What do you propose as an alternative to evolution?
Adaption. Where a stock creature does branch out from a set firm, but it doesn’t branch out so far that it becomes an unrelated creature.
I dunno, maybe wherever the evidence leads? Scientists have hung onto Darwinism for years because, as Richard Lewontin said, “Our willingness to accept scientific claims that are against common sense is the key to an understanding of the real struggle between science and the supernatural. We take the side of science in spite of the patent absurdity of some of its constructs, in spite of its failure to fulfill many of its extravagant promises of health and life, in spite of the tolerance of the scientific community for unsubstantiated just-so stories, because we have a prior commitment, a commitment to materialism.”
There is no way to know exactly what happened in the past. Any theory would need a contemporary observer. Cambrian problem is big...but harder is the non life to life jump.
Something with some evidence. Why do we need to believe in evolution?