Quote Originally Posted by Chris in Hamilton View Post
So if the hybridization had occurred by some chance a thousand years ago and the progeny of that cross interbred naturally to become a plant with its own distinctive characteristics wouldn't that then be a distinct species?
Yes, eventually, understanding that a species is whatever is defined as such by valid publication, and generally accepted over time. It could just as easily be considered a variety of one species or the other. There is no set number of generations or years, it could potentially be a shorter time or much longer. There is no set amount of difference that constitutes a new species vs. variety. It would have to be a stable breeding population no longer showing segregation of characteristics of the original species, and it would have to be effectively reproductively isolated from both original species. If it wasn't reproductively isolated by distance or biology, it could be more a case of 2 species blending into 1, or having a permanent zone of introgression (natural hybrid population) between them.

---------- Post Merged at 08:24 AM ----------

Quote Originally Posted by Dorsetman View Post
Quote ; There are reasons why examples of a natural hybrid and a man-made hybrid from the same species may differ. The natural hybrid isn't just the first generation cross in most cases.

Well said, and I must say I have never heard that before, nor thought of it myself . But it is so obviously right. The next time I am asked about this, I shall quote your words.

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A very clever question - I'll bet that would floor most biologists.
Thanks Geoff, but I am sure the reasons for differences between natural hybrid populations and man-made hybrids are not original thoughts with me. Still, it is fun to know I can make an experienced grower think in a new direction.

And as far as the issue of when a new species evolves from a hybrid population flooring biologists (like me, by educational background), I'm sure many would give an answer similar to the one I gave Chris. Most biologists are quite comfortable with the concept that species is a fluid concept with no firm boundaries, and there is often an arbitrary aspect to where we draw the line.