Avian Air Sacs in a Predatory Dinosaur
30 September 2008
I was talking to someone this summer about how dinosaurs and man have always lived together. I described the human and dinosaur tracks near Turkmenistan, Russia and down in Paluxy, Texas and showing examples of carvings that have accurate depictions of dinosaurs on them from hundreds to thousands of years ago. The response I got was "I know dinosaurs lived at the same time but you don't have to go back hundreds of years... they are still alive today as birds."
A research paper from Paul Sereno published showing new evidence for the hypothesis that dinosaurs evolved into birds because of dinosaur fossils found in Argentina. He writes, "Evidence from the fossil record for the origin and evolution of this system is extremely limited, because lungs do not fossilize and because the bellow-like air sacs in living birds only rarely penetrate (pneumatize) skeletal bone and thus leave a record of their presence."
The hundreds of changes needed to evolve birds lungs is hypothesized to have happened as follows:
1. Air sacks begin to develop
2. Adaptation of lungs to a flow through design (or more correctly, lack of design)
3. Creation of a mechanism to turn the lung into a four stage process instead of a two stage.
Since lungs and air sacks do not fossilize the evidence of this type of transition is not based on empirical evidence, but is based on bumps and divots on the surfaces of the bones. From these variations on the surface they expect to gain a better understanding of how this massive undertaking could have happened. The problem is that studying bones of a creature you have never seen before leaves large amounts of room for error, especially if you have already drawn the conclusion that this type of evolution has happened and now are just looking for the evidence. No bone is proof of evolution. You can never prove from any bone that its ancestors or its descendants were any different that it was. Thousands of years of observation has shown that animals always bring forth after their kind and do not change into different kinds of animals.
The paper also says, "The origin and evolution of avian air sacs may have been driven by one or more of the following three factors: flow-through lung ventilation, locomotory balance, and/or thermal regulation." Evolution does not create better organisms! Mutations cause changes in already existing material and for those changes to become permanent they have to occur in the DNA that is passed on, AND the descendants have to out survive everyone else. The lung can not decide "Today, lets try something different. Lets grow this sack here and see if in a million years it helps us any." Better ventilation, better balance, and better thermal regulation all need a total redesign of the existing systems. Useless parts are not going to hang around for millions of years on the off chance that another system will compliment them to create a better system.
- If any one change happens by itself it would be detrimental to the creature.
- Hundreds of mechanical and physical changes are needed to have a better final product.
- New genetic INFORMATION is required to be passed on to the next generation.
- Information never occurs without intelligence.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0003303
