Throughout evolution, living beings have had to face and resist adverse conditions that tested their adaptive capacity. As a result, they have developed processes such as hormesis to ensure their survival and their ability to thrive in challenging environments. Currently, this process is recognized as a key mechanism that complements Darwin and Wallace's theory of evolution, making it necessary to explore its relationship with other processes linked to natural selection such as adaptation, adaptability, plasticity, variation, and variability, among the main ones. Subsequent research within the framework of Neo-Darwinism and Modern Synthesis better explains hormesis and the understanding of the complexity of biological responses. In this framework, there is a great need to put hormesis in context based on the laws of variation and inheritance and establish a consistent, updated, and expanded definition that allows the integration of hormesis with evolutionary processes. In addition, the biological mechanisms through which hormesis may be related to the evolutionary process are discussed.

Charles Darwin hypothesized that evolution is based on adaptations to a changing environment, and that organisms that developed even slightly favorable variations would ultimately be most likely to survive. This concept is clearly reflected in the life cycles of pathogenic species. While modern antibiotics, antiviral agents, and vaccines can successfully eliminate many pathogens and prevent infections, only susceptible strains are affected. Bacteria and viruses that can adapt and develop resistance mechanisms will survive and thrive in the absence of ongoing competition. We build on this framework by considering the evolutionary impact of microbial-mediated adaptations experienced by the host. For example, intracellular mitochondria, largely believed to be descendants of symbiotic ancestral bacteria, can be specifically targeted by viral pathogens. Taken one step further, we hypothesize that Darwinian theory may also apply to atoms and molecules, which are not "alive" by any conventional definition, but interact with one another and self-assemble according to the principles of thermodynamics that promote stability in defined environments. Building on these foundations, our hypotheses and conceptual framework will facilitate further exploration into the evolution of microbial mechanisms that modulate behavior, shape the development of the immune system, and promote host evolution.

see that this change is a result of selection acting on heritable variation in the traits within a population … that inspired Darwin to propose natural selection as the key mechanism of evolution. Or so the legend goes … categorize forms of natural selection which describe either the different outcomes of natural selection or

This article explores the historical development of evolutionary biology-from Natural Theology to the Modern Synthesis (MS)-and the ongoing debate around the Extended Evolutionary Synthesis (EES). Over the past 2,500 years, evolutionary thinking has emerged from the interplay between empirical discoveries and dominant philosophical paradigms. Beginning with Aristotle and Saint Augustine, we trace how Darwin and Wallace introduced a scientific framework grounded in natural mechanisms. In the early 20th century, the MS unified Mendelian genetics and Darwinian selection, forming a gene-centered model of evolution focused on mutations and population dynamics. In recent decades, discoveries in epigenetics, phenotypic plasticity, symbiosis, niche construction, and cultural inheritance have challenged the explanatory scope of MS. The EES seeks to incorporate these processes not by discarding Darwinian principles, but by reinterpreting them through a systems biology lens. This mostly represents a conceptual shift in focus: from linear, gene-driven causality to multilevel, reciprocal, and environmentally embedded dynamics. While gaining traction, the EES has been criticized for its lack of formal models and predictive frameworks, remaining a contested proposal. Ultimately, evolutionary biology continues to evolve as a powerful scientific tradition, driven by humanity's enduring quest to understand the origins and evolution of life on Earth.

A learning objective merges required content with one or more of the seven science practices. Natural selection only acts on the population’s heritable traits: selecting for beneficial alleles and thus increasing their frequency in the population, while selecting against deleterious alleles and thereby decreasing their frequency—a process known as adaptive evolution. Natural selection does not act on individual alleles, however, but on entire organisms. An individual may carry a very beneficial genotype with a resulting phenotype that, for example, increases the ability to reproduce (fecundity), but if that same individual also carries an allele that results in a fatal childhood disease, that fecundity phenotype will not be passed on to the next generation because the individual will not live to reach reproductive age. Natural selection acts at the level of the individual; it selects for individuals with greater contributions to the gene pool of the next generation, known as an organism’s evolutionary (Darwinian) fitness. Fitness is often quantifiable and is measured by scientists in the field.

Description Scretching Theory of Evolution III: A 21st-Century Paradigm Shift Applied to Neo-Darwinism, Mendelian Genetics, Allele Analysis, and Quantum Molecular Biological Closure is the third paper in a three-part series developing the Scretching Theory of Evolution as a five-level reinterpretation of Darwinism, Neo-Darwinism, Mendelian genetics, molecular evolution, and quantum molecular biology. The purpose of the manuscript is not to reject Darwinian selection or Mendelian inheritance, but to place each mechanism at its proper explanatory level within a larger physical-biological hierarchy. The paper argues that Neo-Darwinism remains scientifically valid as a theory of allele-frequency change shaped by mutation, recombination, inheritance, genetic drift, and natural selection. Mendelian genetics also remains valid through segregation, independent assortment, dominance, genotype ratios, and phenotype ratios. However, the Scretching interpretation proposes that Mendelian alleles are not merely symbolic hereditary units such as A and a. They are DNA sequence states with computable quantum molecular biological properties governed by the Scretching/JDCS equations of quantum molecular biology. The central thesis is that Mendel’s classical ratios remain mathematically correct, but they are recovered as probability projections of deeper molecular-electromagnetic closure states. Genotype ratios such as 1:2:1 and phenotype ratios such as 3:1 are preserved, but each allele and gen

new mechanism of evolution, operating alongside Darwinian evolution by means of natural selection … theory, the cause of evolution is natural selection acting on the inherited differences between … evolution through natural selection, and the Lamarckian idea of evolution through the inheritance

complement of observable characteristics. It is a key law or mechanism of evolution which changes the heritable traits characteristic of a population Natural selection is the differential survival and reproduction of individuals due to differences in the relative fitness endowed on them by their own particular complement of observable characteristics. It is a key law or mechanism of evolution which changes the heritable traits characteristic of a population or species over generations. Charles Darwin popularised the term "natural selection", co Darwin's argument in On the Origin of Species portrayed natural selection as a law which resulted from other processes: inheritance (including both the transmission and development of heritable material); what we now call 'phenotypic' variation; and the metaphorical struggle for existence among living organisms. The 20th century's dominant theories of evolutionary biology treated natural selection differently, as if it were itself a causal mechanism, the agency of which was attributed either to the machinations of selfish genes or to 'the environment'. Which meant that living organisms themselves dropped out of scientists' theoretical picture. Under the pressure of evidence, 21st century evolutionary biology has seen growing criticism of the 20th century's gene-centred view of evolution. In consequence we now have an array of extended evolutionary syntheses which have returned the agency of living organisms to the heart of the theory of natural selection.