Most hyrbrids are sterile? I don’t think so.
One of the definitions of species is that they can interbreed. Thus, are the polar and brown bear really different species at all, or are they no different than different breeds of dog or races of people. The physical characteristics of human races vary just as much or more, and until recently they were fairly homogenus in their own areas.
Yes a donkey and a horse are going to have sterile offspring, but a Zebra and a shetland pony will produce a fertile hybrid.
Thank you. You answered my question. And you may well be correct about them not being sterile....but even IF they reproduce, you no longer have a grizzly OR a polar bear....just as the admixing of dogs produces schnoodles and labradoodles....nice pooches for those who wind up owning them, but they and their progeny are bereft of any purebred distinction.
Thanks again.