Question

In his recent monograph on botanical phenotypic plasticity, evolutionary biologist Marcus Calder argues that transgenerational DNA methylation patterns constitute an autonomous hereditary mechanism capable of driving rapid adaptive divergence. Calder’s rigorous molecular assays of clonal dandelion lineages under thermal stress provide compelling empirical documentation of heritable epimutations that persist across dozens of generations without sequence alteration. Nevertheless, Calder’s broader assertion—that such epigenetic marks operate entirely free of conventional genomic constraints—overreaches what the data currently warrant. While his experimental protocols establish that stress-induced methylation variants can endure, he has not yet ruled out the possibility that cryptic nucleotide substitutions govern the initiation and stability of these epigenetic states. Consequently, although Calder has uncovered an important dimension of environmental responsiveness, his claim to have decoupled epigenetic adaptation from traditional genetic architecture remains premature.

Which of the following phrases best describes the author's attitude toward Calder's proposed model of transgenerational epigenetic inheritance?