Evolution has no goal
Brief thoughts on the driving action of natural selection
There’s a common misconception that evolution is “seeking” fitness — that there’s some inherent motivation in the process pushing toward a particular objective. Maybe this starts out as a misuse of language, an unintentional implication through poor choice of words, but I think there’s something to it. If you listen to people talk about how evolution works, they speak in human agency-like terms: that evolution is a process chasing after some idealistic trait or survival strategy. But it’s a lot dumber and simpler than this.
Evolution is an undirected process of mutation, testing, and accidental discovery of fitness. Within the genes of an organism, there is no memory acquiring feedback from these experimental genetic guesses.
Genetic drift, mutation, and natural selection are evolution’s conjecture and criticism. But the criticism feedback loop doesn’t close in a single generation.
Evolution’s feedback loop is survival. There’s no way within a single organism’s lifetime that its genes have any idea whether they specify useful traits. If a gene survives, it will replicate. If it doesn’t, that mutation is “found” not to have worked, though the genes themselves never receive the message directly1. A gene’s only goal (if one can call it that) is to copy itself. The environment provides the pressure to select one mutation over another. But the environment has no goal either. It merely is, and genes evolved to continually mutate, then they prod at the environment through random guessing (mutating) to keep replicating.
Though from the Big Bang to now it appears evolution is seeking ever-higher forms of intelligence, this too is deceiving. There are no known steps on the ladder. There’s no “global maximum” on offer.
As Stanley and Lehman wrote in their book Why Greatness Cannot Be Planned, the way to novelty is through continuous pursuit through the “adjacent possible”. Try the next nearest thing, see if it sticks, then take the next stepping stone. Evolution is a sort of upward spiral of trial and error.
Further complexity often confers an advantage, but not always. This fact is one that fools us into thinking evolution is in search of higher-order complexity on purpose. From the days of the primordial ooze, life mostly has gotten much more complex. But still, simplifying can work. Some bacteria are among the simplest, oldest, and most effective organisms evolved on the planet. They didn’t need complexity or intelligence, size or agility or strength to survive.
We’re fooled into assumptions about intention and goals because we humans have a tendency to seek patterns. Because we ourselves can conceptualize abstract goals and plan our choices in advance, we imbue evolution with a similar characteristic. The fish first evolving its way to crawling on the beach with hybrid fin/legs isn’t on a mission to eventually grow wings and feathers. It’s the complex and eons-long interplay between organism and environment that generates the continuous cycle of mutation, death, survival, and reproduction that eventually happens upon wings.
This evolutionary process still leaves us wanting on the subject of meaning. If the primary mechanism is a survival and self-perpetuation of genetic material, we still have to wonder why. We could take a religious perspective on the origins and objectives of life, and there very well may be something there. People of faith would make that claim. There is certainly a great deal we don’t know about the cosmic origins or purpose of what’s going on.
My point here only involves the mechanisms we can observe, understand, and ultimately explain. We can explain the operating action of evolution in these goal-indifferent “don’t die” terms. We can’t (yet) explain in scientific terms the “why” of the origins of life, or what it’s all for.
Evolution is a soup of primitive ingredients continually mixed, matched, and tested against a chaotic surrounding environment. When thought of as its own form of knowledge creation distinct from the way human-created knowledge works, it’s a helpful mental model for thinking about all forms of complex adaptive systems.
The theory that genes receive feedback within a single generation is called “Lamarckism”, a fascinating subject in itself. A story of humans projecting our own means of knowledge creation on evolution’s purely undirected, emergent process. I think we want Lamarckism to be true. We want to believe we have that much agency over our own genetic development.