Two plant species interbreed and produce hybrid offspring. These offspring are unable to reproduce with either of the parent species, but they are fertile when breeding with each other. which of the following can you infer from this information?
1.) allopatric speciation has occurred as a result of interrupted gene flow.
2.) hybrid zones fused and have caused reproductive isolation.
3.) sexual selection has formed a new species due to prezygotic barriers.
4.) sympatric speciation has resulted in the formation of an allopolyploid species.