Was the evolution a process of chance? an incident? Can it repeat itself somewhere or sometime?

The answer is yes to all your questions. Evolution does happen by chance and also individual instances. How evolution actually happens is still a question that scientists debate. Some questions are easy to understand, like how the zebra and horse could have a common ancestor. But others are not so easy. Vertebrate paleontologists are investigating that birds may have evolved from dinosaurs. If this is true, the evolutionary event happened over millions of years. Even though we know so much more about evolution than when Darwin proposed his theory, we still need to understand our natural world better before we can say for sure how species develop, how organisms become extinct, and the rate at which all this happens. There are many easy to read books about evolutionary theory that I would encourage you to read. Just ask your librarian for authors like Stephen J. Gould, Charles Darwin, Edward O. Wilson, Jane Goodall, Lewis Thomas, Jonathan Weiner.

Can evolution still happen? Sure, it is still happening. One of the problems with most textbooks is that they give the impression that evolution was a thing of the past; but it is not. Animals, plants, micro-organisms are evolving as you read this. Mankind is responsible for some "evolution" of animals in sheep, cows, chickens, and plants. Read about the flavor savor tomato. Look up some books about the breeds of cows and horses. Dogs are another great example. The history of corn is a fascinating story.

There are lots more questions to answer about evolution and you could be the future scientist to do it.