Hello Juergen,
I cannot agree with the way you phrase it. Landracing DOES NOT start with adaptation, it starts with assembling diversity. So what you name “the first step of adaptation” is not the first step of the landracing process.
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I thank you all for taking part in the discussion; your contributions have helped me.
I am concerned with the (philosophical or scientific) question of which process maintains and constantly increases the diversity of individuals.
For me, this question is not conclusively answered by Darwin’s definition of “natural selection”.
Through (plant) breeding (artificial selection) we have lost a large part of the genetic diversity of our crops.
I am trying to find the path that led to the diversity of different individuals that the original landraces once had.
We are dependent on genetic diversity, on the diversity of different individuals, if we want to practice landrace gardening and plant breeding.
I think it is not wrong to know how “nature” maintains and increases (new) diversity…
In any case, “nature” does not just mix genes (characteristics) that are already present. For me, mixing what is already there and Survival of the fittest cannot explain the increasing diversity of individuals over the billions of years…
Natural selection acting on beneficial genetic mutation.
“Beneficial” only makes sense in the context of certain, given conditions; but “nature” must provide for unknown (future) conditions - and in this respect “survival of the fittest” makes no sense…
For unknown conditions only “Diversity of variants” makes sense…
So the question still is: How does “nature” increase the diversity of variants, even though it supposedly tests every single variant for its quality under given conditions?
There are new mutations happening all the time. Some are beneficial, which are selected for (increase in the population)
Other mutation are neutral (not beneficial but also not producing any negative consequences for the individual)
There are also negative mutations which are selected against.
When conditions change this offers neutral traits the opportunity to have positive effects and be selected for.
Hello Isabelle,
there is a difference between “Landrace Gardening” and “Adaptation”.
Landrace Gardening is about growing landraces for the sake of adaptation, artificial selection (breeding) or just to increase diversity.
Adaptation puts the focus to get adapted plants for a certain environment; it is only one possible part of landrace gardening.
So I am not very happy with the term “Adaptation Gardening”…
Mutations happen at the sexual reproductive stage. So in the future, we won’t only be working with new combinations of what was, but “what was” + any survivable mutations. I suppose deletions are also mutations, which signify “what was” minus some genetic information. Increasing promiscuity seems to further mutation along. It seems like diversity plays a necessary role because highly inbred corn only stays increasingly highly inbred, even at large populations, but to what extent diversity plays a role I am unsure.
About getting new traits…
I learned about an experiment which showed how a bacteria developed a new trait. It learned how to ‘eat’ alcohol instead of sugar. For that, the researcher had the bacteria sugar-deprived for I can’t remember how long. Years.
They weren’t looking specifically for this mutation. What was extremely interesting is that, upon the researcher, the mutation happened to different batches of the same bacteria, separated before the mutation happened, and the mutation happened in the different batches at the same time lapse.
This suggests that new traits happen under severe stress, and that this process is less random that what we want to believe. A corollary is that if you want to develop new traits, then you need to force severe stress on large populations of a species. The process is long, deterministic, and not guaranteed to suceed.
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