Algoritmos evolutivos e o William Dembski (sim, outra vez)

Certo criacionista de trazer por casa, comentou que os algoritmos evolutivos não modelam (bem, ele utilizou o termo "provam", para ser mais exacta) "evolução cega", como ele tanto gosta de aventar, referenciando um artigo de um site criacionista, o qual se refere a um artigo do Dembski (e seus colaboradores), que, segundo eles, passou por revisão de pares (http://bio-complexity.org/ojs/index.php/main/article/view/50). O problema é que a "revista científica" na qual foi publicado é nada mais nada menos do que uma "revista" chamada "Bio-complexity", que é basicamente um website gerido por criacionistas, em que criacionistas publicam coisas revistas por outros criacionistas (tipo "Journal of Creation Research", mas com um nome mais bonitinho). Que eu saiba, ele (o criacionista) não é nenhum programador informático nem sequer biólogo (e muito menos isso!). Vamos ver, então, o que um verdadeiro programador tem a dizer sobre o assunto:

«There are several statements in the paper that suggests the authors have some fundamental misunderstandings of genetic algorithms and the observed phenomena on which they are based. As early as page 2, for example, is this:

The Darwinist claim is that no such assistance is required. Rather, natural selection is innately capable of solving any biological problem that it faces.

No “Darwinist” (a term that reflects ID’s creationist roots) claims this. Extinction is known to happen. [Verdade, verdadinha.]

Another, from page 4:

This genome is of a fixed length, always containing the coordinates and connections for the maximum number of interchanges. This simplifies the genetic algorithm because it not [sic] necessary to implement deletion or insertion mutations.

While the design of a GA engine is somewhat simplified by limiting genomes to a fixed length, such a constraint doesn’t prevent modeling insertions and deletions. Further, the lack of insertion and deletion mutations actually makes finding a solution more difficult by limiting the number of evolutionary mechanisms that can be brought to bear. 

[Num algoritmo genético, já muita coisa é simplificada - ver aqui um plausível exemplo: http://allthatmattersmaddy32b.blogspot.pt/2014/08/mais-baboseiras-do-william-dembski.html. Que mais é novidade?]

On page 5 we find:

Does the genetic algorithm have the ability to solve the problem given only a description of the same?

This question demonstrates a profound confusion about what is being modeled. The authors almost seem to be suggesting that they expect a GA to find a solution without any feedback whatsoever. That would certainly fail to reflect the biological situation.

In fact, the fitness function is a description of the problem domain, corresponding to the environment of biological evolution. In that sense a GA does have the ability to solve some types of problems “given only a description of the same.”» 

[Frases do texto original destacadas a negrito por mim.]

O autor do texto continua: 

«“Effect of count of interchanges”

The authors claim that having an explicit count of the number of non-fixed nodes in the virtual genome “shifts the distribution of solutions.” They also note that Thomas’s code ensures that a minimum number of non-fixed nodes (“interchanges”) are present.

My implementation contains no such explicit count nor does it specify any minimum number of non-fixed nodes, yet it routinely converges on an optimal or near-optimal solution.

“Effect of restricted initialization”

According to the authors, Thomas’s code restricts the initial location of non-fixed nodes to a smaller area than the full 1000×1000 grid allowed by the simulation. Again, my implementation has no such restriction and yet it routinely converges on an optimal or near-optimal solution.»

(http://theskepticalzone.com/wp/?p=735#more-735)

Está-me cá a parecer que mais uma vez os criacionistas só disseram asneiras (e mentiras). Que novidade!