Look for a metaphysical development of whether something is possible. It doesn't have to be a certainty of existence and it doesn't have to have observational data to back it up if it isn't science.
Hi RightWhale! As to these allegations, let Meyer reply:
“Historical scientists, in particular, assess or test competing hypotheses by evaluating which hypothesis would, if true, provide the best explanation for some set of relevant data…. Those with greater explanatory power are typically judged to be better, more probably true, theories. Darwin … used this method of reasoning in defending his theory of universal common descent.”
[Do you suppose Charles Darwin was a closet metaphysician?]
Meyer details this point in a footnote:
“Theories in the historical sciences typically make claims about what happened in the past, or what happened in the past to cause particular events to occur…. For this reason, historical scientific theories are rarely tested by making predictions about what will occur under controlled laboratory conditions…. Instead, such theories are usually tested by comparing their explanatory power against that of their competitors with respect to already known facts. Even in the case in which historical theories make claims about past causes they usually do so on the basis of pre-existing knowledge of cause and effect relationships. Nevertheless, prediction may play a limited role in testing historical scientific theories since such theories may have implications as to what kind of evidence is likely to emerge in the future. For example, neo-Darwinism affirms that new functional sections of the genome arise by trial and error process of mutation and subsequent selection. For this reason, historically many neo-Darwinists expected or predicted that the large non-coding regions of the genome – so-called “junk DNA” – would lack function altogether…. On this line of thinking, the non-functional sections of the genome represent nature’s failed experiments that remain in the genome as a kind of artifact of past activity of the mutation and selection process. Advocates of the design hypothesis, on the other hand, would have predicted that non-coding regions of the genome might well reveal hidden functions, not only because design theorists do not think that new genetic information arises by trial and error process of mutation and selection, but also because designed systems are often functionally polyvalent. Even so, as new studies reveal more about the functions performed by the non-coding regions of the genome (Gibbs 203), the design hypothesis can no longer be said to make this claim in the form of a specifically future-oriented prediction. Instead, the design hypothesis might be said to gain confirmation or support from its ability to explain this now known evidence, albeit after the fact. Of course, neo-Darwinists might also amend their original prediction using various auxiliary hypotheses to explain away the presence of newly discovered functions in the non-coding regions of DNA. In both cases, considerations of ex post facto explanatory power re-emerge as central to assessing and testing competing historical theories.”
In short, “for historical scientists, ‘the present is the key to the past’”, and “present experience-based knowledge of cause and effect relationships guides the plausibility of proposed causes of past events.” This “experience-based knowledge” is not the simple product of laboratory experiments, for it reaches to issues of “plausibility” and “power of explanation,” which involve irremovable subjective judgments.
Yet here’s where the neo-Darwinist account of the origin of biological information may “objectively” be hoist on its own petard, on the basis of new discoveries in microbiology and information theory:
“…natural selection lacked any ability to generate novel information precisely because it can only act after new functional CSI (i.e., complex specified information) has arisen. Natural selection can favor new proteins, and genes, but only after they perform some function. The job of generating new functional genes, proteins, and systems of proteins therefore falls entirely to random mutations. Yet without functional criteria to guide a search through the space of possible sequences, random variation is probabilistically doomed. What is needed is not just a source of variation (i.e., the freedom to search a space of possibilities) or a mode of selection that can operate after the fact of a successful search, but instead a means of selection that (a) operates during a search – before success – and that (b) is guided by information about, or knowledge of, a functional target….
“The causal powers that natural selection lacks – almost by definition – are associated with the attributes of consciousness and rationality – with purposive intelligence…. Thus, by invoking design to explain the origin of new biological information, contemporary design theorists are not positing an arbitrary explanatory element unmotivated by a consideration of the evidence. Instead, they are positing an entity possessing precisely the attributes and causal powers that the phenomenon in question requires as a condition of its production and explanation.” Design theorists, in short, are concerned with the problem of the origin of biological information, and regard natural selection as patently insufficient in this regard. This insufficiency of natural selection “corresponds precisely to powers that agents are uniquely known to possess. Intelligent agents have foresight. Such agents can select functional goals before they exist. They can devise or select material means to accomplish those ends from among an array of possibilities and then actualize those goals in accord with a preconceived design plan or set of functional requirements. Rational agents can constrain combinatorial space with distant outcomes in mind.”
I’ve just culled some main points of Meyer’s article here. He provides ample supporting details in the text. His analysis of neo-Darwinism – and also of Kaufmann’s (et al.) self-organizational model, punctuated equilibrium, structuralism, and cladism – appears well supported by observational data and probability theory.
Whether you agree with him or not, Meyer’s article is a great survey of the current state of development in the main trends or approaches being taken to explore the subject of his title: “The origin of biological information and the higher taxonomic categories.” IMO FWIW.