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Racing Dinosaurs with Spoilers
PhilHibbs writes "The BBC is reporting a new theory - dinosaurs flapped their proto-wings to generate downforce for added traction when running up-hill. Another one to add to the many theories of the evolution of flight."
One proposal I've heard for the origins of insect wings is as heat collectors. What with all that surface area and the network of veins going through them, insect wings would make good solar collectors. That is, up until the wings got too big, and the heat dissipated before it could get back to the insect's body. But a study showed that just about the time they got too big to work as solar collectors, they'd be big enough to help with gliding.
It's an interesting theory, but I doubt a similar course could apply to birds. Their wings are covered with feathers, which are mostly just dead skin, and probably wouldn't absorb heat well. Plus birds are warm-blooded, and would have less need for sunning themselves.
Evolution is just as much a religion as Creationism.
Saying that over and over doesn't make it true.
Yet Another Web Site
Lol, creationists are such a funny lot :-)
There's more evidence towards evolution (cosmic and biologic) than towards creationism, that's for sure. So no, it's not as much of a religion.
If you need evidence about the hydrogen stuff, go do a degree in physics (at a decent university). I just did, and trust me that's not mere fantasy. As for the biological evolution, darwinian selection works fine in every other system... why shouldn't it work in biology?
Daniel
Carpe Diem
Evolution is just as much a religion as Creationism.
To you, perhaps. Unfortunately, both sides sometimes overlook the details of evolutionary theory. Evolution is best described, IMO, as two different things and they often get lumped together. First there is the phenomena of evolution, that offsprint inherit the traits of their parents (or parent in the case of asexual reproduction), and these traits have the ability to change over time, for better or worse. Secondly, there is the theory of evolution, which is the entire lump of theories/hypotheses that describe the path by which we came to be over 5 billion or so years.
The idea that organisms can "evolve", as described in the first case is well understood and generally taken as fact, since we now have a pretty good understanding for the molecular basis of this macroscopic observation (DNA->Protein, central dogma, etc). If creationists insist on condemning this as not fact (even the vatican has accepted it), they will only further hurt their arguments.
I'm not an expert on the second case, but I believe quite strongly that knowledge of the first case is compelling evidence for the second, especially in light of all the other piles of observational evidence and the historical record that is available.
-Sean
Someone please explain --- flying involves generating lift away from the feet, but racing car spoilers generate downforce into the ground, so shouldn't they create wings of the opposite shape?
Maybe the important component was forward force rather than footward force, though by bending forward more a small component could be directed footward while most was directed in the direction of motion to get away from the predator.
The article also did not explain why it wouldn't be more efficient for the creature to use their front legs for additional ground contact, and evolve into a squirrel or lemur. If their arms were too short, they probably wouldn't provide significant force by flapping.
While arms are good for climbing stiff surfaces like trees, they might be less usful for climbing loose surfaces like sand dunes, or dead-leaf-covered hills in temperate climates, or mud swamps. (If it was dusty, maybe part of the strategy is to blow/flap dust rearward toward the predator?:) Any clues on what the environment was like where these creatures lived?
Did they have HUGE tail pipes and make loud vpppppt noises when they run?
...And when they came for me, there was no one left to speak out for me." - Martin Niemoeller (1892-1984)
One is limited only by imagination as to what series of intermediate stages enabled wings to become as cool as they are. (Okay, there are some biomechanical and developmental constraints).
Thus is the beauty of doing science without data. Hypotheses are uncontrained.
At the far extreme:
Aliens planted diosaurs... disprove it?
I'm not an expert on the second case, but I believe quite strongly that knowledge of the first case is compelling evidence for the second, especially in light of all the other piles of observational evidence and the historical record that is available.
Logically, evidence for the first case is not evidence for the second. It's a bit like any inductive proof, proving for n still leaves the proof for n+1. In evolution, we know micro-evolutionary changes through DNA mutations are possible. But that the process of mutations can be extended indefinitely back to a common ancestor is a seperate issue.
The only historical evidence available to support the second case is from the fossil record, which even www.talkorigins.org considers the 'weakest' proof for evolution. Our other observational evidence lies mostly towards 'mountains' of evidence for the first case, but only quite limited evidence for the second. Check www.talkorigins.org's list of evidences of macro-evolution for a decent listing.
Logically, evidence for the first case is not evidence for the second. It's a bit like any inductive proof, proving for n still leaves the proof for n+1. In evolution, we know micro-evolutionary changes through DNA mutations are possible. But that the process of mutations can be extended indefinitely back to a common ancestor is a seperate issue.
Like I said, I'm not an expert on evidence for the common ancestor theories. That said, while microchanges and adaptions through mutation may not by itself be evidence enough to satisfy, when combined with the DNA/RNA/Protein sequence evidence , it becomes rather compelling, IMO. (once again, I'm a bit out of my area)
It comes down to two options, an intelligent agent (god, aliens, etc) could have created the species' with DNA sequences that fit a mutational model quite well, or every organism could have a common ancestor and these sequences evolved naturally through mutation. If an intelligent agent created the species, why would it engineer the DNA/RNA/Protein sequences such that they looked exactly like they would if they got that way by eons of mutation? Occam's razor would tell you that natural evolution of those sequences is a far, far simpler and more likely explanation, especially in light of the fact that microchanges happen spontaneously and are commonly observed in the laboratory.
-Sean
> I've yet to see a single pair of fossils that
are close enough to one another to be a single mutation apart
You and your parents are several mutations apart. You won't find that minimal quantum jump in the fossil record.
> We should see all kinds of creatures and
evidence of past creatures that are similar, with relatively smooth transitions from one form to another. The just isn't any evidence of that.
No one is going to make you believe the results of scientific enquiry if you don't want to, but if you want to sound like an informed critic you're going to have to get informed first. There is absolutely nothing in the theory of evolution that implies that we should have the collection of fossils you are demanding to see.
Sheesh, evil *and* a jerk. -- Jade