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Post by raymondo on Aug 23, 2011 6:56:09 GMT -5
An interesting post. I followed a few of the links but sadly they ended up pointing nowhere (error 404). I didn't follow them all though. I would love to read the original articles referred to in some of the sites.
As an aside, it's worth remembering that epigenetics is really only about gene expression, not gene modification or inheritance, and so is not equivalent to Lamarckian theory. Modern work in epigenetics has, however, sparked renewed interest in the ideas of Monsieur Lamarck.
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Post by oxbowfarm on Aug 24, 2011 6:11:45 GMT -5
some of us still believe in Lamarkian genetics (epigenetic) in some sense, and i for one believe the environment has a much larger effect on genotpye (and indirectly phenotype) than we actually realize. That dosen't mean that it itself isn't governed by natural selection, or is exactly like Lamark originally imagined, but saying that it has been proven wrong is nonsense. Be as skeptical as you want, but clinging madly to either darwin or lamarck (or anyone really) is a bad idea. Darwin really didn't study genetics. He did write about some processes that seem to coincide with genetics which have turned out to be helpful and in many cases invaluable, but i don't think we should worship the man. I think it's important to keep reevaluating what we know about the world, and to constantly challenge those ideas. I think whenever possible we should do our own experiments and try and notice more than we already do. Keen, my apologies if I offended you. I did attempt to caveat my statement enough to avoid this but clearly failed. It is entirely possible that I've misread the meanings of the original post. I have no problem with the concept of epigenetics, I believe in it, but my understanding of how it works precludes Lamarkism. My understanding of an epigenetic effect is that it can only occur if there is a pre-existing genetic component for that effect in the genome. Epigenetics being the method by which organisms turn on or off portions of the genome. So a kind of nuanced process whereby an organism becomes more adapted to a specific location by selectively expressing or repressing different aspects of its innate genetic potential. My understanding of Lamarkism is the idea that the necessity for a new adaptation would spontaneously generate that adaptation in the organism ex nihilo. I certainly accept that there are many things I don't know and will never understand. I am sorry if my post burned you a bit. I hope I don't madly cling to Darwin. I have a hard time worshiping anyone, but I'm honestly much more fond of Wallace. He just seems like a much harder worker, much more humble, plus he independently theorized natural selection in the steaming hot jungle while busting his hump working for a living. JMO. All I was really saying was the original post was quoting some really significant yield/productivity increases. I just would like to see this verified from other research. If it works it would be awesome. |
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Post by keen101 (Biolumo / Andrew B.) on Aug 24, 2011 10:03:49 GMT -5
oxbowfarm, no you didn't offend me, but i do believe in a lot of things most people don't, so whatever. Okay, so maybe epileptics isn't quite what lamark was talking about, or maybe it is. We still really don't know that much about it, and other process going on. I believe we will continue to learn things that we thought we already knew.
Obviously Giraffes did not get longer necks in one generation (lamarks famous example of creatures that spontaneously adapt), but perhaps his theories are correct for bacteria. Bacteria seem to have the ability to spontaneously adapt to antibiotics and other stresses in one generation, and they are so good at it that it is causing epidemics of disease from time to time. So, from my point of view saying that lamark was entirely wrong seems a bit premature. Yeah he was kind of wild (actually one of the reasons i like him), and many of his ideas did turn out to be wrong, but i don't think completely turning away from him would not be fair.
Also i figure that if bacteria can adapt so easily and probably even create spontaneous mutations because of environmental stresses (some of which might make them survive, or some that might make them die quicker), that humans probably can do some of the same, but at a much slower and minuscule scale. And plants too.
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Post by spacecase0 on Aug 24, 2011 13:28:55 GMT -5
I think that the conditions can reprogram the DNA,
when you start looking on the small scale cells are just like computers,
the hard drive would be the DNA,
they have the equivalent of RAM and shift registers and all,
why would it not be possible for it to not only turn on and off some sections of the DNA but also to rewrite them if needed,
all the hardware is there for it to do such things,
and the operating system stored in the DNA (currently referred to as junk DNA) is way beyond what science has figured out as they have just identified it as an operating system
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Post by 12540dumont on Aug 24, 2011 16:36:17 GMT -5
The following is from "An Orchard Invisible: A Natural history of Seeds." ..."Barbara McClintock who won a Nobel Prize for her discovery that some genetics don't obey Mendel's laws. What she discovered was that some genes don't follow the choreography of the chromosomes, segregating in Mendelian fashion to give predictable rations. She deduced that there are genes that jump around the chromosomes, sometimes playing havoc with the genome. These transposons act like free agents, multiplying themselves when their host is at stress. About half of the corn genome is made up of thousands and thousands of copies of selfish DNA." Corn is very interesting. It does not disperse it's offspring. Somebody must pick a grain and plant it the following year. This interdependence between man and corn is very complex and the process of selection evolves both of us. Corn has a lot of threshold traits...converging influences that added together create. sfmatheson.blogspot.com/2007/10/they-selected-teosinteand-got-corn.html (Corn evolution short and sweet). The more I farm, the more I realize I know nothing. Except it's hot and I've fled the fields to can green beans and think about corn. Joseph's corn, Alan's corn, Cortona's corn, Canada Mike's corn, and the corn that I have in the field thanks to someone who put the grains in her pocket for next year. |
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Post by Joseph Lofthouse on Jan 3, 2018 2:53:13 GMT -5
Posting a shoutbox dialog from January 2018.
Day: I read a blog the other day and the author mentioned breaking off the tip and base of the corn cob and only saving seed from the middle. He didn't elaborate, so I was wondering if anyone here could explain the logic behind saving corn seed this way.
paquebot: Before hybrids, an uncle saved Golden Glow. The tip end was broken off and the small kernels not saved. On the base, the big kernels were not saved. It was for planting purpose as the seeds had to be uniform size for the plates.
Day: Huh, very interesting. Makes sense too. The weird thing is, this gentleman plants by hand, not machine. I wonder if he just does it out of habit, having learned that way (maybe whoever taught him used machines) or if there could be another reason. Curious. 15 hours ago
Walk: I use center of the cob kernels as they are the biggest without being misshapen. Years ago I read there were two thoughts on this: one is by being "selective" you can make improvements, the other is don't disrespect/discard anything the Creator put there.
Andrew: Yeah I've heard if you select middle kernels you can get more uniform good size cobs and kernels in future generations. Also heard if you select the big fat kernels at the end they get bigger over time. I think both are just myths though.
oxbowfarm: Butt kernels are the first silks to emerge, tip silks last, so planting them will change the variety DTM. There are more powerful ways to select for this though, the main reason to avoid them is they are oddly shaped and don't plant mechanically well.
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Day
gardener
When in doubt, grow it out.
Posts: 171
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Post by Day on Jan 3, 2018 20:20:40 GMT -5
Joseph Lofthouse - When I started the shout topic I figured it would be a simple, straight forward answer (something I should already know the answer to, basically.) Wasn't sure where to put all this new knowledge once it was gained though, at least in terms of threads. Thanks for the save! It probably would have taken me a bit of back searching to find this thread... Glad to know it exists! And now I'm curious to learn more on the topic, both in terms of corn, as well as other plants. For example, does the order of inside a bean pod mean anything? How about the center circle vs outer circle sunflower seeds? Much to think on and research! I'm going to have to read through this thread more closely, see if some of it is already here.
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Post by reed on Jan 4, 2018 9:34:30 GMT -5
To a large degree I'm still working toward maximum genetic mixing in my corn so I save seed lengthwise up and down the ear. Especially if it was a favored mother plant and or de-tasseled. I figure that gives highest chances of lots of different fathers depending on who was shedding pollen at a particular time.
[add] I went back and read all of this thread. I'm pretty much of a novice so take it with a grain of salt but the original post sounded a little goofy to me. I liked Joseph's response where he talked about virus load and other factors being the driver of differences in yield rather than a seeds location on the plant.
It reminded me of my KY Wonder pole beans. For years I grew these beans with my preference for seed coming from pods with as little as possible spotting on the dry pods. My beans don't even look like KY Wonders anymore. Seeds are larger and lighter colored, pods are longer and straighter, blemished pods are rare. I do save seed from earlier pods rather than the left overs at end of season but have never paid attention to location on the plant.
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Post by walt on Jan 4, 2018 15:13:14 GMT -5
I would think this would be the proper way to keep so-called "heirlooms" perpetuated over the long term but I doubt people have been doing this, or doing this consistently, which is why I think many of today's heirlooms are shadows of the originals. I think a lot of folks would and still do harvest for food and then simply leave some pods on those plants to save a few seeds for the next season. I would think such a method would seem intuitive for most people. That is unintentional selecting, probably towards the negatives, because the best pods or the pods most representative of the variety likely ended up on the dinner table or in the canning jars. reed - your experiences kinda prove these thoughts out to me, although it sounds like you have improved on your KY Wonder by observing and intentionally selecting some of the best pods for seed rather than using them for food. So did your selecting create improvements that no longer make it original to the heirloom variety it once was, or did they make it closer to what the original once was? Who knows but I suspect the latter. You have now, through selection, made your own KY Wonder "Improved" or perhaps "Recreated" strain. I think many of the heirlooms out there could use some improving via selection. My point is one shouldn't assume an heirloom in its current state is good or properly representative of the original just because it is an heirloom. An heirloom may have been very good when it was originally released and marketed but that was a long time and many plant generations ago. When I was an okra breeder in Niger, a lifetime ago. I noticed that most okra was very late maturing. Niger has a 5 month "rainy" season, which is actually rather dry. Then there is a 7 month dry season without a drop of rain. So most people's okra was maturing after the rains had stopped. Very few had okra that producedover most of the rainy season. The reason was that they just left a few of the final pods dry on the plant and harvest them for seeds 7 months later when it was time to plant. Early production was no advantage to the plant from an evolutionary point of view. Those villages that chose there seeds from plants that bloomed and produced all season had a steady production of pods all season. This was good as the fresh pods are a good source of vit. C. Dried okra can be a good source of protein, but why not have the green fruit all season. If the rainy season was normal length, both kinds of okra produced the same amount total. If the rains ended early, which it does often, the early kind's yield wasn't hurt much. Over time, the way you harvest and select your seeds matters, whether or not your system is thought out. |
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Post by walt on Jan 4, 2018 15:25:10 GMT -5
Joseph Lofthouse - When I started the shout topic I figured it would be a simple, straight forward answer (something I should already know the answer to, basically.) Wasn't sure where to put all this new knowledge once it was gained though, at least in terms of threads. Thanks for the save! It probably would have taken me a bit of back searching to find this thread... Glad to know it exists! And now I'm curious to learn more on the topic, both in terms of corn, as well as other plants. For example, does the order of inside a bean pod mean anything? How about the center circle vs outer circle sunflower seeds? Much to think on and research! I'm going to have to read through this thread more closely, see if some of it is already here. For some years I was breeding perennial sunflowers, so I read everything published on sunflowers up to the mid-1980s. One paper said a study showed seeds on the outside of the head had more DNA than those on the inside. I don't know if that is true as I didn't find the paper that referred to and I didn't check it out myself. Anyway, based on the first paper I didn't see, the author of the second paper had compared the seedlings from the outer seeds with the seedlings from the inner seeds. No difference was found from sprouting till harvest. Commercial hybrid sunflower seed are sold to farmers with number of seeds per pound on the label. Some farmers buy the bigger seeds thinking the crop might get a better start. Studies show no difference. It seems that sunflowers have been selected to the point that the have more energy than they need. |
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Post by RpR on Jan 4, 2018 16:24:05 GMT -5
I am assuming then, that when I open my new corn packets, I should discard, or give to the squirrels, seeds that are smaller.
I have in the past, taken the winky seeds and rather than ignore them, put two in a hole.
The part of potatoes really intrigued me. Does he mean the potatoes at the bottom of the hole are best for replanting?
If next year I save a few cobs and take the very large ones from the butt, how will that affect the next crop?
I plant by hand so machine problems do not exist.
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