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by Ma8ee 616 days ago
> since the DNA and gene expression of an individual actually changes during its lifetime, and those changes can be passed down to offspring through various mechanisms.

That statements need a whole lot of backing. It contradicts the Central dogma of molecular biology [0]. The idea that an organism can pass on to its offspring physical characteristics that the parent organism acquired through use or disuse during its lifetime is called Lamarckism which was disproven more than a hundred years ago.

[0] https://en.wikipedia.org/wiki/Central_dogma_of_molecular_bio...

3 comments

There are several processes, many of them documented on that very page, that allow an organism to pass on certain characteristics that happened during its lifetime to at least the next generation. One other example of such a process is horizontal gene transfer, typically through viruses, but also sometimes in plants through grafting.

For an extremely simple example, if a female organism is exposed to significant doses of radiation, the DNA inside the egg cells it was born with will have a high chance of suffering mutations. If one of those eggs remains viable and later gets fertilized, the DNA of the offspring produced from it will be significantly different from the DNA that of offspring born before the radiation exposure.

There are other more subtle and more common processes, though. The most surprising one is that DNA methylation, a process in which environmental stimuli encountered in a living sexually mature individual affect gene expression, has been proven to be transmissible to offspring across several generations in certain species. This includes stimuli such as prolonged exposure to heat or cold, long-term starvation, and others. This is indeed a form of Lamarckism that has actually been proven to happen, though of course it involves much subtler changes than some of what Lamarck envisioned.

We absolutely pass on traits to our children based on things that happen to us. See the study of epigenetics: https://en.wikipedia.org/wiki/Epigenetics
The article you link includes a section on types of information transfer that this human-originated rule does not apply to...