>>I’m assuming you believe it happens when species evolve?
Splicing (cutting and rearranging / inserting code) is only one factor that can result in the modifications to an organism's (and a species') genome that drive Natural Selection. Other common factors are radiation and chemicals in food/water/air.
Anything that modifies genetic coding creates a new genotype - and it is the change in genome that drives Natural Selection by effecting and affecting the fitness of species.
One simple measure of the new genotype's fitness is the number of reproductively viable offspring produced over multiple generations.
Observe the process in the context of viruses...
...and the beneficial (to viruses anyhow) resulting diversity of viral species.
For species with a lower rate of reproduction, the impact upon fitness becomes more visible in the context of relatively large and stressful environmental changes. A simple definition of stress being - some condition that requires an adaptation to maintain a population.
The stress could be something like an ice age, a famine, a communicable disease, the discovery/manufacture of a new food source (like alcohol, the poisonous aspects of which some individuals are better adapted to than others), or an invention - of something like warfare, or TV.
Some humans are immune to deadly infections like Ebola and HIV. How did that happen? Something adaptive happened somewhere in the history of their genome.
https://www.google.com/#q=Natural+Resistance+to+Ebola
Of course many (most?) adaptations are less than beneficial for the host - for example:
“Viral oncogenes are responsible for oncogenesis resulting from persistent virus infection. Although different human tumor viruses express different viral oncogenes and induce different tumors...”
http://www.ijbs.com/v06p0730.htm
[[Anything that modifies genetic coding creates a new genotype]]
Only within the boundaries of species specific information- as mentioned before, species have several layers of protections that prevent them moving beyond their own kinds
[[and it is the change in genome that drives Natural Selection by effecting and affecting the fitness of species.]]
I had asked about evolution, not natural selection- NS works on species specific info- it doesn’t add new non species specific info- it can’t add spider silk mechanism to a bat or rat- it can onyl alter what is already present and allowed by the species protective mechanisms
[[For species with a lower rate of reproduction, the impact upon fitness]]
Again, we’re not discussing fitness or NS- I had asked about splicing resulting in new non species ‘allowed’ or ‘specific’ if you prefer, info (IE splicing adding in info to create silk in say a wombat, or a platypus bill into a goat- I’m not aware of any such splicing that creates new non species specific info out of nothing but a mistake
[[Some humans are immune to deadly infections like Ebola and HIV.]]
Resistance doesn’t = macroevolution