Well evidently they had sufficient fossils to track this miniaturization process in the branch of theropod dinosaurs they believe became birds eventually. And since the article stated that the dinosaur snout evolved into a beak over millions of years they have the fossils of these creatures with intermediates between having snouts and beaks, No? What a shame. We'll just have to take their word for it then.geo wrote:If you had actually read the article, you’d know that some dinosaurs became very small first and it was that miniaturization likely conferred an advantage. Small size was only one of several adaptations that eventually led to the bird. This is absolutely supported by the fossil record. Indeed, dwarfism has occurred throughout evolutionary history, even in humans. This is well known and not controversial. You betray your ignorance of the subject.
Sure there is dwarfism and gigantism but it's not usually the norm. It may that theropod dinosaurs did rapidly reduce in size but evolution has no foresight or goal they say.
It's not a problem that birds these dinosaurs are supposed to have evolved into appear millions of years earlier than them in the fossil record, and modern birds were flying over their heads while they were busy evolving into them?
It seemed like they were saying that snouts evolved into beaks. Fossil intermediates please? They got the miniaturization process fossils so why not these intermediate snout/beaks?geo wrote:What the article actually says is, “small changes in how genes are regulated likely drove both the initial creation of the beak, which evolved over millions of years, and the diverse shape of bird beaks, which can change over just a few generations.”
So it’s the shape of beaks that can change over just a few generations. This is evident even in Darwin’s finches. Not controversial, Flann.
Beaks are not that unusual in the animal kingdom. Beaks are present in a few invertebrates (e.g., cephalopods and some insects), some fishes and mammals, and all birds and turtles. It's not a great surprise that some dinosaurs were beaked.
Finch beaks change shapes in populations based on types of food supplies,droughts etc. What does this mean? Those with the appropriate beaks survive and interbreed accentuating that trait but this can change again depending on conditions. Or maybe that trait is expressed more frequently in response to the environment but it must exist already in the genome to be expressed.
It's not a new trait.
It's not just creationists but people like Quick and Ruben who think there are physiolgical differences in leg structures that imply theropod dinosaurs could not support the respiratory system that birds have.geo wrote:It’s funny to me that Creationists persist in digging their heels in even as as paleontologists discover more and more feathered dinosaurs that only confirm the theory that birds evolved from dinosaur. Birds share many unique skeletal features with dinosaurs and there are even very small dinosaurs, such as Microraptor and Anchiornis, that evolved arm and leg feathers and eventually wings.
Reptiles are cold blooded but birds warm blooded. They speculate again that some dinosaurs may not have been cold blooded.
You have to assume that if this was possible these theropod dinosaurs were warm blooded unlike the vast majority of reptiles.
And bats are mammals that fly yet there is not a single credible ancestor for bats and they are actually well represented in the fossil record, contrary to claims otherwise. By the way what and where are the ancestors of the dinosaurs in the fossil record?
It's a cleverly constructed theory for dinosaur to bird evolution but the crucial fossil evidence is missing. I would agree with Sagan but I'm not the one believing life constructed itself originally from chemicals, while everything we know tells us that this does not happen, but life alone generates life.geo wrote:As one of articles I previously linked discusses, a scientific theory must be refined in light of new evidence. It’s expected and necessary. Bird evolution is a fascinating area of science, an unfolding mystery. It’s too bad Creationists are too entrenched in their religious ideology to be able to see the wonders and mysteries of the natural world. As Sagan once said, “it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.”
For convenience here are the top ten "nitpicks" http://www.discovery.org/a/24041
I'll leave at that.