The nuance I would add is that biology and inheritance are a bit messy. We would not expect phylogenies based on DNA and morphology (i.e. morpho=shape, how a species is shaped) to exactly match one another if evolution is absolutely true due to mechanisms such as incomplete lineage sorting, homoplasies, and the number of species we have to test these hypotheses. What scientists look for is the phylogenetic signal which rises above the messy noise of biological inheritance. Like almost everything in biological research, the statistical significance of the match between phylogenies is what counts. Talkorigins actually has a half way decent primer on the basics of the statistical testing.