In addition to Lamarck, kindly also remember Michurin. He was the first who openly opposed the accepted notion of that time that "genes can't be affected by external environment". Michurins experiments were simply ignored and as pierre has pointed out that Mendel's laws were "true" only "for times".
Post by keen101 (Biolumo / Andrew B.) on Nov 6, 2016 22:42:06 GMT -5
an interesting question gilbert since your emphasis is on little to no "conscious selection".
I will reply with an interesting story from my own garden a few years back. A few years ago i was working on heavily selecting my indian corn to have heavy amounts of purple leaves, purple stalks, purple seeds, purple pollen, etc. In the midst of that corn patch was plenty of bindweed and grass. The grass was curious as it was green. But after that year, the grass in that spot was mostly red. Even in years between my planting of purple stalked corn. I'd say that for about 3 years after that grass remained heavily reddish. Even when no corn was grown there for a few seasons.
Now this is not to say to my corn somehow pollinated the grass and affected it genetically that way as that's not really possible. But i do think that chemicals and genetic expression markers from the corn were leached into the soil which then had a strong influence on the genetic expression of those grass plants. Perhaps even to the extent of slight epigenetic changes. You can draw your own conclusions as you see fit.
Though, my best guess is that through little human selection epigenetic changes do occur, but very slowly unless there are heavy environmental selection pressures. From my own experience the biggest environmental influences on what thrives in my high altitude, high UV, low humidity environment are: 1.low humidity and soil evaporation. 2. High UV. Some seeds i plant and they die even with heavy watering. I believe this is partly due to having poor root genetics for my soil and not being able to conserve water well. High UV may play an important factor here as well, but i don't know how much.
So yes, maybe somewhere between 3-5 years each strain would grow slightly better in their new adopted habitats. Just my opinion though. I've been working on the watermelon thing for awhile and they still barely grow. But slowly but surely we are getting closer. Up to this point though i have tended to do little selection in favor of mass pollen sharing instead. I may have to start being more aggressive in my selection pressures if i want to make more progress at a quicker rate.
Also, too bad i did not get a picture, but this is the first year we got ripe pears from the grafted pear tree. Oddly a few, and one in particular had partially green, partially brown skin of varying degrees per pear. The one i ate today had the most brown and appeared to be a regular yellow pear on the bottom and a brownish harder (maybe asian pear) pear on the top. The bottom actually tasted as it appeared and the top tasted like an asian pear. I liked the top half better. So what going on in this case?! I believe it is a case of two grafted trees sharing sap which affects the genetic expression of the fruit in unexpected ways. I once heard of a similar happening with an orange-lemon grafted tree. As was reported to me, the lemons kindof tasted like oranges and the oranges kinda tasted like lemons (presumably because they were sharing sap). This reminds me of the Michurian fellow and his work mentioned above.
The Michurian stuff is really interesting when you think about his experiments with grafted plants being more receptive to interspecies crosses. Presumably because the sharing of sap also shares chemicals that lets the plant accept "known" pollen and reject others. Makes me wonder if his technique could improve interspecies crossing rates of certain projects like Josephs tomato and squash interspecies crosses. Would a grafted pimpinellifolium tomato on domestic tomato rootstock (and the reciprocal graft) be more likely to cross?
Kindly try to find out Michrin's work on net regarding this matter and try to apply that on your own garden. As you are already into this, I am sure you can do the job. But, don't forget to take pictures and have journals of what you are doing and what you have achieved. That will be a big proof.
Post by Joseph Lofthouse on Nov 7, 2016 1:13:22 GMT -5
I'm coming to think that epigenetics plays a much bigger role in my plant breeding than I have been lead to believe by mainstream science with their focus on Mendelian genetics. I'm even wondering about inter-species communication and collaboration.
I can't even document the Mendelian genetics that is happening in my garden, so it would be doubly hard to document the epigenetic happenings.
Silt/clay, high-altitude, super-arid, sun-drenched, irrigated-desert garden. Cold radiant-cooled nights. ~100 frost free days. Grow most of my own locally adapted landrace seed. GDD10C ~1300. Buy my book or subscribe to my newsletter at Lofthouse.com.