Do we Understand Heredity an Evolution? No

Genetics has long been regarded as the cornerstone of biological understanding—explaining how life reproduces, evolves, and sustains human health. Mendelism, including Johannsen’s 1911 genotype conception, which posits that ‘genes are the units of heredity’, supplanted Galton’s earlier phenotype-based statistical law of ancestral heredity. Yet, this shift was not the result of decisive empirical validation. Evidence accumulated over the past three decades challenges the genotype conception. In 1992, the discovery of radiation-induced genomic instability and the bystander effect undermined the assumption that heritable change is strictly gene-dependent. In 2009, genetic variance failed to account for the fitness trajectory observed in the Long-Term Evolution Experiment (LTEE) with _E. coli_. By 2013, it became evident that evolution in the LTEE was thermodynamically—not genetically—driven. This paper traces the historiography of heredity from 1880 onwards, critically re-evaluates Mendelism, and reviews recent empirical findings. It concludes that Mendelism fails as a scientific framework. Consequently, there is no valid consensus underpinning the life sciences, human health, or evolutionary theory. This represents a profound failure in twentieth-century biology.