There's more to evolution than natural selection

Life's complexity cannot be explained by random mutations alone

A colorful illustration featuring six birds perched on branches, showcasing a variety of species with different plumage and patterns against a natural backdrop.

Neo-Darwinian orthodoxy holds that life’s immense variety emerged through the action of natural selection on random genetic mutations. But, argues microbiologist James Shapiro, there is strong evidence that the mutations driving evolution are not random at all, but rather are the result of organisms modifying themselves. This upends the orthodox picture of life’s complexity as emerging out of simpler, lower-level physics, in a bottom-up direction. Instead, to understand complex living organisms we need to see biology as influencing the level of physics, in a top-down direction.

 

Since the mid-20th century, the neo-Darwinian explanation of evolution has been scientific orthodoxy for the public: change comes from the gradual accumulation of random small mutations resulting from accidents in genome replication, and natural selection favors the survival of organisms with the “fittest” combination of mutations that permit them to reproduce more successfully than other members of their species. Given enough time and divergence, these gradual changes can add up to the formation of a new species. This is the story we find in popular accounts of evolution, like Richard Dawkins’ The Selfish Gene and Daniel Dennett’s Darwin’s Dangerous Idea.

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Living organisms alter their own heredity. This scientific reality means that the time is long overdue for a radical revision of the neo-Darwinian orthodoxy about how and why evolution works.

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There are serious statistical questions about the ability of random mutations plus gradual natural selection to produce the tremendous variety of genomic innovation observed in the evolutionary record. But the most curious feature of the neo-Darwinian account was the absence of any biological self-modification in the processes generating new organisms. Now that we can determine how hereditary variation arises by following mutational and evolutionary events with genetic analysis and DNA sequencing, it has become abundantly clear that biological cell functions, including those for DNA damage repair and genome restructuring, are the major (perhaps the only) significant sources of genome change in evolution. To be clear, this means that living organisms alter their own heredity. This scientific reality means that the time is long overdue for a radical revision of the neo-Darwinian orthodoxy about how and why evolution works. To illustrate why this revision is needed, I will focus on one of the most important examples of biological self-modification: the ability of cells to mobilize particular DNA sequences throughout the genome.

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The story of biological genome change activities starts with a remarkable woman named Barbara McClintock. She pioneered maize cytogenetics before we knew about the DNA double helix (1953). Cytogenetics (literally “cell genetics”) was the science of correlating genetic changes with microscopic examination of the chromosomes in the cell nucleus. By the 1930s, McClintock could see that her maize cells recognized X-ray-induced breaks in their chromosomes and could join the broken ends together. When ends from two different breaks join, a novel chromosome structure forms. McClintock showed how structural changes can influence genome content, genome expression and chromosome behavior at cell division. These are all basic features of evolutionary change.

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Kevin Rigley 22 March 2026

James Shapiro is right to say that neo-Darwinism is too passive. The old orthodoxy has always depended on a strangely lifeless picture of life: random mutations drift upward from below, selection trims the waste, and complexity somehow appears as if by patient statistical accident. Shapiro is right to revolt against that story. Organisms are not dead matter waiting to be sculpted. Cells repair, restructure, transpose, edit, and reorganise. Life is active. But Shapiro’s correction still does not go far enough, because it risks replacing one simplification with another. Neo-Darwinism made the organism too passive; Shapiro makes it too central. In both cases, the environment is treated as though it were either a static filter or a passive stage. It is neither.

Darwin’s deepest insight was never really about genes. It was about persistence. The environment selects what persists. That remains true. But humans have introduced a dangerous novelty into that equation: through metacognition, language, institutions, and technology, we do not merely adapt to environments — we build them. And once we build them, those environments begin selecting back. That is the point the modern argument keeps missing. The real evolutionary drama is no longer just in mutation, nor even in biological self-modification. It is in the recursive loop by which human minds alter the conditions of development, and those altered conditions determine which traits can now endure.

This is why the Anthropocene matters far beyond climate or pollution. It is not just an environmental age; it is a selection age. We have changed food, sleep, speed, schooling, sensory load, family structure, stress rhythms, and social expectations. We have saturated childhood with novelty while stripping away recovery. We have created developmental ecologies unlike any in human history, then pretended to be surprised when different forms of cognition begin to stabilise within them. Rising divergence in neurotype is not simply a story of better diagnosis, nor of hidden genes finally being revealed. It is also the mark of an environment that has been radically rewritten. If neurotypes are emergent, then the modern world is not merely detecting them — it is helping select what can persist.

This is where both Shapiro and neo-Darwinism fail in different ways. One says evolution is driven by random variation, the other says it is driven by self-modifying organisms. But both understate the most disturbing truth: humans have made selection recursive. We have internalised Darwinian pressure into our own systems of living. We now engineer the developmental conditions that determine what kinds of minds, bodies, thresholds, and vulnerabilities are more likely to endure. The selector is no longer “nature” out there. It is the world we have built around ourselves.

That means the old comfort of blaming genes, or even praising biological creativity, is no longer enough. The real question is harsher. What kind of environment are we making, and what kind of human being does it reward with persistence? Until we ask that, we will keep telling flattering stories about evolution while ignoring the fact that we are now among its chief instruments. We have not escaped Darwin. We have become one of his mechanisms.

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