Been a while since the last post... Time to enter the debate!
Let me start by stating my credentials. I am not the most intelligent person, but I always try to think my arguments through. My IQ is roughly 121. I am currently in an Australian University studying Microbiolgy.
Now, as for my argument:
I am going to point out a few things I know about life. Things which are rather obvious.
1. Everything that lives will eventually die. Be it Disease, famine, predator, accident, not knowing water depth and jumping, everything that is alive, or will be, will die.
2. Something that is not suited to it's environment is more likely to die. Examples: A crocodile out of water, Plant in constant shade, slow rabbits etc.
3. While things are alive, most of them will reproduce. These reproductions are not clones. Life reproduces with variation. Easily observable, just notice how you're different from your parents. The exception to this rule are creature is reproduce asexually, but even these mutate to create variation.
Because life reproduces with variation, life is constantly changing. In an unchanging environment, if a species has a high survival rate, few changes will occur over long periods of time. If the environment changes, and the species is no longer well adapted to living there, the changes will be more dramatic.
The term 'more dramatic' means that while individuals will still look very similar, the whole population will change in a certain evolutionary 'direction' very quickly. The individuals who are best at surviving in the environment will reproduce more, causing certain features to be more prominent, and/or others to be less prominent. In some cases, two populations of the same species, in the same environment, will begin to diverge. The populations have to be somehow separeted, or else the gene pool will be flooded by the other. The separation may be an earthquake caused fissure leaving half the population on each side, or perhaps a diverted river.
I haven't found evidence for it, but it seems to me that if behavioural conditions cause certain packs or herds to remain separate, despite no other barrier stopping interbreeding, speciation could occur. This would probably take much longer, considering the likelihood of outliers who cross to another herd or pack.
Eventually, the separate species have varied so much that interbreeding is no longer an option. This is when they are considered 2 different species. I even have an analogy for how a reptilian-like creature(RLC) could have evolved into a bird.
Based on observed facts, we can choose a group of RLC's who lived in trees. The survive on a diet of insects and plants. A RLC is born with slightly lighter bones. This gives him the advantage of being able to jump higher, and use less energy during the course of life. He survives longer, and reproduces more, because he can get more food, and is less susceptible to death due to fatigue. There are other factors, but they don't play a particularly significant role. His genes are passed onto the next generation, some with lighter bones, some with heavier, but all lighter then the average of the last generation. This trend continues, creating lighter and lighter bones, until a compromise is reached between survival through extra resources, and death through broken bones. The original mutation could have occured a number of ways. It could have been a random mutation caused by mutagens in the diet, or environment; it could have been a result of a particular combination of genes; etc..
To answer the obvious statement: "Bone-density doesn't make a bird", I say You're right! But the idea behind my logic can be applied to wings, feathers, beaks.... basically anything. The thing it can't work for, are things that don't originally give a benefit, even if the might eventually. It uses the argument "what's the use of half a x" as evidence for evolution. AND, whose to say that only one change can occur in a population at a time? While bone density is improving, perhaps vestigial wings are developing, or scales are growing into feathers.
And finally, evolution has no aim, no foresight. It has no hindsight either. Whatever works right now is what is selected. And, NO! I am not suggesting something is guiding natural selection, other then the energy, and fertility, of the individual beings, and the choices of the sexual chooser. (By this I mean when a certain sex selects a mate based on appearance, or dominence)
Now, hit me with your best shot! I want to hear counters to my explaination, flaws in my argument and other such things. I especially want to hear from Athiests, and Evolutionists (I know, not a real group, but used for understanding purposes). If you come at me with a stupid argument, be prepared for an equally stupid response. I'll do my best to answer all responses.