SFL-BIO01 The Species Fixed Law: A Theoretical Analysis on the Impossibility of Interspecies Evolution

For over 150 years, mainstream neo-Darwinian evolution regards cumulative random mutations as the core mechanism generating new species. This paper constructs the axiomatic system of the Species Fixed Law (SFL) to provide an alternative analytical framework for biological inheritance and species stability. We define two core universal variables: species intrinsic fixed genetic architecture G₀ and bounded intraspecific variation ΔG_d, and propose two consistent mathematical formulas: the genome composition equation G = G₀ + ΔG₍₊₎ − ΔG₍₋₎ and the cumulative variation limit formula lim₍T→+∞₎ ε(T)·T = 0. Three measurable invariant markers of G₀ are clarified, including fixed karyotype number, conserved core gene collinearity and species-specific embryonic developmental timing. Three independent empirical datasets covering artificial mutagenesis records, global fossil archives and extant biodiversity catalogs are applied to verify that all genetic changes only belong to intraspecific bounded adjustment and cannot fully reconstruct G₀. Three repeatable falsification criteria are put forward to test the validity of the SFL system. This manuscript serves as the foundational paper of the cross-disciplinary SFL serial, and its unified symbolic and logical rules will be followed by subsequent studies on human origin, biodiversity and nuclear equilibrium systems, offering a new cross-domain perspective to re-examine the logic of interspecies transformation.