Thursday, January 25, 2018

Chance or design?

Tree of life
In this context, we must distinguish three things:
  1. The scientific theory of evolution, which is strongly supported by data from other sciences, such as embryology, comparative anatomy, paleontology, biogeography, or molecular biology (DNA analysis).
  2. The claim that evolution is a consequence of pure chance, which is not a scientific theory, but philosophical, although its supporters claim that it is scientific.
  3. The assertion that evolution is an example of design, which is not a scientific theory either, but philosophical. The supporters of intelligent design argue that it is scientific.
To solve this dilemma we would have to answer one of the following questions:
         Is there a way to prove scientifically that evolution is a consequence of chance, rather than design?
         Is there a way to prove scientifically that evolution is a consequence of design, rather than chance?

First of all, I am proposing here a similar situation where we do have all the data.
As I have mentioned on other occasions, in my work in the field of artificial life (computer programs that simulate living organisms and their behavior) certain tools are used (evolutionary algorithms) that are inspired by biological evolution. Let us see how.
The theory of evolution, in its current form, states that the transformation of species (the evolution of life) depends on four factors:
  1. Spontaneous variations of the genome (mutations, genetic recombination and other biological events that modify the genome).
  2. Spontaneous variations of the environment.
  3. Natural selection, which guarantees that individuals whose genome makes them adapt better to the environment will leave more offspring (at least statistically).
  4. The basic laws of the universe, currently represented by quantum theory and the theory of relativity.
The first two factors are what Jacques Monod called chance in his book Chance and necessity. The third (natural selection) corresponds to necessity. The fourth factor is not usually mentioned, but has lately reached more importance, when it was discovered that the laws of the universe seem to be finely tuned to make life and its evolution possible.
Evolutionary algorithms, on the other hand, are based on the following four factors:
  1. Spontaneous variations of individuals (mutations, recombination and other tools), which usually apply pseudo-random algorithms.
  2. Spontaneous variations of the environment, which usually also apply pseudo-random algorithms.
  3. A fitness function, which measures the adaptation to the environment of each individual, and a selection program that guarantees that the most adapted individuals will leave more offspring or just pass on to the next generation.
  4. The basic laws of the system, which are very varied. In the case of the Tierra program, for example, designed by Thomas S. Ray a quarter of a century ago, these laws consist of the instructions of a programming language, similar to the machine language of a computer, which make it possible for simulated individuals (small programs that run in a virtual machine) to reproduce and compete for resources (the available memory).
Tierra computer simulation
It will be noted that the structure of artificial life programs is inspired by biological evolution. With these programs one gets amazing results. With Tierra, for instance, after a number of generations, parasite programs appeared spontaneously, which take advantage of other individuals to reproduce; then anti-parasitic programs appeared, which prevent the parasites from using them to reproduce.
I propose a mental experiment: suppose that in the very distant future, after a few billions of generations, intelligent beings could emerge in programs of this type. If these beings analyzed their world, they would have enough data to reach the conclusion that their existence was the result of evolution. Would they think that this evolution was a consequence of chance, rather than design? However, every artificial life program is a clear example of design. Tierra was designed by Thomas Ray, my experiments were designed by me. If our future hypothetical intelligent entities were to apply the philosophical theory that their evolution was a consequence of pure chance, they would conclude that neither Ray nor I do exist. And they would be wrong.
Or would they be able to detect that the chance that originated them was not really random, but pseudo-random? In that case, perhaps they could prove scientifically that they had arisen as a result of intelligent design.
Would they be able to prove it? You can find the answer in the next post in this series.

The same post in Spanish
Manuel Alfonseca

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