[Martin J Sallberg (OP)]

Why is it claimed that Mendelian genetics should be incompatible with Lamarckian evolution. A modernized version of Lamarckism involving gene duplications under environmental stress actually predicts the existence of Mendelian genetics as a rest position.

There is evidence for full genome duplications generally coinciding with major climate change. In theory, duplications of the whole genome should be fatal, and yet they have happened. Survival of full genome duplications requires tight epigenetic control, and in a novel way untested by natural selection since a full genome duplication is a saltation. This means that gene activity regulation must have been "warned" that the genome duplication was coming before it actually happened, and acted thereafter. In other words, non-random genome duplication. After all, microbiology as well as immunology in multicellular life shows that "hypermutation" tend to specifically target the offending part of the genome that needs to be changed, which cannot be explained by cells simply being too weak to repair mutations in general. So while duplications of small parts of the genome are triggered by minor environmental stress or simply a need to correct a genetic defect, full genome duplications are triggered by need to adapt to very big changes.

That tight epigenetic regulation turning off parts of the duplicated genome is effectively the formation of recessivity. The duplication itself explains the origin of non-haploid genomes. Standard Mendelian genetics is then the rest position ruling alleles that does not strongly need correction, which usually refers to the vast majority of the genome and therefore the vast majority of cases when you pick a specific gene pair (or set if the organism is triploid or beyond). So while neo-Darwinism just takes Mendelian genetics for granted, a modernized Lamarckism explains where it comes from!

Is the false dichotomy just because Lysenko denied Mendelian genetics? Forget him, he was ignorant of gen(om)e duplications.