I am not sure.

ok, but how about this... let's say gravity was less during the time of dinosaurs, because their weight couldn't possibly have been sustained with the current earth gravity. so when the big meteor shower hit the planet and made them extinct it also knocked out moon a few degrees off so it changed the pull. well then creatures were heavier and those who had to escape the ground from predators had to develop wings as a defense mechanism?
pass the bong.

why couldn't their weight have been sustained with the earth's current gravity? I can find no evidence of such. And how could a meteor show have altered gravitational pull on earth enough to change the sizes of the organisms on it?