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Many examples have been put forward as instances that bridge the gaps between extant or fossil taxa. Before we give consideration to any of these we should back up to evaluate the philosophical question of origins and gaps.

No knowledgeable person would question the widespread and pervasive nature of gaps between taxa, modern or fossil. This is the norm. To propose a fossil or extant form to be an evolutionary intermediate between two fossil or modern taxa, one should first establish the criteria that would enable one to recognize the form as intermediate. What characteristics should a valid evolutionary intermediate exhibit before we can consider it to be a true transitional form between two disjunct taxa?

1. If "A" is a taxon presumed to be ancestral, and "C" is a taxon believed to be derived, then "A" and "C" should differ from one another only with respect to the characteristics in which "B" is intermediate. If "A" and "C" exhibit other differences that are not represented in "B", then one should look elsewhere for an intermediate.

One could always argue that the resolving power of the fossil record is inadequate for the preservation of every intermediate between two end forms. But if that is true, we must abandon the certainty that all-too-often attends the assertion that any particular form is a true evolutionary intermediate.

If we limit our consideration to only a particular condition (i.e. length of tail, or some other measurable trait) and ignore other features, we can never make the assertion that the condition is intermediate. It may be an example of parallel evolution or in some other relationship to the derived form, rather than in a direct lineage.

When we attempt to include all characteristics in any consideration of intermediates (cladistic analysis), we end up with some conditions that are appearing in the right order (the ones evolutionists traditionally would concentrate on), and a suite of other conditions, some of which are ancestral, and some of which are derived, and some of which appear not to fit any evolutionary lineage. Although the cladistic approach is often said to support evolution, such an assertion is tautologic, since cladistic analysis depends upon evolutionary assumptions in its constructions. Evolutionary cladists (there are some cladists who refuse to assume evolutionary relationships as a premise) are forced to invoke the "principle" of "parsimony" (choosing the path with the least number of falsifying characteristics) in order to maintain their evolutionary view of relationships. But these are hardly the attributes one would wish to push as evidence for intermediate status.

2. If "A" is found earlier in the fossil record than "C", and "B" is intermediate, then the stratigraphic criteria for "B" as an intermediate are satisfied. If "B" is found either earlier than or at the same time as "A" or later than or at the same time as "C", the intermediate status of "B" is compromised.

If a fossil form meets these two criteria, namely intermediate characteristics and intermediate stratigraphic position, it would seem to represent a plausible intermediate form.

Unfortunately, few if any fossil forms meet these criteria for intermediates. Thus evolutionists who wish to represent forms as intermediates are forced to invoke other criteria for their claims. Unfortunately, as a result, the concept of an evolutionary intermediate has degenerated to include any creature having any features deemed intermediate between posited ancestral and derived forms, that occurs at an appropriate stratigraphic interval between "A" and "C". It is also used to refer to stratigraphically intermediate forms which share any features with "A" and "C", and of course the more features they share, the better. Sometimes creatures that are NOT stratigraphically intermediate are also branded as intermediate. In these cases it is assumed that they must have been, and that the evidence has just not come in yet. However, is it really useful to debate whether any given proposed intermediate is really an intermediate or not? The problem of gaps in the fossil record is really a much broader problem for evolutionists. Rather the crucial question is: When we evaluate the fossil record as a whole, disallowing evolutionary bias, does it look the way it should if the evolutionary explanation is the correct one? Here, one would want to concentrate on the records that are most complete, such as the fossil record of marine invertebrates. In this case, even using the most liberal assumptions about what constitutes an intermediate, evolution, as an explanation for the hard data, comes down, failing to explain the observed stratigraphic patterns in these most complete fossil sequences. The fossil record remains a record of gaps between recognizable taxa that will not be palliated by further exploration, and will not be bridged by the proposal of new intermediate forms, regardless of what the criteria are for proposing an intermediate.

______________________________________________________ Ó 2010 Arthur V. Chadwick, Ph.D.