Evolutionary theory has produced so many false predictions—and as a consequence has become so complex—that it is difficult to keep track. Evolutionists have approximated, truncated, contorted or whatever to obtain their mandated answer. The fact that evolution is a fact is underwritten by the rationalistic a priori constraint rather than the scientific results. The former has precedence because the latter is always a work in progress. Scientific results can change, so given enough time and contorting we may yet find that the science supports the rationalism.
In the meantime this commitment to method can lead to awkward moments, such as when the student asks how evolution created life and all its species, how it created such complexity, how it created such variation where it shouldn’t be, or how it created such similarity where it shouldn’t be, and so forth.
While brow-beating, intimidation, delegitimization, dismissal, mockery and funding threats are usually sufficient to check any such challenges, some evolutionists find safety in the ultimate defense: evolution’s latent anti realism. Scientific problems don’t matter because evolution need not track reality in the first place. It is simply a brute fact.
Descartes introduced the specter of anti realism to evolutionary thought in the seventeenth century when he advocated for naturalism regardless of truth. For when the true cause is unknown, “it suffices to imagine a cause which could produce the effect in question, even if it could have been produced by other causes and we do not know which is the true cause.” For Descartes, a theory could be fictional, but still useful.
Today, evolutionists dismiss scientific failure as inconsequential. Evolution need not produce true explanations, just useful explanations. The evolutionary tree has failed, for example, but as Joel Velasco explains, though evolutionary processes may not be tree-like, nonetheless the evolutionary tree model helps us to understand the world better:
Phylogenetic trees are meant to represent the genealogical history of life and apparently derive their justification from the existence of the tree of life and the fact that evolutionary processes are tree-like. However, there are a number of problems for these assumptions. Here it is argued that once we understand the important role that phylogenetic trees play as models which contain idealizations, we can accept these criticisms and deny the reality of the tree while justifying the continued use of trees in phylogenetic theory and preserving nearly all of what defenders of trees have called “the importance of tree-thinking.” …
We have seen that phylogenetic trees are ubiquitous in biology. The justification for the use of trees has traditionally been that evolutionary processes are in fact tree-like. This justification is faulty. Attempting to interpret phylogenetic trees in a literal way leads to the view that these trees entail many falsities about evolutionary history. Attacks on the universal tree of life thus appear to be justified. The goal of this paper is to argue that these attacks are not in conflict with the continued and justified use of trees and tree-thinking in biology. The use of phylogenetic trees can often be completely justified even if they are not entirely accurate representations of the world. Instead, these trees are models which contain idealizations. These models are used to better understand the world. Sometimes, for some purposes, a tree model is inappropriate. But often, trees are entirely appropriate and perhaps even the best models we have.
Modeling and idealizations are widespread throughout the sciences. There is no particular reason to think that systematics should be any different. Evolutionary history is complicated. It is a sign of the advancement of the science of systematics that we not only take advantage of standard modeling practices from other disciplines, but that we understand that this is what it is that we are doing. It is true that belief in the existence of the tree of life as the big, universal, grand unifying, scale-free representation of all of the history of life should probably go away (if indeed biologists ever did believe there was such a tree). Whether we can still talk about the tree of life as some modified version of this idea is, I think, an open question. Whether the problems with the universal tree extend to smaller trees as well will depend on the particular details of the case in question. But whatever the outcome of these debates, phylogenetic trees and the importance of tree-thinking are here to stay. The future of tree-thinking is bright as long as we can recognize the importance of tree-thinking without the tree.
Evolution’s predictions have consistently failed and the species do not form an evolutionary tree. These are yet more manifestations of evolution’s underlying anti realism. But evolution remains a fact.