Did all birds evolve from just one species of flying dinosaur? Or did multiple dinosaur species converge on the feathers design?

Another way of saying that is, do all modern birds have a common ansestor about 65 million years ago?

It appears that they agree that birds have a common ancestor, but it is unknown...

http://www.eurekalert.org/pub_releas...DSF-151196.php

It was once thought to be the Archaeopteryx, but the link provides evidence against this.

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Given that birds are relatively closely related I'd guess they are monophyletic, that is to say they have a defining common ancestor species. That ancestor species was presumably either a bird, a dinosaur, or an intermediate form; in any case the immediate or ultimate dinosaur ancestor was a single species. As for 65 million years ago, I'd guess somewhat earlier.

All guesses - anyone know more?

Evolution within species is proven ...

The uniqueness and diversity of species has not been proven to be the result of evolution ... it's a mystery ....

An even greater mystery ... how does a rock become conscious?

It's not a mystery at all. It's settled. You should start a thread in Against the Mainstream. There are lots of people who would be happy to explain it to you.

No rocks have ever become conscious. 99.9% of living things aren't even conscious.

By their own admittance ...

“What Darwin did in his revolutionary treatise, “On the Origin of Species,” was to explain how much of the extraordinary variety of biological traits possessed by plants and animals arises from a single process, natural selection. Since then a large number of studies and observations have supported and extended his original work. However, linking natural selection to the origin of the 30 to 100 million different species estimated to inhabit the earth, has proven considerably more elusive.

In the last 20 years, studies of a number of specific species have demonstrated that natural selection can cause sub-populations to adapt to new environments in ways that reduce their ability to interbreed, an essential first step in the formation of a new species. However, biologists have not known whether these cases represent special exceptions or illustrate a general rule.”

From .... www.physorg.com

Rocks .... isn't that how the universe started? As minerals ..
Okay ... a soup of ionic matter and radiation then ... that's even more impressive ... How does that become conscious?

Unless it was already potentially there in the singularity ....

You don't have to answer ... I don't want to derail the thread ... just something to think about.

liar.

post it in Against the Mainstream or go here:
http://groups.google.com/group/talk.origins

Yes, monophyletic. Perhaps related most closely to the Dromaeosauridae, a bunch of bipedal carnivorous theropod dinosaurs.
Whether the ancestor was actually a flying dinosaur is something I think hasn't been decided yet. There are already examples of flightless but feathered theropods from the late Jurassic / early Cretaceous: Protarchaeopteryx robusta and Caudipteryx zoui. If we chose feathers as a synapomorphy (defining feature) of Class Aves, then we'd have to say that birds evolved from some flightless, unfeathered ancestor of Protarchaeopteryx and Caudipteryx. But we might insist on more birdlike features, in which case the ancestor might be a leaping, gliding or flapping feathered creature, perhaps descended from Protarchaeopteryx or Caudipteryx, or some feathered relative of theirs. But I think no-one has decided on where the line should be drawn between bird and non-bird, given the sparseness of the fossil record.

Grant Hutchison

In one of Richard Ellis's books, he quotes a paleontologist as saying that one will probably never any real ancestor to another species in the fossil record; the odds are just stacked against it. That said, he also admits the fact that similarities between different species can be used to establish general evolutionary trends.

Anyways...carry on.

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Yeah, there's going to be a dotted line drawn somewhere saying: above this line we agree it's nothing but birds. From the earliest fossils agreed to be above the line, and the latest fossils agreed to be below the line, we'll be able to make some more-or-less detailed statements about what sort of creature gave rise to the bird lineage, as we have defined it. But that's about as much as is likely to happen, if I understand the process correctly.

Grant Hutchison

Frustratingly, there was misinformation on this subject on The Food Network, of all places, last night. They were talking about eggs on . . . oh, I can't remember the name of the show, but it ends in an ellipsis, which the host tediously refers to as "dot dot dot." Anyway, he was going on about how there was no proof of which came first, the chicken or the egg. I then went on at my poor boyfriend for quite some time about the fuzzy nature of species boundaries.

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Gillian

"Now everyone was giving her that kind of look UFOlogists get when they suddenly say, 'Hey, if you shade your eyes you can see it is just a flock of geese after all.'"

"You can't erase icing."

"I can't believe it doesn't work! I found it on the internet, man!"

The mainstream scientific view is perfectly represented in the quote ...

"However, linking natural selection to the origin of the 30 to 100 million different species estimated to inhabit the earth, has proven considerably more elusive."

As I said ... Evolution within species has been proven without a doubt ...Humans are a perfect example ..

Other aspects of how the process of evolution works have not been proven without a doubt so I don't think it is "settled" at all ...

There are certain views that have settled into concrete though ....

Are you aware that we have seen new species come into existence?

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"Arrrgh, the laws of physics be a harsh mistress!" -- Bender

Indeed. Eric12407, you're both distinctly off topic and ATM, as well as undermining your original contention that:Grant Hutchison

Well, see, here's your problem. Science doesn't work that way. After all, some people will doubt anything, no matter how much evidence it has (like, oh, evolution) just to be contrary.

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Gillian

"Now everyone was giving her that kind of look UFOlogists get when they suddenly say, 'Hey, if you shade your eyes you can see it is just a flock of geese after all.'"

"You can't erase icing."

"I can't believe it doesn't work! I found it on the internet, man!"

If all the birds come from one common line of decent then how come some are herbervores and some are birds of prey?

Assuming the evolutionary scenario the would require more than one line of decent and yet they so similar.

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Many are omnivores, too. A bit of subspecialization either way is all that's required. Couldn't that all happen within Class Aves, as an adjustment to the carnivorous habits of the ancestral theropod? Lots of vacant dietary niches to fill once you start flying!

Grant Hutchison

Sometimes people are so tied to a particular view they can't even see what you have written ...

I have no problem with evolution ...

I believe in evolution ...

I believe the whole universe is "evolving" .... every aspect of it ... including our minds ...

I do not believe that how this "process" of evolution works has been totally explained without a doubt ... and neither do mainstream scientists ...

No, but neither has gravity, or atomic theory, or anything else, because science doesn't work that way. Science doesn't ask for proof. That's for mathematicians.

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Gillian

"Now everyone was giving her that kind of look UFOlogists get when they suddenly say, 'Hey, if you shade your eyes you can see it is just a flock of geese after all.'"

"You can't erase icing."

"I can't believe it doesn't work! I found it on the internet, man!"

and how science would counter this stateent...

I grasp the theorey of evolution.

I understand the facts in evolution are sufficient to warrant the hypothesis' elevation to a theorey.

I understand the limitations and usage of words and try not to misuse terms to convey an emotional bias... i hesitate to engage in unnecessary hyperbole... including watered-down 'feel good' phrases.

I understand the process through which evolution takes place and where my understanding is lacking, i seek out cogent arguments backed by fact to further broaden my grasp of the topic... and I appreciate the work science has done to come to this conclusion.

That, to quote a green muppet, is why you fail.

john

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You can find it all in The Tree of Life website.Saurischians (from the Greek Saurischia meaning "lizard hip") are one of the two orders/branches of dinosaurs.
And from The Tree of Life site you link to Answers.com page on birds and you get to: So the answer is they all came from one line of dinosaur though some of their structures evolved more than once and occur in other species.

This is a consensus but I believe some gray areas may still exist.

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Indeed.

I was wondering why Sticks was so convinced that creatures that eat different types of food cannot share a common ancestor.

I suspect it is because Sticks does not understand evolution, historical geology, paleontology or biology. This would seem to be confirmed by previous posts made by Sticks.

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"I'm as accurate as any psychic. And I'm a cartoon!" -- Squidward

"Arrrgh, the laws of physics be a harsh mistress!" -- Bender

I think you're right about Sticks, but he deserves credit for making an honest effort to understand. There's hope for him.

Sticks, in answer to your question, there are many examples of carnivorous animals with herbivorous ancestors, and vice versa (for example, all dinosaurs, including the plant-eaters, are descended from a carnivorous group). This is not a problem at all for evolution.

So did the dinosaur decide he wanted to fly and just started to grow feathers or did the feathers come first and then he decided .. hey!.... maybe I'll try flying with these things ... oh wait a minute ... I have to grow some wings too.

I guess the first one to try jumping out of a tree or off a cliff was successful .. otherwise they would have given up wouldn't they? Or maybe they just waited around for a few million years until they were perfectly capable of flight just to be sure ...

Perfectly capable of flight, like the ostrich, the pinguin, the dodo, ... ?

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Here is a list from Talk Origins on a number of fossils that share reptile and bird characteristics.

We cannot assume that feathers evolved purely to allow flight. As Fram pointed out there are many species that have feathers and don't fly, or fly poorly (chickens). Feathers could have evolved for other reasons from the original ancient species (warmth, sexual selection pressures, repel water, .etc) so it is a massive simplification that an animal suddenly developed feathers then tried to fly with them.

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Feathers seem to have come first. There have been several discoveries of theropod dinosaurs with feathers and no flying ability at all. As TriangleMan pointed out, feathers have a lot of uses, and it's hard to determine which one(s) drove their evolution.

Your question touches on a very important point which is often misunderstood (sometimes, I think, deliberately): organisms do not "decide" to evolve. That's not the way natural selection works. For whatever reason, proto-birds which were better at getting off the ground had a survival advantage over those which were worse: these genes thus became more prevalent in the population, which over time evolved into a species capable of full flight.

A dinosaur didn't wake up one day and decide to grow herself a pair of wings, just as you-as-a-fertilised-egg didn't decide to grow arms, legs and a head. There's nothing conscious about it. Just genes, environment and time.

This is pathetic, weary old stuff. Are you really unaware of the large amount of theory and data that undermine this straw man? Or do you just think we might be unaware of it?

Grant Hutchison

That's what I think too of course ... I think there is a force required to drive an organism towards ever greater degrees of complexity ...ultimately resulting in the most complex organism we know of .. humans

It might be some kind of force as yet unknown or unrecognized or beyond measurement with our present capabilities ...

How about------------ evolution!?!

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