Perhaps many Darwinian biologists take speciation on faith. It’s always someone else who has explained speciation.
Investigators initially thought that a completely reproductively isolated population of polychaete worms had been established in the lab.
TalkOrigins’s section on “The Fruit Fly Literature” is the single longest section of alleged examples of speciation in the FAQ.
When offspring end up having more chromosomes than normal, that is called polyploidy.
The TalkOrigins “Observed Instances of Speciation” FAQ claims it “discusses several instances where speciation has been observed.”