It is without doubt that the earth is home to a wide variety of life that procreates similar but not identical forms. Those forms which are more suitable for th

It is without doubt that the earth is home to a wide variety of life that procreates similar but not identical forms. Those forms which are more suitable for the present environment are on average more successful in procreating while others have fewer or if their differentiation is particularly negative have none or even fail to launch as it were. We can observe especially in simple life with short generations accumulating changes. Claiming small changes don't accumulate would be like claiming water drips in a bucket but never fills up. There are plenty of arguments to be had about details and mechanics but there is no competing alternative to evolution. Do you disagree?