<edit: Gina's second case is the central idea to explain this. Here's a slightly more detailed explanation: >
Quote:
Originally Posted by FrozenJoe
Figs are propagated asexually by cuttings. That means that every Celeste should be identical to every other Celeste. Every Black Mission should be identical to every other Black Mission. Every Brown Turkey should be identical to every other Brown Turkey. But instead different strains seem to have developed within these varieties over time. Why is that?
It's because your first statement, though true, is also
not the whole story. Figs are not propagated
only by asexual means! Consequently your next three statements are false. It's true that figs are propagated asexually. It's also true that figs are propagated sexually. Why would you think that every Celeste is a clone of every other Celeste? That is not the case. Consider: If a Celeste variety can arise from a sexual reproduction (as undoubtedly happened at some point), then why would you want to assume that that event happened only
once in the history of the earth? And that every Celeste on earth was reproduced asexually from that one original Celeste? That would be the only way for every Celeste to be genetically identical to every other Celeste.
This is just basic biology and genetics. Even if other Celestes had the same two parents, they would be siblings (not necessarily clones). My sister and I have the same two parents, yet we are not clones of each other. We may be quite similar genetically (as you'd expect from us having the same two parents), but we're certainly not clones of each other genetically. Neither are any of my brothers clones of me (I have no identical twin or triplet). So even if the first Celestes had the same parents, they would be different. So even from a single pair of parents (if all Celestes were genetically siblings of each other), there would be different strains of Celeste (clones of the different siblings). But it is almost certainly more complicated than that... what if each of the two parents had siblings, or cousins, or distant cousins? Some of
their offspring would match the condition of being "Celeste" as well. So cousins of Celeste can be Celeste. If you go back in the ancestral chaining further, it could be second-cousins, third-cousins, etc. So the right way to consider what is a "Celeste" is that it is some kind of extended family (genetically speaking anyway). Probably a pretty broadly extended family, beyond what you might consider familially related in the human analogy. (Do you consider your 47th cousin your cousin? Odds are you don't know their names, because human record-keeping doesn't typically extend back that far in ancestry. But that doesn't mean that there isn't someone out there who is your 47th cousin).
Why do people refer to these as "strains"? It's just recognizing that there are variations in the individual specimens within a variety. They're close enough to be both recognizable as "Celeste", but different enough in their individual characteristics that it's useful to differentiate them if you care about those particular characteristics.
I hope this helps.
Mike central NY state, zone 5
p.s. Though all that's necessary to understand the above is the fact that figs are propagated both sexually and asexually, it also turns out that the particulars of sexual reproduction in figs is somewhat unusual. If you want to understand that, there are lots of references in Jon's reference section on the site. There's also a brief chapter (just a couple of pages) in Ray Givan's booklet. I think his chapter is called "The wierd sex life of figs" or something like that.