I will start with a generalised genetic disproof of inheritance of acquired characteristics from Wikipedia.Genetic disproof
There are many formulations of the genetic disproof, but all have roughly the same structure as the following:
Acquired traits do not affect an organism's genome.
Only the genome is passed to the offspring.
Therefore, acquired traits cannot be passed to the offspring.
While this proof may be logically valid, it suffers from the material fallacy of begging the question, since no one who believes in inheritance of acquired characters would believe both assumptions.
My theory throws these assumptions away and replaces them with this observation. The inheritance of acquired characteristics is not evident because the genome has embedded within it thousands of generations of experience as to what genetic traits are worthwile and those that aren't. In *general*, genetic mutations mimicking acquired traits do *NOT* make the organism any *fitter* to survive in nature.
Instead, the following rules of regressive evolution apply:
-Genetic mutations in offspring are a result of stresses on the parent(s).
-Mutations have a directed element that depends on the exact stress involved.
-The directed element is programmed into the genetic code via association between the stress which is acting as a trigger, and the mutation which has been "proven" to be appropriate to survive better under new conditions indicated by the stress.
-The strength of association between the trigger and the mutation is entirely dependent on the reliability of the trigger being an indication that the mutation is appropriate to the new "environment".
-Many of the mutations concerned are simply switching on or off complex functions that are permanently programmed in the genetic code whether they are active or not.
-Certain combination of stresses may create combinations of mutations without precedent in itself, but each mutation would have been "field tested" individually in distant or more recent history.
Examples that should be quite clear-cut:
Darkness stress: Species adapted to cave conditions or permanently underground (moles etc.) are uncannily blind whereas their closest relatives have full sight. The stress of being in darkness your whole life would cause a considerable proportion of your progeny to have genetic vision defects - all other things being equal.
Wetness/dryness stress: Kamerrers experiments on the midwife toad (Chapter 7 Panda's thumb) had some merit. Clearly, one must separate the selection pressure from the stress trigger to prove the point that mutations to switch back on genes that helped in water are not evident without the wetness stress. Experiments need to be formulated with this in mind. River-courses changing their path makes sudden changes in local environments.
Radiation stress: In Earth's history every single large scale event would have radiation associated with it. Volcanoes erupting, asteroid impacts, solar activity, and possible magnetic field fluctuations would all send rare radioactive elements in the atmosphere or increased radiation. Is it any wonder then that the most obvious, largest scale mutations are caused by radiation? It is a clear signal that radical mutations in any direction might cause some to survive better.
"Regressive evolution" as a term has been almost exclusively used in describing reduction of features, such as in the loss of eyesight and pigmentation in cave dwelling fish. In "Marconomic" terms, reduction in features is also the clearest example of it in nature. Switching off something that was there appears a backwards or downwards move, while the re-switching on of a previously inactive feature appears to be either a leap or not a truly new feature, depending on whether it had been observed before in related species. Philosophically speaking, backwards, downwards and leaps are artificial concepts based on thinking of evolution (falsely) as a ladder rather than the reality of it being a "bush". Switching on or off of features that are then passed on is adaptive either way. Thus I group losses and gains of such features in the same "regressive" boat.
I call it "regressive" evolution because the process almost always borrows tricks that have developed in the past with selection pressures optimising them. Switching them off saves resources when conditions dictate they are unnecessary. However, they are there for when they are required, and perhaps almost all of the evident "faster" evolutionary processes have borrowed perfectly working genetic tricks and combined them in new ways.
At first glance regressive evolution is not really evolution because it never introduces truly *new* changes. However there is such a large number of possible combinations of trigger-responsive genes that the number of species in the Earth is dwarfed by it. If there is a million genes that can be switched on or off depending on triggers, that makes two to the power of a million possible combinations. Virtually all of them will be truly new changes. Also triggers will almost always produce a spectrum of mutations - This is because the future cannot be predicted perfectly. Chance, probability and statistics is a big part of the process. Truly random mutations, however are almost certainly an evolutionary dead-end.
So I have said that in *general*, genetic mutations mimicking acquired traits do *NOT* make the organism any *fitter* to survive in nature. However, this begs the question: Is there any *specific* genetic mutations that do? (Mimick acquired traits that triggered the mutation)?
The trait/mutation would have to fit the following conditions:
A) The organism must be in a state of life or death stress or reproduction-challenging stress(1)
B) The "situation" must be very analogous to situations repeated in the genealogical history (2).
C) The mutation must clearly help progeny in analogous stressful situations more than just being shown/trained/helped by the parent(s) etc. (3)
D) The disadvantages of the mutation must be clearly outweighed by the advantages given assumed environmental constraints. (Needs a clear cost/benefit advantage)
(1) It is not enough, for instance, that a giraffe stretches their neck reaching for higher food. For a trigger situation, the giraffe must see other giraffes dying of starvation, be short in food itself, and endure the frustration of seeing lots of leaves just out of reach. (Using a well known Lamarckian example) If it isn't a life or death situation, the mutation will be both unecessary and resource-depleting.
(2)The "knowledge" associated with the trigger must be on firm statistical ground. The trigger will never be something only associated with proximal individual adaptation. For instance one 1930's experiment devised to investigate inheritance would chop of an insect's antenna that generally grows back. Any number of generations "experience" would not offset the natural experience of the insect, which is - that a more ideal regrowth of an antenna is unnecessary for survivability and reproduction in any conceivable natural environment. Even if it was - chopping off an antenna would not be an indicative trigger.
(3) It is tempting with certain features, to assume that if strength in one arm is important to survivability, and a person strengthens that arm for a greater part of their life to suit their job, and that their children are likely to have the same constraints - that a genetic mutation that would strengthen that arm without as much training would have evolutionary merit. However, if the feature is being passed on to the child by training from the parents, and very few are dying due the the arm being too weak, a mutation may be less reliable than just letting the parents train their children specifically.
A Rundown of evidence that supports my theories:
1) Experiments show that general mutation rates increase as a result of stress.
2) Humans and bacteria have some parts of their genome that are extremely similar. Even though these same parts are quite resistant to random mutations (ie. random mutations do no noticeable change to the organism). As with most parts of the genome, the specific functions of these segments are unknown.
3) Natural selection needs mutations to select from. Stressful situations lend themselves to particular mutations. This article lays out a clear example of adaptive mutation. Because almost no research is looking for similar adaptive mutations, it is unclear whether this is the exception or the rule.
4) My theories do NOT rule out random aspects to the process. Genes that *Are* under constant selective pressure will have (seemingly random) mutations and will use natural selection as a process of refinement, quality control and mutations that don't affect the purpose of the gene will build up in that gene over time -*at well researched rates*. Selective pressure is the error-correcting mechanism in this case and certain critical sequences can stay the same for Billions of years by this mechanism. This fits in perfectly well with my theories.
5) The apparent extension of this randomness into virtually all genes fits the data quite nicely. However, this should not rule out that the apparent randomness overall, is due to the randomness of the factors that cause mutation triggers. The orthodoxy is that the apparent randomness rules out environmental feedback causality of most of the overall apparent mutations. As pointed out in (3) there is some clear counter-examples to the orthodoxy.