No, but it is the best fit when it comes to evolution. For examples, why are dolphins air breathers? They have a very similar role as sharks, being fast aquatic predators that prey on fish, and evolution has certainly driven them to look very similar. But a dolphin's DNA shows that it is more closely related to an elephant than it is to a shark. Why would this be the case?
I think the argument that the same thing found in ten different species is proof of evolution is a bit weak. The argument would be stronger if the example was more specific. For example, if we take the forelegs of certain animals, say bats, horses, whales, humans, mice and elephants, we can see similarities in the way the bones are arranged that indicate that they share a common ancestor. This ancestor then divided up into groups that evolved the same bone structure to carry out different roles. The bones may have changed shape, but the basic arrangement is still the same. This is evidence of evolution, because it is unlikely that random chance would have resulted in such similar arrangements, and a designer would not have modified the same base to work for such different roles, he could have designed different structures perfectly suited to their intended role.
Evolution is a very broad subject and has many parts, so it's not possible to give a complete overview of the entire topic in a few sentences. But the basics of evolution are as follows:
Individuals in a population are mostly similar to each other, but they have slight changes between them. For example, all zebras are basically horse shaped and have black and white stripes, but some may have greater stamina than others, some may have poorer eyesight, etc. All the different characteristics of an individual are controlled by the genes in their DNA.
When two individuals reproduce, the DNA of their offspring is made up of a combination of the DNA from the parents, so the offspring tends to have characteristics from both of them. Also, so small changes can also happen due to errors as the DNA is copied as the offspring's cells divide. This means that the offspring can have different combinations of characteristics from the parents, as well as some slight changes that came from small mutations. This will gives the offspring different traits than those of its parents.
If the different traits are beneficial and help the offspring survive longer (say, better hearing, or stronger muscles), then the offspring is likely to have more offspring of its own. And when it does have offspring, those new offspring are likely to get the genes for these beneficial characteristics from its parent who had them.
On the other hand, if the traits are harmful (say more susceptible to disease, of more brittle bones), then the animal is likely to die before it can produce babies. Thus, the genes that cause the harmful traits are likely to be weeded out because any animal that has them is less likely to reproduce.
So, over many generations, the genes that bring about beneficial traits are likely to spread, and the genes that cause detrimental traits are likely to die out and no be passed on. This results in the population of animals gradually getting the traits that leave them well able to deal with the pressures they face in their lives, and they thus become better evolved for their environment. This process is called "Natural Selection", because nature is selecting what traits are passed on and which aren't.
So, evolution doesn't rule out God. It's perfectly possible to believe that evolution is a tool used by God. And evolution doesn't say anything about where life came from in the first place. Biological evolution is ONLY about how life forms change over many generations.
Hope that helps.
