How Transitional Forms are Identified Pt. 3

Maybe, in the fossil record, we can look for patterns. Let’s look at our hypothetical chain of interbreeding. Species P can interbreed with species D1, which can interbreed with D2, which can interbreed with D3. While physical similarities themselves may not be a reliable indicator of relatedness, closely related organisms will look similar to each other. So, P will look the most like D1, D1 will be similar to P and D2, D2 will be similar to D1 and D3, and D3 will be most similar to D2. So while we may not be able to find an interbreeding chain in the fossil record, if an interbreeding chain were to exist, there will be a progressive chain of similarities from the parent species to the final daughter species.

There are a few considerations that need to be taking into account at this point. First of all, while a progressive chain of similarities implies that there is progress being made, and thus, the parent species would be primitive while the daughter species would be more advanced, modern evolutionary theory does not accept the ideas of primitive and advanced. Evolutionists don’t like these terms because it implies that later descendants are necessarily better than their ancestors. So the terms ancestral and derived are used. Ancestral condition simply means whatever features the parent species had while derived simply refers to new features that the daughter species have. The terms ancestral and derived are used because there are no connotations of “worse” or “better” associated with them. Still, the concept of a progressive chain of similarities is valid, since a chain of interbreeding would start with ancestral conditions in the parent species with more and more derived characters (a progression of new characters) arising in the daughter species.

The second thing to consider is what this progressive chain of similarities would look like in terms of side branches. If you look at a cladogram, which is a chart purporting to show the heritage of a group of organisms, the chart branches off repeatedly. It may appear at first that there is no linear progression. Rather, everything appears to be a complicated web or bush. However, despite all of the branches, a single, linear progression can be picked out. If you start with the common ancestor (which would exist at the base of the cladogram) and then pick one of the final species as your target daughter species, you will be able to traces a single path from the common ancestor to the final daughter species. Many side branches will have been passed by, but if these are ignored and you focus on just the line of descent from the common ancestor to your chosen daughter species, a single, linear progression can be traced. So while there may be a multitude of side branches and transitional forms for other lines of descent muddling up the picture, a single progressive chain of similarities can be found.

The last thing to consider is how this progressive chain of similarities will relate to time. Time in the fossil record is about as controversial, as far as the theory of evolution verses creation science goes, as whether or not transitional forms exist. In the theory of evolution, the fossil record represents a huge amount of time and each layer of rock represents sediments that were accumulated over a long time period. In creation science, the majority of the fossil record is thought to have been laid down by the worldwide deluge (Noah’s flood), which lasted about a year. So the fossil record represents a very short amount of time (compared to the evolutionary view). However, since transitional forms would exist only if the theory of evolution where true, we will have to consider how the progressive chain of similarities would look in the fossil record assuming that the fossil record represents a long period of time.

Obviously, you can not have the descendant before you have the ancestor. That would be like saying that the son is older than the father. So the first thing to note about the chronological progression of a progressive chain of similarities is that the ancestor should be the oldest, and the descendant should be younger. This does not mean that the ancestor and descendants must exist at different times: it is very possible that the ancestor may exist alongside its descendants for a time. For instance, if species P were in existence, then it gave rise to species D1, species P need not necessarily go exist: species P may persist for a time after it gave rise to species D1. Matter of fact, it is even theoretically possible that species P may remain in existence long enough that is descendent, species D1, actually goes extinct before it does. So we can not look for when an ancestral or a descendent species lived, we have to look for the first occurrence of each species, since that will tell which was first in existence.

What about the reverse? If species P and species D1 may be coexistent for a time, what are we to do about instance where the earliest specimen of the supposed parent species is found in rocks that are younger than, or of the same age as, its descendent? Since the fossil record is incomplete, it is possible that the first occurrence of the parent species is missing, or has not been found yet. While it is theoretically possible that the daughter species may be found in rocks that are older than the parent species, we must remember what we are looking for: we are looking for evidence of transitional forms. Thus, only when the parent species is found in rocks older than the daughter species will there be any actual evidence for transitional forms, since that fits the anticipated pattern. While the reverse pattern (parent younger than species in the fossil record) can be accounted for, that will not provide evidence that the two species in question actually form a chain of interbreeding. Rather, that would be fitting the data to the theory. We want to test the theories and see which one already fits the data.

The last thing to consider about a chain of similarities is, how much of a difference is acceptable between each link in the chain? For instance, if we were looking for the transitional forms between a reptile and a bird, would the sudden appearance of feathers be an acceptable jump from one species to the next, or would we expect to see more gradual changes? In the case of feathers, we would expect to see more gradual changes. It would be difficult to put an exact limit on how dissimilar two species can be before the gap between them is considered to be too large to be reasonably explained as an evolutionary jump. Certainly, the measure of change will be different between an evolutionist and a creationist. The evolutionist might consider the presence of legs on a whale as evidence that it is a transitional form while a creationist might question, so where is the whale with half-legs, half-flippers? In this point, the burden of proof is on the theory of evolution. It claims that transitional forms must be there, and it claims that the evolutionary process occurs in increments (even punctuated equilibrium must occur in increments: the rapid jumps are not the sudden acquisition of brand new features, they are the rapid accumulation of minor changes in a short amount of time). In the theory of evolution, the chain of interbreeding must have existed at some point. Whatever differences exist between two species in a chain of interbreeding, they are not enough to prevent the species from interbreeding. That fine of a scale must also be applied to the chain of similarities: the differences between adjacent species on that chain must be slight enough that they could almost be mistaken for the same species.

Evolutionists may complain at this point, saying that I am relying on the absence of evidence to prove that there are no transitional forms. This is not the case. Rather, I am saying that the theory of evolution can not be excused with the absence of expected transitional forms. Small differences in physical appearance can not be extrapolated into tiny differences in physical appearance without any evidence that such an extrapolation is valid. To say, “Species A is very similar to species C, so we may assume from the progression from A to C that a species B must also have existed” does not lend credence to the idea that transitional forms exist. Rather, such an extrapolation is based on the assumption that transitional forms must exist.

Granted, searching for tiny increments in the chain of similarities is by far the hardest proof needed to demonstrate that transitional forms exist. But that is what the theory of evolution predicts so if the theory of evolution is true, then such a chain must be shown to exist, otherwise known species will just be placed in an order so as to fit the theory.

Here is the final score then: transitional forms can not be identified by physical similarities, as it is acknowledged by both evolutionists and creationists that there are instances where physical similarities do not indicated relationship. Cladograms do not constitute proof of transitional forms, as they are constructed with the assumption that transitional forms exist. The only definitive proof of transitional forms would be a chain of interbreeding, where the parent species can interbreed with the first daughter species, and the first daughter species can interbreed with the second daughter species, but the second daughter species can not interbreed with the parent species. There are no known chains of interbreeding in living organisms, rather there are groups of interbreeding organisms, which is consistent with creation science. The last place to look for chains of interbreeding is in the fossil record. Since only physical similarities can be drawn out of the fossil record, physical similarities will have to be used in conjunction with other features. The chain of interbreeding would appear as a chain of similarities, with the parent species most similar to the first daughter, the first daughter more like the second, and so on. These species would have to appear in the proper chronological order. Lastly, the differences between adjacent species in the chain of similarities must be tiny: the chain should show small, incremental changes, rather than broad jumps.

The preceding criteria can be applied to species that are claimed to be transitional forms, to see if that claim is valid or whether the claim was made in order to fit the data into the theory of evolution.