Theory of Large Changes

The Theory of Large Changes

Any evolving system (living, innate, cultural or technical) must compose of evolving elements ('individuals' in living systems).
But it is a property of the universe, and becomes an inherited property of living elements, that some attributes are easier to change than others.
This will force a stepped effect on any evolving system, because for individuals it will be more efficient (fitter) to modify the easy-to-alter attributes first. While new, hard-to-alter attributes will only evolve in concentrated efforts, after all the easy-to-enact modifications are consumed.
We can show, with some qualifications, that this process applies to how life evolved on Earth.

(Note: This essay is mostly observing that stepped changes occur in evolution. So those already aware of this might want to skip straight to 2.0 The Theory of Complex Accumulations. Those not aware might visit Evolution Debate Explained. So far, the essay lacks a mathematical proof of why the easy and hard to evolve attributes cause the stepped changes.)

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In this Section:

1.1 The Basic Argument

1.2 Easy and Hard to Alter Traits

1.3 Evolution as a System

1.4 The Pattern of Evolution

1.0 The Theory of Large Changes

1.1 The Basic Argument

We all agree how evolution works.

In any generation more individuals are born than can survive and reproduce.
But among any set of individuals, genes* produce small, random variations, which render some individuals slightly better fitted to the conditions for life.
Natural selection chooses from among this variety those organisms best adapted to reproduce and pass their genes into the next generation.
We can measure the success of an individual to pass on its genes as the fitness of the individual.

Numerous studies, mathematically and among living species, have proven that for an advantage as slight as an improved mutation of a single gene allele, the best adapted organisms are also the most fit. *(Note: Most variation is established genes rearranged on chromosomes. Evolution of totally new genes is a less frequent event. See Smart Gene Hypothesis. Also, most new genes are regarded as evolving by point mutations within a gene. In fact, new genes might evolve by gene doubling or copying, as orthologous evolution.)

Yet, while this model works for small accumulations over short genetic distances, we have no proof it will apply, at least uniformly, over large distances producing the major taxonomic changes of life.

We assume that mutation rates are roughly constant and fitness and selection apply all the time. Yet, species do not modify at constant rates.
Especially, evolution of new taxonomic groups seems to occur in sudden "bursts" of evolutionary activity that we call a radiation.

The usual explanation of these stepped changes is that they are driven by random external factors such as large geological change or accidents of prior taxonomy. But while we do not dispute that evolution unfolds within a backdrop of random changes, even for a smoothed backdrop of minimal change evolution might occur in a stepped manner. This is because in any evolving system some attributes are easier change than others.

In the universe some geometric shapes, molecules, or other structures are inherently more stable and efficient than others and these properties shaped early life.
So, when the first organisms began to replicate some attributes would be stable but hard to change, while others would be less stable, but easier to modify. Only in evolution each individual is always striving for a slight fitness advantage.
Yet most times the fittest move is a simple adaptation, such as taking an already perfected attribute (like a limb) and modifying its shape, size, length, or function. Most evolution, most times, is this type of adaptation.

But occasionally in evolution;

All existing designs that can be quickly adapted are consumed.
A group of individuals is pushed into a niche where no existing design can be adapted to new requirements.

In these conditions, also by small, slight fitness gains (smaller and slighter than current theory allows) a new novelty to meet a unique circumstance evolves.

1.2 Easy and Hard to Change Traits

At any stage of evolution some traits are always easier to modify than others.

It is easier to vary the shape of a wing, which occurs all the time, than evolve the material "feathers", which evolved once.
It is easier to adapt the function "limbs" into arms, legs, flippers, and wings, which occurred many times, than evolve the four-limb body plan, which only occurred once.
It is easier to alter non-expressed DNA, which occurs every gamete, than evolve totally new genes, which occurs once in about 10⁵ gametes.

So, small changes over a long time will transform a flipper into a leg, or into an arm, a wing or even back into a flipper again. This process is not in dispute. But once it has evolved the first time, no amount of small changes will allow a four-limb body plan to evolve again, nor will small changes allow feathers to evolve again. We can say that feathers evolving once only is an accident of taxonomy, or in future feathers might evolve again. Yet, a pattern of some attributes evolving once only while other attributes (like the shape of limbs) modify indefinitely is consistent throughout evolution. Plus the more primitive the function, the deeper the asymmetry between easy and hard to change attributes.

The easiest attribute to change in life is the DNA sequence, which varies once per gamete. But the most enduring attribute of life is the DNA code, which could only alter its present form if life were wiped out, and had to start over.
The most variable, easy-to-change living unit is the cell. Yet cell structures codified around a few basic types over a billion years ago, and no new cell structure will evolve again for present life on earth.

Although it is not the usual meaning of these (see Use of Terms) we define the two types of changes as follows;

Hard-to-evolve attributes are often termed homologous, but we will also call them monophyletic, in that they had a single, once only origin. So feathers, limbs, or the DNA code are monophyletic attributes, which evolved only once.¹

Easy-to-evolve attributes are often termed homoplastic, but we will also call them polyphyletic, in that they can have multiple loosely related origins. So legs, flippers, or many DNA sequences are polyphyletic attributes, which can evolve many times.²

1(Note: there is a debate if RNA evolved first, which is likely, but if DNA evolved separately in prokaryotes to how it evolved in eukaryotes and achaebacteria. So RNA is monophyletic, but the double helix shape of DNA and its substitution of a U for T nucleotide could be a pre-biotic homology.)

^{2(Note: Terms monophyletic and polyphyletic mostly apply to taxonomy. Here they mean "once only hard-to-evolve" or "many times easy-to-evolve". It is hoped the inference is understood.)
We assert then;

In any evolving system it is always more efficient to modify the easy-to-change attributes first, by evolving huge varieties around a basic theme.
Only after the designs based around a given set of hard-to-evolve traits begin to saturate, would it pay to evolve more complex technologies, through a singular but concentrated effort, and start the whole cycle over again.

So, for living evolution, it would be more efficient to vary polyphyletic attributes until all the easy changes are consumed, then evolve fresh monophyletic attributes in a massive, concentrated effort.

1.3 Evolution as a System
Above it is asserted that life evolves as a 'system'. But life is a collection of individuals, each struggling for reproductive fitness and not concerned with how life evolves in totality. Except we can show that individual fitness determines how the system evolves.

When individuals can only survive by evolving greater complexity, their lineage will tend to loose fitness over fitness rewards available at less complex levels. (So individuals try to avoid this).
But once a niche in which individuals struggle becomes saturated, the system itself is saturated for a given level of complexity.
When this happens some individuals are expelled from comfortable niches and forced to accept reproduction at reduced the fitness levels, as an alternative to extinction.
Tension between the need of individuals to maximize fitness, and a requirement of some individuals to increase complexity even if it means a fitness loss, checks and balances the entire system.

So fitness not only optimizes the adaptation of species, but it keeps the process of evolution itself efficient. This places a new requirement on fitness, not considered in the old theory.

We always assume in evolution organisms increase complexity to enhance fitness (that is why they "evolve").
But in life, the simplest organisms already enjoy the highest fitness. (See Theory of Complex Accumulations.)
So, organisms increase complexity not to gain increased fitness over simple organisms but increased variability to express fitness at all, once niches where only simple organisms can survive become saturated.

This argument appears strange, but if genome fitness could increase without limit for each increase in complexity, evolution would be a heterogeneous race to increase complexity. Nothing would force a "stepped" pattern, such as individuals forming species, or species forming into large groupings such as classes or phyla. We say that sex forces individuals into species, but early life was asexual. Plus the evolution of sex also involves a loss of fitness for an increase of complexity. This is what the new theory is predicting will happen, but it has not been explained within current theory. (Note, Hurst and others are confident that they can explain sex in terms of the existing theory.)
Yet once there is a fitness price for increasing complexity individuals will first seek fitness at the lowest complexity levels available, varying by easy to change ways from basic designs. Even then, it will not be until lower levels of complexity become saturated with existing forms that individuals will be forced to compete in peripheral niches, where novelties can be more favorably selected and further accumulation is likely. So for large-scale changes;

Total genotype fitness will decrease with major increases of genotype complexity (accumulation).
Because of this, individuals will first attempt fitness at the lowest level of genotype complexity.
Saturation of a complexity level forces individuals to compete for fitness in peripheral niches.
Peripheral niches will require lower comparative fitness levels, so significant accumulation will occur.
Accumulation occurs not to improve on previously attained genotype fitness, but because it provides greater genotype variability, in niches where very high genotype fitness is no longer attainable.

This mechanism of shallow accumulation until saturation, followed by rapid accumulation in peripheral niches as fitness falls gives a "stepped" effect of evolutionary accumulation.
(Note: Steven Gould's theory of punctuated equilibrium first emphasized stepped changes in large-scale evolution. But while the new theory borrows many concepts from punctuated equilibrium, the earlier theory failed to uncover that it was the loss of fitness over large accumulations causing the stepped affect.)

1.4 The Pattern of Evolution
The Theory of Large Changes applies to all evolving systems, but it was developed mainly to explain large changes in the history of life on Earth. These include the origin of major novelties such as sex, the causes of variability, stasis and rapid accumulation, origins of new species and phyla, plus the causes of human evolution and behavior. The argument is that in any evolving system, individuals will not just seek fitness, but seek it in a manner that minimizes the amount of genotype change, for the fitness to be gained. Yet how individuals seek fitness will have an ancillary effect of keeping the 'system' of evolution efficient as well. Fitness will force individuals to enact the easy-to-enact variations first, but only increase major complexity by singular concentrated efforts.
And while it not that simple, massive efforts to evolve new monophyletic attributes do "punctuate" evolution. Take the evolution of mammals. In conventional theory, we might suppose that a proto-species of mammal accumulated many fortuitous novelties as a part of its normal struggle for fitness. Later, a random event (asteroid strike, etc.) wiped out the rivals of mammals, so the now fully developed proto-species of mammal could opportunistically radiate into the newly vacated range. The new theory does not deny that these random events (asteroid strikes, continental drift, climate change) occur, and that many radiations are opportunistic (the right place at the right time). But when we find a tight integration of many new novelties over such a prolonged period there are too many coincidental events to explain. For example,

Proto-mammals accumulated not a few, but a huge variety of monophyletic attributes (four-chamber heart, body fur, live birth, diaphragm, endothermic regulation, efficient dentition, enlarged brain case, neo-cortex, milk to suckle young, etc.) within a single, or narrow range of species.
If every novelty evolved in a mammal is fortuitous, we must explain why no other creature evolved even one of these novelties, once ever, at any other time in evolution. (Birds have a form of endothermic regulation, but not the same).
If it were a fortuitous fitness advantage, we must explain why not even a simple novelty like body fur evolved elsewhere, even once, among the thousands of other species during the 140 million year Jurassic-Cretaceous period.

Also, while there were other radiations of proto-mammals during the Jurassic-Cretaceous, most branching lines went extinct. (Monotremes are descendents of a surviving line.) Generally, early novelties in primitive forms could not complete (some types, like monotremes, always finds a niche) until the larger set of attributes was perfected. Also, the first mammal radiation was of marsupials, preceding the evolution of the placenta. Only again, we must explain why the evolution of the placenta was monophyletic. If the placenta was also a fortuitous novelty, we must explain why no creature of any species on earth, not descended from a placental mammal, has ever been able to evolve a placenta since, or ever will. (We have to explain these events, but this does not prove that the new theory is the only viable alternative. We are just asserting that a "fortuitous" explanation of mammalian design is not sufficient.)
Moreover, even if we could explain every attribute of mammals, and each event of their evolution as fortuitous, we must then do the same for the evolution of reptiles, amphibians, fish or birds, and every large taxonomic group. Every major radiation of life on Earth has followed a similar pattern. (This is the assertion. If somebody knows differently, please point it out.) A set of not one, but several integrated monophyletic attributes has built up, often slowly, in just a single species or narrow range, despite a huge backdrop of evolutionary variety.

For the huge varieties of reptiles that existed, only two very narrow lines, or line of single proto-species, separately evolved into mammals and birds.
The proto-species of mammals did not radiate until it was a full mammal (with a few exceptions), or birds at a different time until it was a full bird (no exceptions).

There exists this same pattern of build up of and radiation for all the monophyletic attributes of life (cell tissue, nucleus, photosynthesis, skin, bone, jaws, coelum, vertebrae, nerves, etc.). There are exceptions, such that body segmentation occurred twice, or that the eye evolved several times. But we can show that eye is functionally polyphyletic anyway, but its evolution depends on deeper monophyletic attributes (like photoreceptor cells) present from a primal accumulation. Besides, eyes do not lead to radiations, even though we can be certain that an early creature with photoreceptor cells, did radiate the first time, as a single common ancestor of all creatures that now posses eyes.
Still, evolution is never that simple either. While complex types such as placental mammals radiated at a later stage in evolution than when less complex types such as dinosaurs radiated, ancestral species did not evolve in that temporal order. (Mammals, the more complex type, did not evolve from dinosaurs. They evolved in parallel with dinosaurs, both types descendent from a more primitive ancestor. See stepped changes.) And throughout evolution, branching into the lines leading to modern types was often in the deep past, so the order was not complex types evolving from simpler ones as a class. Rather, it appears that different primitive types set out on parallel lines of development, but simpler types reached a radiative maturity quicker, while complex types took longer evolutionary times to mature. (This infers that the "concentrated effort" to evolve new types occurred in parallel with a more dissipated effort to radiate simpler types, which also must be explained.)
The remainder of the theories will explain how all these effects occur.

New Model of Evolution

Theory of Complex Accumulations

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