Sorry, I was being a smart alec about introgression, never a good idea. There is a lot of philosophical territory here that maybe isn't quite appropriate for Steerplanet, but why not? From my 5 minute study of this word that is new to me (but the idea seems to guide me), introgression can occur naturally, or can be accomplished through genetic engineering. A smart alec might suggest that we splice an intention to evolve into the genetic technology so that the organism can short circuit our scientific notions of what is profitable.
I am always interested in what old time breeders "see" when they study cattle. The breeder knabe referred to early in this discussion figured this out through observation, I assume, not genomic analysis. Even if you ask and even if you are told what bloodline carries a trait, you have to be able to see what you are looking at. I have a friend who thinks people don't spend enough time on observation any more, because the world has gotten so full of demands on our time. I think there is truth in that. It's like when big pharma synthesizes a drug that grows wild in the Amazon, making the Amazon irrelevant.
So, knabe says
i guess one thing i don't understand or forgot, is how thousands of small effects don't get lost due to error, especially if the training population is diverse and the pathways have little overlap between individuals. to me, this marbling thing seems to be left over pathway energy as opposed to any direct effect.
i forget the papers, but there is these little cells, and their number and distribution and distribution density may vary, but for some reason, they fill with fat, or lose fat or something, depending upon available energy and it's use, ie foraging in the wild versus statically in a feedlot like a glutton.
be says
That part gets more to what I am pondering. What would be the natural history of that left over pathway and what would have been the trade off. It seems analogous to obesity in native human populations who have evolved on a low carbohydrate diet and then been switched over to white flour and sugar. Big trade off in survivability for an increased ability to store fat.
Wikipedia tells me, "Introgression is an important source of genetic variation in natural populations and may contribute to adaptation and even adaptive radiation.[1"
Our attempts to reclaim the ability to fatten on grass alone across diverse environments seems to call for releasing the gene pool from streamlined combinations of ultimate fitness for the feedlot to get on with re-adaptive radiation.
and this from knabe
What I'm really after within any breed is a way to capture the difference in expression and allow producers to introgress the combinations they want, validate them and make breed crosses if they so desire and make combinations they want.
How would you make this capture? Would the introgression be natural or technological?