It is not a simple story as there are a variety of different ways such adaptations can occur. These mechanisms, broadly labeled as epigenetic inheritance, can regulate the expression of genes as well as redesign the genes. The bottom line is that the adaptations are not unguided, they benefit the organism, and they are extremely complex. The evolutionary story is completely wrong. As one evolutionist admitted, the Modern Synthesis:
states that variations are blind, are genetic (nucleic acid-based), and that saltational events do not significantly contribute to evolutionary change. The epigenetic perspective challenges all these assumptions, and it seems that a new extended theory, informed by developmental studies and epigenetic inheritance, and incorporating Darwinian, Lamarckian, and saltational frameworks, is going to replace the Modern Synthesis version of evolution.
A new extended theory? This should be interesting, for it would have to explain how evolution creates mechanisms which, themselves, cause evolution (in the form of adaptation). I sense a just-so story coming on. In fact, evolutionists are already explaining this without losing a step. For instance (from the same paper):
Epigenetic inheritance should be favored in fluctuating environmental conditions that last for more than one generation (but not for very long) and may be particularly important in the type of environments experienced by many microorganisms. In such fluctuating environments, efficient epigenetic inheritance is likely to evolve (i) if the parental environment carries reliable information about the offspring’s environment, (ii) when the response to induction is lengthy and incurs a very high cost, and (iii) when recall is not an option or incurs too high a cost.
See, that was easy. Evolution just happens. So long as there is an advantage to a new design, then it will appear. That's how evolution works.
One of the best known epigenetic mechanisms is DNA methylation in which a methyl group is added to cytosine, one of the four DNA chemical letters. The methyl group is a sort of marker that can help to regulate the expression of genes. DNA methylation is accomplished via the action of a complicated molecular machine (DNA methyltransferase) that adds the methyl group at precisely the right location in the DNA strand.
So evolution configured DNA methyltransferase and the associated molecular information that tells it where to add the methyl group, so that later the organism and its offspring could benefit when certain environmental pressures arose. That's good planning--evolution is almost as smart as evolutionists are.
And to further complicate matters, this molecular marker can, itself, be modified. That is, the mark can be marked, thus adding another layer of information to the epigenetic mechanism. In this case, the methyl group is hydroxylated. And of course a different complicated molecular machine is required for the task, and the information of when and where to go to work is needed.
Evolution must have created all these processes and molecular machines so evolution could occur. But that’s not all. Recently researchers found differing methylation patterns amongst mice from the same litter, reared in the same environment. As was reported:
[Researchers] found regions in the animal's genetic makeup with strikingly different patterns. Moreover, these regions occurred among genes responsible for determining anatomy during early development.
In other words, variably methylated regions of DNA have been discovered, and such variability could lead to increased trait variability. Evolutionists speculate that this could help the population survive:
We're proposing that certain gene variants contribute to heterogeneity in populations. In a fluctuating environment, this gives generations more opportunity to survive.
And perhaps this new capability could help answer long-standing questions about how it is that evolution could work so well. As the article explains:
For more than 100 years, mainstream science has embraced the basic tenets of Darwin's view that characteristics that increase an organism's ability to survive and reproduce will be passed from generation to generation. … Characteristics that affect an organism's ability to adapt and survive in times of environmental change have been thought to arise by chance through random mutations in an organism's DNA. However, this view could not explain how such mutations, which arise only rarely, help organisms of every size and variety adapt quickly enough through time.
We already knew evolution was plenty clever. It created genes, chromosomes and alleles, horizontal gene transfer, introns, DNA methylation, and its additional hydroxyl signal just to name a few structures and processes. Of course there is a dizzying array of molecular machines choreographing this drama at just the right moments. All this so more evolution could occur.
And now we add another miracle to the list: variably methylated regions of DNA so future generations could survive when some unforeseen environmental challenge arises. The levels of absurdity to which evolutionists will go is truly remarkable.