Vanes in the primary flight feathers of Archaeopteryx conform to the asymmetric pattern in modern flying birds…evidence from flight in Archaeopteryx has been available for more than 100 years…Ostriches (Struthio) and rheas (Rhea and Pterocnemia) are flightless and are thought to have evolved from flying birds…the basic pattern and proportions of the modern avian wing were present in Archaeopteryx and have remained essentially unchanged for approximately 150 million years…
The Late Jurassic Archaeopteryx has been thought to have been a feathered predator adapted to running that represents a terrestrial stage in the evolution of true birds from coelurosaurian dinosaurs. Examination of claw geometry, however, shows that (i) modern ground- and tree-dwelling birds can be distinguished on the basis of claw curvature, in that greater claw arcs characterize tree-dwellers and trunk-dwellers, and (ii) the claws of the pes (hind foot) and manus (front hand) of Archaeopteryx exhibit degrees of curvature typical of perching and trunk-climbing birds, respectively. On this basis, Archaeopteryx appears to have been a perching bird, not a cursorial predator…Two major theories for the evolution of avian flight—the cursorial theory, in which flight evolved from the ground up, and the arboreal theory, in which flight evolved from the trees down—are based on interpretations of the paleobiology and behavior of this primal bird…To determine if the geometry of the claws of the pes is a useful index for arboreal versus terrestrial habits in birds, I examined more than 500 species of birds, photographed approximately 400 claws (digit III), and traced and measured the claw arcs…The major separation of birds on the basis of claw arc measurements is between ground-dwellers and all others…[Archaeopteryx ] had the feathers of modern birds, unchanged in structural detail over 150 million years of evolution…exhibited the classic elliptical wing of modern woodland birds…exhibited a hypertrophied furcula (fused clavicles)…which effect the downstroke of the wing…Its tail was designed to provide lift in flight and was not loosely constructed; not did it show signs of fraying, which is characteristic of terrestrial birds…Archaeopteryx was arboreal arvolant, considerably advanced aerodynamically, and probably capable of flapping powered flight to at least some degree. Archaeopteryx probably cannot tell us much about the early origins of feathers and flight in true protobirds because Archaeopteryx was, in the modern sense, a bird…
Since the first Archaeopteryx specimen was discovered in Germany in 1861, scientists have been pecking at each other like bantam roosters in an attempt to sort out the creature’s true place in evolution. The latest phase of the controversy pits ornithologists, who consider the 150 million-year-old creature a bird, adapted to life in the trees and capable of powered flight, against paleontologists, who claim Archaeopteryx was a dinosaur that spent most of its life on the ground…Alan Feduccia of the University of North Carolina at Chapel Hill argues that the claws of Archaeopteryx indicate that it did live in the trees and was unquestionably a bird. ‘Paleontologists have tried to turn Archaeopteryx into an earth-bound, feathered dinosaur,’ Feduccia says. ‘But it’s not. It is a bird, a perching bird. And no amount of ‘paleobabble’ is going to change that’”…[Following upon Henry Huxley’s position (in the late 1860s) that birds are descended from dinosaurs, in 1973 Yale University paleontologist John Ostrom wrote to Nature and] “asserted that the skeleton of Archaeopteryx was ‘that of a coelurosaurian dinosaur…Since Archaeopteryx apparently lacked breastbones for anchoring flight muscles, he questioned whether it could fly at all and suggested that its claws resembled not those of high fliers but the feet of lowly ground dwellers such as quail and roadrunners”…if Archaeopteryx ran on the ground, then avian flight probably originated when creatures like Archaeopteryx began leaping up (after insects, say) rather than swooping down from the treetops…now even paleontologists concede Archaeopteryx was capable of flight. ‘Okay, in the vernacular sense, it is a bird,’ grouses Jacques Gauthier, a herpetologist at the California Academy of Sciences in San Francisco and a supporter of Archaeopteryx’s dinosaur ancestry. ‘If by that you mean something with feathers that sort of flies’…its claws resemble those of birds that spend most of their time in the trees. To substantiate his claim, Feduccia measured the curvature of the foot claws (Archaeopteryx also had claws on its wings) of the three best Archaeopteryx specimens, then compared this arc with 500 species of modern birds. The fossil’s arc fell comfortably in the range of definitive perching birds…the fossils’ curved claw on the reversed first toe…is ‘strictly a perching adaptation; it would be a tremendous obstacle to running on the ground’…‘The claws are extremely similar’ to the foot claws of modern trunk-climbing birds, he [Feduccia] insists. ‘In fact, if you compare the claws of a wood creeper with the manus claws of Archaeopteryx, you would be hard pressed to tell them apart. They are virtually identical’…
"A little birdie told me that some atheists claim that science has found a transitional form from reptile to bird..."Actually, people found it. True story. It's got cousins, too. And other feathered dinobirds have been found recently, too, including some digs that have shown that some of the dinosaurs we thought were bald either had feathers or had feathers when they were wee theropods. Adorable!"...and that this, somehow, has something to do with God’s non-existence."Only the gods that claim to have done things in a way different than the evidence says (like that one that claims to have done things in the wrong order in a severely compressed timespan, with no semblance of common descent for the wee beasties, etc*). So...all of them so far, as far as I'm aware. Who knows, maybe the next Revelation will get it right? I'm not holding my breath.* Which could still be correct if it's interpreted properly. That's where the magic is. Of course, every other god is real then, too.
Hello. I want to give a "thumbs up" for Modusoperandi's comments which I agree with.Evolution by bloody natural selection is an extremely strong scientific fact. The religious implications are obvious. In my opinion Darwin killed the god invention, and I say good riddance.
I'm not aware of any scientists who say that transitional evolutionary forms disprove the existence of God. I am, however aware of many, many theists who claim that a lack of transitional forms is evidence for Creationism / Intelligent Design.All the scientists are doing is exposing the claim that there are no transitional forms as the bare-faced lie that it is.
Science need make no comment on the theistic "god" fiction. The debate is among human beings. Humans conducting authentic science, i.e., fidelity to accurate observation and consistently logical reasoning, need only show that the claims of those who consider themselves "theists" or believers in their "god" fiction" are the product of grossly inaccurate observation and poor and inconsistent reasoning.Scientists need only point out proper observation and proper reasoning to those who appear dysfunctional in both.
Modusoperandi;Wikipedia, PBS and MNSBC, not exactly, who do you say, impressive scientific credentials.My favorite was Gigantoraptor since the fossil shows no clear signs as to whether it was feathered but that’s ok, you can hire an artist to paint evidence for you.aDios,Mariano
"Wikipedia, PBS and MNSBC, not exactly, who do you say, impressive scientific credentials."Would you prefer Conservapedia, Fox News and Worldnetdaily? They're what topped a cursory googling. Blame google."My favorite was Gigantoraptor since the fossil shows no clear signs as to whether it was feathered but that’s ok, you can hire an artist to paint evidence for you.""It's close relationship to other feathered dinosaurs hints that it would also have been feathered, if only on its arms and tail." (fm Cosmos)It's not slam-dunk, obviously.
In addition to what the others have said here already, I'd like to ask Mariano this: what does it prove, that people disagree about whether Archaeopteryx should be called a "bird" or a "dinosaur"? What it shows is that people like categorizing things, and when there is no obvious line to be drawn between categories, because there are steps in between, then they fight about the names. This comes up again and again in debates with evolution deniers, who insist, for instance, that there is a meaningful line to be drawn between "man" and "animal", when the fossil record shows a gradual change from, say, Homo habilis to Homo sapiens. When did we get souls?The point is, at some point, we must realize that our naming conventions are just that: conventions. They don't necessarily constrain what happens, or what has happened, in the real world, but are just more or less handy handles we use to talk about things, and when they collide (as in the case of Archaeopteryx being either a "dinosaur" or a "bird"), then we should just arbitrarily draw a line, or make up a new name, remember that it's arbitrary, and move on.Evolution is a continuum, even if we don't have a good record of all the steps. Mariano: if you want to check out a lineage where naming conventions are particularly arbitrary, look at the synapsids, popularly called the "mammal-like reptiles". If Wikipedia is too folksy for you, I can get some more scientific stuff, but it's heavy going; and I somehow doubt that Conservapedia deals with synapsids.Here the record of a major transition is very well preserved, so that it's obviously just a matter of arbitrary convention to draw the line between mammals and reptiles. Take a look.
Modusoperandi and Zilch;I do not blame google, I blame cursory googling.You can see that I provided info strictly from peer reviewed science journals that I read by physically going to my local science and engineering library.Believe me, I am empathetic to the spoiling convenience of the internet.Just type in a search for, “Archaeopteryx and God does not exist” :o) or something and hyperlink the first thing that appears, or the first with which you agree.Certainly, it is not a slam dunk since the fossil shows no clear signs as to whether it was feathered.Why not paint a picture and build a model without feathers so that it actually represents the actual evidence instead of manipulating the evidence in order to fit the theory?It just strikes me as a bit arbitrary: atheists who put up a respectability claim to appeal to the cannons of the journals but then when they want to evidence something Wikipedia, PBS and MNSBC are just fine.Moreover, and more importantly, I find quite often that the moment a scientific façaded atheist finishes telling me that science hath saith, I can check the journals and find an opposing scientifically respectable view. Just seems a bit cherry pickerish, no? aDios,Mariano
Mariano: you say-Certainly, it is not a slam dunk since the fossil shows no clear signs as to whether it was feathered.Why not paint a picture and build a model without feathers so that it actually represents the actual evidence instead of manipulating the evidence in order to fit the theory?Which fossil are you talking about here, Mariano? Take a look at the type fossil of Archaeopteryx, and tell me what you see. If those aren't feathers, I'm a monkey's uncle. Microscopic examination puts it beyond doubt.Yes, you are right: Archaeopteryx does not disprove God. As M.O. said, all it does is show that one particular flavor of belief is mistaken. It's quite possible to be a Christian and believe in evolution too. But the existence of Archaeopteryx, and countless other fossils, and lots of other evidence too, shows beyond a reasonable doubt that the Old Testament story of "special creation" is a fable.And I must confess, that I'm still uncertain what you were trying to show with your citations from the peer-reviewed literature. While there are still disagreements, for instance about classification as I said above, and also the classical "from the ground up or from the trees down" debate (which was already going on when I studied this stuff almost forty years ago), none of these people have cast any doubt whatsoever on the basic status of Archaeopteryx: that of a transitional form between reptiles and birds, which is a beautiful example of evolution.cheers from cool Vienna, zilchBtw- I don't know if I've mentioned this here, but I will probably be taking a trip across the States in June, with my charming and intelligent daughter Rosalind, starting in Pennsylvania and ending up in California. I'd love to meet any of you who live somewhere en route. Drop me a line if you feel like it, and lunch is on me.
Zilch;The reference to no clear signs of feathers was to Gigantoraptor (my later generic reference was due to me having specifically mention it in my first comment).Sorry, but I do not see how a birds such as Archaeopteryx shows beyond a reasonable doubt that the Old Testament story of special creation is a fable.I am afraid that you are completely misreading my post. This is not about taxonomy or nomenclature: “Archaeopteryx probably cannot tell us much about the early origins of feathers and flight in true protobirds because Archaeopteryx was, in the modern sense, a bird.”Btw- I would love to lunch with you during your trip. When you are ready to embark, drop me an email.aDios,Mariano
Mariano: almuerzo contigo sería un placer. Pero yo pago. Where are you?