Charles Darwin developed the idea that each species had developed from ancestors with similar features, and in 1838, he described how a process he called natural selection would make this happen. Darwin's idea of how evolution works relied on the following observations:

Darwin deduced that since organisms produce more offspring than their environment could possibly support, there must be a competitive struggle for survival - only a few individuals can survive out of each generation. Darwin realized that it was not chance alone that determined survival. Instead, survival depends on the traits of each individual and if these traits aid or hinder survival and reproduction. Well-adapted, or "fit", individuals are likely to leave more offspring than their less well-adapted competitors. Darwin realized that the unequal ability of individuals to survive and reproduce could cause gradual changes in the population. Traits that help an organism survive and reproduce would accumulate over generations. On the other hand, traits that hinder survival and reproduction would disappear. Darwin used the term natural selection to describe this process.

Natural selection is commonly equated with survival of the fittest, but this expression originated in Herbert Spencer's Principles of Biology in 1864, after Charles Darwin published his original works. Survival of the fittest describes the process of natural selection incorrectly, because natural selection is not only about survival and it is not always the fittest that survives.

Observations of variations in animals and plants formed the basis of the theory of natural selection. For example, Darwin observed that orchids and insects have a close relationship that allows the pollination of the plants. He noted that orchids have a variety of structures that attract insects - so that pollen from the flowers gets stuck to the insects’ bodies. In this way, insects transport the pollen from a male to a female orchid. In spite of the elaborate appearance of orchids, these specialized parts are made from the same basic structures that make up other flowers. In Fertilisation of Orchids Darwin proposed that the orchid flowers did not represent the work of an ideal engineer, but were adapted from pre-existing parts, through natural selection.

Darwin was still researching and experimenting with his ideas on natural selection when he received a letter from Alfred Wallace describing a theory very similar to his own. This led to an immediate joint publication of both theories. Both Wallace and Darwin saw the history of life like a family tree, with each fork in the tree’s limbs being a common ancestor. The tips of the limbs represented modern species and the branches represented the common ancestors that are shared amongst many different species. To explain these relationships, Darwin said that all living things were related, and this meant that all life must be descended from a few forms, or even from a single common ancestor. He called this process, "descent with modification".

Darwin published his theory of evolution by natural selection in On the Origin of Species in 1859. His theory means that all life, including humanity, is a product of continuing natural processes.

http://en.wikipedia.org/wiki/Introduction_to_evolution

OR

In Creationism, Special creation is a theological doctrine which asserts that the origin of the universe and all life in it suddenly sprang into being by unconditional fiat or divine decree.

http://en.wikipedia.org/wiki/Special_creation

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Imo, even though the evolution theory has some "holes", it perfectly explains how we got here and why we are different

lol 

Darwinian theory is a very good explanation of evolution, but it is not a very good explanation of the origin of life. Evolution is without a doubt, a fact. It is in the finer details that Darwinian theory begins to unfold. Until they can accurately determine how life started on this planet, no one should rule out any of the ideas as to how it happened. Life springing from primordial goop could be true, but that hasn't been proven yet. Watch Expelled for better explanations than I could give on the subject. Also, there is something out there besides Creationism, it is called Intelligent Design, and IT is not always religiously based. Creationism is a small part of intelligent design.

From what I know and conclude, many of Darwin's principles are right. I believe in adaptation and some parts of evolution. But I also believe in Intelligent Design.

I don't think its plausible to have interspecies evolution. A fish walking on land because it was born with lungs instead of gills. Adaptation is real, and thus that part of evolution is. Its proven everyday by all of us adapting to our society and environment. But I have yet to see interspecies proof that shows that we all originated from microorganisms, then fish, then amphibians, and so on. If you think about survival of the fittest, how would the offspring, the first fish that can now breath oxygen, survive the rough climate of land if that is the only part that had evolved. He would die. If evolution takes millions of years, then we may never know if this aspect of it is true or not.

That is why Darwinian Theory is hazy.  It could be how it happens, it could not be.  The problem around ID and DT is that the scientific community ostracizes the ID thinkers, by firing them, ridicule, etc.  Yet ID ideas are no less unscientific than saying that lightning struck some mud and life came about, or that crystals evolved into life.  While these things could be true, they have yet to be proven, and until they have been proven, the scientific community should embrace ideas that could fill in the gaps of DT.

Yes, I do. While like any theory it can (and should) be improved and perfected, it's the theory that explains the origin of species the best, without having to resort to any supernatural being, thus making it the most adequate for me

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Fundamentally Darwin created a theory that will be the basis to our final understanding of evolution.

@Jaggedsac, I love the way you laid out the problem with discussing Darwinism. At present, the religious bodies, creationism and intelligent design are not disproved or attacked by Darwinism. In fact most logical people could conclude that all Darwinism, Creationism and Intelligent Design could all be possible without disproving the others (although the extreme Creationist is specifically targeting Darwinism).

@Bursche, going over some of the more detailed biological similarities and differences different species share, it is possible to follow back these "trees" to a common ancestor. Darwinism doesn't specifically target these ideas of evolution, although modern thinking and extensive fossil evidence helps reinforce the idea that Darwins theories of evolution can be adapted to support the broader ideas behind evolution of different species.

Darwinian macro-evolution has been proven wrong in the form that Darwin argued it was in. It's not a gradual process that changed monkey into man (as seen in the made-up sketches that we all know of apes turning into neanderthals, into humans). His theories on micro evolution have indeed been proven right....So it's a mixed bag on what Darwin did for evolutionary theory.

darryl - Some Darwinists (especially in the scientific community) use Darwinism to attack IT/Creationism, so neither side of the argument are clean when it comes to targeting the other side.

I completely agree, right now in every argument or discussion between these two ideologies is absolutely ridiculous.  Both sides seem to see the other side as a complete attack on their own theory, when in reality there is plenty of room for both ideologies to be discussed without resorting to finger pointing.