Wheat is already a hexaploid hybrid. It has a particular gene that causes
it to sort out chromosomes effectively. Deletion of this gene makes
chromosome sorting a mess, leading to infertility. Thus, it is probably
partuclarly good at further hybridizing.
>Regarding issue (2) I recall that Darwin seemed to lean on hybridization as
>a most important method by which to generate the variations that natural
>selection acted on. The more modern thought usually relies on gradual
>accumulation of small (or medium/large - Punc Eq) mutations. Perhaps
>naturally occurring hybridization is an important mechanism. Creationists
>(YEC or PC) rely strongly on the species (or genus) barrier to distinguish
>"micro" and "macro" evolution. This kind of cross makes the
>Neanderthal/Sapiens cross look small.
In plants, formation of new species and genera by hybridization is rampant.
It is harder to do in animals, because plants can reproduce asexually but
many animals cannot. However, in some animals (notably certain lizards) a
hybrid can reproduce parthenogenetically.
David C.