Genetic Surprise Confirms Neglected 70-Year-Old Evolutionary Theory | PhysOrg.comHow species could arise that were incapable of breeding, and producing viable offspring, with their close-relative species, had always been a puzzle to me.
This article explains that it is accomplished by having a critical gene HOP OVER to a DIFFERENT Chromosome!!
From the Article:
"That was really exciting," says Masly. "It was completely unexpected and it made the cause of this hybrid's sterility very simple; the gene's on number four in one species and on number three in the other, so when you mate the two, every now and then you'll get a male with a combination that includes no gene at all. These guys are sterile because they completely lack a gene that's necessary for fertility."