Darwinism Intelligent Design News

Is chaos theory a problem for Darwin’s theory of evolution?

Spread the love

Probably, but what isn’t, these days?

See: Chaos and Unpredictability in Evolution

ABSTRACT: The possibility of complicated dynamic behaviour driven by non-linear feedbacks in dynamical systems has revolutionized science in the latter part of the last century. Yet despite examples of complicated frequency dynamics, the possibility of long-term evolutionary chaos is rarely considered. The concept of “survival of the fittest” is central to much evolutionary thinking and embodies a perspective of evolution as a directional optimization process exhibiting simple, predictable dynamics. This perspective is adequate for simple scenarios, when frequency-independent selection acts on scalar phenotypes. However, in most organisms many phenotypic properties combine in complicated ways to determine ecological interactions, and hence frequency-dependent selection. Therefore, it is natural to consider models for the evolutionary dynamics generated by frequency-dependent selection acting simultaneously on many different phenotypes. Here we show that complicated, chaotic dynamics of long-term evolutionary trajectories in phenotype space is very common in a large class of such models when the dimension of phenotype space is large, and when there are epistatic interactions between the phenotypic components. Our results suggest that the perspective of evolution as a process with simple, predictable dynamics covers only a small fragment of long-term evolution. Our analysis may also be the first systematic study of the occurrence of chaos in multidimensional and generally dissipative systems as a function of the dimensionality of phase space. (Colour added)

11 Replies to “Is chaos theory a problem for Darwin’s theory of evolution?

  1. 1
    Kantian Naturalist says:

    It’s certainly a problem for simplistic thinking about the theory — whether it’s a problem for the theory itself seems difficult to say.

  2. 2

    Absolutely not. It’s key.

    Non-linearity as a result of feedback is exactly what the Darwinian process generates, and the source, IMO, of the resulting exquisite complexity.

  3. 3

    It’s also, btw, the short rebuttal to the objection I used to see quite a lot by IDers that a simple cause can’t produce a complex result.

    Chaos theory simply shows that it can.

  4. 4
    Loghin says:

    So Dr. E a stochastic process is non-focal. It destroys the target’s fitness landscape. A linear process is what your theory predicts via gradualism. Your analysis of the fossil record claims just that. In order for a random search to yield complexity it has to follow incremental steps. You are undermining your premise.

  5. 5

    No, the Darwinian mechanism does not predict a linear process, and does not result in a linear process.

    It posits a feedback loop, and feedback loops result in non-linear relationships. Indeed, the proposed tree of life is a fractal.

  6. 6
    Loghin says:

    Dr.E, the fitness landscape is 2D in the simplified form (puttingt homology and homoplasty) in the same category. Since gradual changes are long the curves are either logarithmic or exponential.
    Reducibly complex systems are linear, that is if a+b+c=m than a+b+c+d=M+, where M+ is more complex than m. Evolution would thus be great at explaining the already observed changes in size for example.
    A loop is an irreducibly-complex feature, and thus a hallmark of intelligent design. Software maintenance routines and even Avida are designed in such a manner.
    Selection is not a proper feedback loop because any pozitive feature of the organism can be erased forever, while negative features in non-selected organisms are preserved.

  7. 7

    Loghin:

    Consider: Darwinian adaptive evolution will occur when a population of self-replicators replicate with heritable variation in reproductive success in the current environment.

    The population is what adapts, not the individual organism.

    It adapts in response to feedback from the environment. Not only that, but the environment changes in response to the activities of the population, and indeed the population itself is part of the environment in which the organisms have to survive and exploit.

    So the system is rich in feedback loops and powerfully non-linear. Consider, as a classic example, the Fegenbaum plot, which is a good model for a boom-bust population in an environment with limited resources.

    Not only that, but optimisation is non-linear – like many homeostatic systems, adaptation of a population to its environment asymptotes at an optimum which serves as an “attractor” – to which it may return when perturbed; or not. Perturbed beyond certain limits it may be “captured” by another attractor.

    In other words chaos theory is an extremely useful framework in which to consider evolutionary processes, and far from presenting a “problem” for Darwin’s theory, provides apt tools for modeling and understanding it.

  8. 8
    Alan Fox says:

    …the fitness landscape is 2D in the simplified form…

    Maybe some simplified models use only two variables for fitness but that is not reality. The niche environment that a population of organisms finds itself in is not so limited. Predators, prey, parasites, weather, climate, catastrophes, the list is endless and climate for instance is chaotic and unpredictable.

    ..pozitive feature of the organism can be erased forever, while negative features in non-selected organisms are preserved.

    There have been five maass extinctions during the history of life on Earth so countless species have disappeared that might otherwise have survived. Don’t know what you mean when you say “negative features in non-selected organisms are preserved”. Deleterious mutations will be eliminated from the gene pool if debilitating enough in the current niche.

  9. 9
    Loghin says:

    Here is the Kaynesian model ( ID) for development vs. an Austrian one (CD). Consider a population of individuals where each individual makes a rational decision regarding a certain aspect of their overall fitness. Such decisions are discrete variables (eg: number of eggs consumed on a daily basis). That behaviour on an aggregate basis would form a continous series. Variations within that continous series would appear to support the notion of evolution since that series would likely drift far from its original target. That is the flaw of the unguided fitness landscape. However in a designed system entities make predictions regarding their position and are able to reach the same fitness peak from unrelated points. Suppose we have classes of features and meta-classes which regulate those classes. If an adaptation procedes a modification within a fitness landscape then selection would no longer be necessary to explain that feature. You get chaos theory for an answer because you aggregate signals from multiple individuals, when a distributed approach (like in an ID’ed computer network would yield better results). Consider the variability of the inheritable traits expresed by Galapagos Finches.
    Beak sizes mutate in the offspring of the birds around a single range following unpredictable ENSO variability. Just one drop in the genetic diversity of the species and extinction will follow. Judging from the survival rate of the offspring the variation seems to do less with genetic drift ans selection but with a strategy. Another model is horizontal gene transfer by which beneficial parameters are shared across bacteria.
    The feedback loop proposed through selection is not an honest one since the model asumes that the organism does not alter the fitness landscape but rather follows it. Every individual alters its finess landscape. We can only look at animal technology in chimps, ravens and humans to observe it.
    Aggegated the signal looks chaotic but every component is ordered and planned. Good evening.

  10. 10
    TheisticEvolutionist says:

    As far as I know, Robert Wesson is the only author I have come across who advocated some sort of chaos theory to refute Neo-Darwinism.

    In this broad and highly readable inquiry, Robert Wesson proposes an approach to evolution that is more in harmony with modern science than Darwinism or neoDarwinism. He emphasizes the importance for evolution of inner direction and the self-organizing capacities of life, a view that is better able to account for the chaotic nature of the evolutionary process and the inherent propensity of complex dynamic systems to grow more complex with time. Many examples of plants and animals support this idea, and Wesson includes both carefully documented scientific facts and intriguing anecdotes about the odd aberrations in natural selection.

    http://mitpress.mit.edu/books/.....-selection

  11. 11
    Loghin says:

    So the problem with CDRM isn’t the lack of adaptations but the timing of said adaptations. I studied recursive filter systems as part of my disertation. In a typical filter the trasformation matrix is one. Changing the value could yield various output. In combination with various forecast techniques such a system could be used for predicting future fitness peaks. Thus the challange for ID is to find a version of this system in the genome and develop a mathematical model for it considering compression methods, filtering systems, epigenetics and non-quantized interactions between the various components of the genome.

Leave a Reply