When learning about "crossing over" and later when teaching it in High School, I was under the impression that it was a random mutation. The combination of genes without crossover would be limited without the crossover events.
What I did not expect was to discover that crossover events are routine(1). Not only that but they are not random but are facilitated at specific sites(2). These facts altered my perception of the role of crossing over in facilitating different combinations. Where once I perceived it as a blind accident which helped organisms adapt to their environment I now view it as a planned event designed to help organisms adapt to their environment. To use a theological term it is the providence of the Creator.
This change in how I view crossover to the benevolent providence of our Creator subtly changes the frame of reference. Instead of seeing it as part of an evolutionary toolkit that produces new species, I have come to view it as a conservation measure allowing an organism to adapt to changes in the environment. What once appeared to be "evidence" for evolutionary progress, I now realise is actually "evidence" of the Creator's providence.
(1) "On average a human chromosome participates i two or three crossover events during meiosis, and every chromosome participates in at least one. Thus wheras two genes very close
together on a chromosome almost always end up together in the same gamete after meiosis, two genes at the opposite ends of a chromosome are no more likely to end up together that
are genes located on different chromosomes." The Molecular Biology of the Cell, Fourth Edition, p1137
(2) "There is strong evidence that the general genetic recombination events in meiosis are catalysed by recombination nodules".
The Molecular Biology of the Cell, Fourth Edition, p1136