Tree of life |
In this context, we must distinguish three
things:
- 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).
- 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.
- 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:
- Spontaneous
variations of the genome (mutations, genetic recombination and other
biological events that modify the genome).
- Spontaneous
variations of the environment.
- Natural selection, which guarantees that
individuals whose genome makes them adapt better to the environment will
leave more offspring (at least statistically).
- 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:
- Spontaneous
variations of individuals (mutations, recombination and other tools),
which usually apply pseudo-random algorithms.
- Spontaneous
variations of the environment, which usually also apply pseudo-random
algorithms.
- 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.
- 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
Thematic thread on Evolution: Preceding Next
Manuel Alfonseca
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