At one point in time i believed genetic drift did occur after a few generations of cloning clones of clones of the original mother plant from seed. My original plan or strategy for my garden and cloning was grow the plant taller and take bottom branches after controlled lst to force the bottom branches grow long enough to clone then i would lollipop and only difference was i cloned the bottoms (they were max 4 inches long) and my result no matter how vigorously the original mother was time and time again were the same. My yields were diminished and after about 3 generations of cloning my clones grew about 25% slower and with about 25 % less nodes each generation that i took clones from bottom branches. One day i was sitting there with my favorite pheno of any strain i ever found on my own from seed and i watched an 11 leaf frostitute I call my Dirty Wompa O.G and im looking at my probably 7th generation from clones that were all from bottom branches and by now all my tops on all my clones are all miniaturized and the space between my nodes doubled leading to way less top growth than that of a vigorously growing clone. So this led me to feel confused at first, thinking about all the landrace phenos that people have cloned over and over and so on and so forth by cloning the clone thereof and some of these legendary clone only phenos are still growing strong long spears of frosted up medicine to this day. So what happened different or what could be the reason for genetic drift to sometimes occur? Could it really be they were possibly using weak branches for their next generation of that clone only pheno or that next cycle of that mother plant you have from seed. In my experience with Dirty Wompa O.G she went from having 11 leaf on all her newest leaves but now my clones only have 3 to 5 max as a result (ironically like the undeveloped malnutritioned bottom branch that turned into the clone that it is. What happens next is I move into a place with my grow partner and we begin and carry on my garden of strains i had at the old place now growing at the new place. We promptly changed alot about our gardening strategy. We began taking a couple of the healthiest top branches on all the plants while we still structure them to be bushy in veg, it was after about 3 generations of us taking burly top branches (these clones being 10-14 inches long consisting of 3 nodes under the collar line and 4-7 nodes above the collar or soil line) as our next generation plants we began to see the nodes on Wompa O.G tripled in amount to x amount of stem, all of the tops were growing healthier, faster, and thicker than their bottom branch counterparts were. We began using this new methodology for our cloning strategy. Since then all of our phenos that we got as clones and started from seed at one point ourselves seem to grow bigger and better each time now instead of degrading like before. There is always other variables in the garden than what meets the eye but in my experience i see that its best to use your branches that have the most vigor for clones, just like when picking seeds strong genetics are first step to great end results. Why would you not want to use the fastest healthiest branches to use as your cuttings that you will root and use for your next generation of plants. This is my theory on the possible causes that could make the possibility of genetic drift between clones an actual possibility to begin with.