well think about it...
speciation requires many cycles of reproduction-maturation-reproduction to occur. even if a certain phenotype is naturally selected by the environment and the animal thrives, it will be many generations until that beneficial trait combines with other beneficial traits to produce an entirely new species. a lot of the beneficial mutations are pretty minor too.
if you want an easily understandable example of evolution, consider the flu virus. Each year a new vaccine is distributed; if the virus didn't mutate to be immune to the previous year's vaccine every year, we wouldn't need to get vaccinated annually.
or why we have "super bugs".
or the overproduction of antibacterial solutions. Since they have become popular, a lot of bacteria have become immune to them.
I know these aren't desirable examples of evolution, but it happens every day. whenever the 0.1% of bacteria survives the lysol spray, natural selection occurs.
how do you think dogs came to be, anyway? people saw that an animal for guarding or hunting could be beneficial to them, took in the wild foxes and wolves that were most friendly to them, and bred the ones that were the most friendly and obedient, with softer fur, etc.