A convergent feature of evolution is a feature that exists within biological entities, which has arisen again and again, independently. Wings is my favorite example. Fish have wings of certain kind. There's flying fish. Butterflies have wings. So do eyes, so do organs for sound. How many times has that arisen on geological history of the earth in one species and one species alone? Can we conclude on that basis that it's inevitable that intelligent species will arise? If you were to repeat the experiment by sprinkling a little bit of bacteria around all the bio friendly planets that exist throughout the universe, would you be guaranteed to get a entity us?