Transitional Intermediates — In Fossils or Life Forms Today
- What is a transitional form? (what would one look like ... either as a fossil or as a living example)
- Does it seem ludicrous to expect that there should be living examples of transitional intermediate life forms today?
- How many such 'living transition forms' should we be seeing today to know that these are truly telltale signs of ongoing evolution?
- Shouldn't we find literally thousands of new variations at any one time?
- Is there somewhere a new and novel organ in the midst of evolution?
- Why would this (the presence of intermediates) have only happened before but not now?
- Why do features like feathers appear abruptly in the fossil record with hardly any notion of a precursor?
- We seem so embarrassed to ask the obvious questions, but why not ask... where are the intermediates in the fossil record and why are their counterparts so hard to see in life today?
We really need to visualize what these questions imply in terms of seeing evidence for change in form and structure (internal and external) over time. This after all goes to the heart of the standard evolution story. Indeed, as noted elsewhere in the window's view we see a progression of life forms, even series of similar species, but now we are looking within the progression and closer at what is required to make the standard story work. For those who assume intermediates fill gaps in the evolution story, a 'double-take' look is needed. The sobering notion here is that perhaps the gaps are not being filled and may never be filled.
Within the standard approach, one expects an earlier life form's morphology to change, for example, with bone and muscle transformations over time (e.g., animal), but remember, too, organs and other internal features at the cell and tissue levels are also thought to evolve as well (for all life ... even for plants as well as animals). And the theory implies these changes occur in stages or steps for all such transformations over time. What we are asking is: Is there evidence for these (numerous partial) stages? If not, then where is evolution theory?
The short answer is ... there is a problem for the theory because the evidence is not easy or is impossible to find. If fossils are relatively abundant (in locations where they are easy to find), then shouldn't there be at least some degree of evidence for intermediates? If evolution works this way, then why not see numerous living intermediates leading from accepted species to unique forms beyond that species?
Yes, there should be more and more evidence (in the fossil record especially), but no it's not clearly there. Typically, science press releases indicate new fossil finds often result in identification of new species. If intermediates were the common discovery, there would be by now numerous such releases announcing evidence for evolution's persistent progression along their branches of the tree of life.] Either someday the evidence will be found, or simply put, there is no such evidence and so as long as there are scientists to insist on asking the question ... we will forever be left with a mystery as well as the insistence that the evidence will one day be forthcoming. Closing the door on a possibility seems a bit too final ... and that in itself takes us to other conclusions. But given what else we've explored in the WindowView,having no intermediates may not be so surprising ... it may be consistent with an approach other than what evolution theory concludes. We are not denying fossil evidence or the appearance of progression, but we are also not expecting more than what the data reveal. We are not reading anything into the standing evidence.
So, yes, there are variations in living forms today, but much of the variation leads to differences within species or closely allied groups (e.g. within genera). To get beyond closely related species, as evolution theory would have it, we might picture fluid change over time. It is this type of videographic representation that we see in conceptual presentations on television that depict evolution theory. And fossil bones, scales, leaf impressions, casts, etc. reveal shades of variation, but one needs to consider if this again is variation within closely allied species. Ultimately, the distinct multiple intermediate steps from one species to an entirely different type of organism are lacking!
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The topic at hand may seem a bit tricky. We see today more and more scientists making the claim that they have found evidence for intermediates. Indeed interesting new evidence for different life forms keeps on coming. The critical element here is to discern new species that by many of their similar traits fit between known species as opposed to intermediates that truly lead along the branches of the evolutionary tree. And this is something touched on in the companion article on lineage. No intermediates, no branches, and thus no reason to construct the classical picture as a tree of life. Chopping the tree up into segments leaves us—at least according to one approach to classification of life—with the hierarchical or typological schemes discussed previously (see related article).
Here we briefly address the issue of intermediates. Reading related articles (see links above) rounds our a larger picture on this topic. The following quotations help to characterize and summarize this as a long standing issue. And in light of other new evidence, for example on design and complexity of life, the issue of the absence of intermediates becomes overshadowed by new discussions leading to more definitive conclusions. Yet, the issue of intermediates and the lack thereof was not lost even to Darwin:
There is no doubt that as far as his macroevolutionary claims were concerned Darwin's central problem in the Origin lay in the fact that he had absolutely no direct empirical evidence in the existence of clear-cut intermediates that evolution on a major scale had ever occurred and that any of the major divisions of nature had been crossed gradually through a sequence of transitional forms. Over and over, he returns to the same problem, confessing that:
... the distinctness of specific forms and their not being a blended together by innumerable transitional links is a very obvious difficulty
...This was particularly true of various highly specialized organisms and organs, and Darwin concedes:
Is it is no doubt difficult even to conjecture by what gradations many structures have been perfected ...
... although in many cases it has most difficult even to conjecture by what transitions organs have arrived at their present state ... Denton (ETC) Page 56
Evolution theory was virtually a nonstarter as a viable proposition without evidence for an array of forms revealing the continuous progression from distinct species to yet other types of varied life form. And as we are reminded, Darwin's theory was not the only topic under discussion.
... Without intermediates, not only was he unable to prove decisively that organisms had indeed evolved gradually as a result of simple random processes such as natural selection, but he had no way of distinguishing empirically between his own evolutionary model of nature and its non-evolutionary rivals, whether they were basically naturalistic, postulating a sudden but natural macromutations as a basic mode of change, or frankly supernatural, invoking the intervention of God.
The challenge to his evolutionary framework was underlined by the fact that the only explanation Darwin was able to offer in the Origin was his appeal to is the 'extreme imperfection' of the fossil record. But this was largely a circular argument because the only significant evidence he was able to provide for its 'extreme imperfection' was the very absence of the intermediates that he sought to explain. Denton (ETC) Page 57
In fact, there has been something of a historic cover-up from within science. A major fossil find made by Charles Dolittle Walcott in the Burgess shale formation in British Columbia—something he discovered in 1909—went virtually unreported to the scientific community for most of the twentieth century. Herein was evidence supporting one of the most explosive periods of life's appearance on earth. This fossil information is also similar to recent discoveries made in China ... all of which goes to something we know today as evidence for the 'Cambrian explosion' or 'biology's big bang.' These collections of fossils from Canada and China are quite extensive and here again should provide an excellent opportunity to find intermediates ...
... yet none of them turned out to be links between previously unknown phyla, only ten hitherto unknown and presumably peripheral twigs of the tree of life. As Morris and Wittington comment:
"Perhaps the most intriguing problem presented by the Burgess Shale fauna is the 10 or more invertebrate genera that so far have defied all efforts to link them with known phyla. They appear to be the only known representatives of phyla whose existence had not even been suspected. " Denton (ETC) Page 161
The apparent lack of intermediate forms has lead to other suggestions. One being the concept that life makes jumps in what is called punctuated evolution. The explanation can only stand as a place holder for there is little explain how the jumps leading to rapid appearances of new life forms can occur.
As noted elsewhere in our explorations, the information required to produce any difference in life forms needs information to be present or in some way information added to the system. To have a coordinated jump in morphology, anatomical features, different physiologies, etc., takes a large amount of information (remember the jump is rapid and in geological time is 'instantaneous'). But are these jumps also associated with life's imperfect attempts at forms that fail to survive? The fossil record appears capable of revealing the sudden appearance of multiple phyla, but beyond that we are hard pressed to determine if there were numerous failed lines stemming from some type of failed trials made at the start.
Going in yet another step—to make a point concerning the random or natural process behind evolution also provides—we can encounter discussions that entertain what appear to be examples of imperfect results by way of the evolutionary process. Now our attention shifts from a lack of intermediates, to jumps in form, and to evolution's proof by way of imperfect results. So, we need to think this over, too.
Near-optimum form is often thought to be equally predictable from the always-perfecting process of natural selection and the optimum design of an intelligent Creator. Stephen Jay Gould, on the other hand, has suggested that the theories are distinguishable by imperfections. As he reasons, the evolutionary process, being blind to purpose, limited in resources and constrained by history, might be expected to produce less-than-optimal designs.
Gould's showcase example is the panda, which, because of the constraints of being descended from five-fingered bears, lacks an opposable thumb. Yet the inefficient, blind process of evolution provided the panda with a "second-best" solution: an extension of the radial sesamoid bone in the wrist which can function as and immovable "thumb." This thumb is used by the panda to strip of leaves off bamboo shoots for food. Such a less-than-optimal design is evidence, Gould claims, for evolution and not intelligent design. Wise (CH) Page 221
So, given the panda's thumb as one example, how does Dr. Wise respond to Dr. Gould's suggestion?
There are at least two reasons to doubt that suboptimal improvisations are truly suboptimal. First of all, we are far from understanding the complexity of individual organisms, let alone the entire ecosystem in which that organism lives. What appears to be less than optimal design to us with our limited knowledge may actually be an optimal design when the entire system is considered. Wise (CH) Page 221
In the case of the panda, it's not clear that an opposable thumb would be any better design than its current wrist-bone extension.
Second, all claimed suboptimal improvisations seem to work efficiently enough. The thumb of the panda, for example, seems quite efficient at stripping bamboo leaves. In fact, according to evolutionary history, the panda's thumb has probably provided food for the panda for millions of years. Of the fact that the panda is now endangered seems to be due to dwindling food reserves and the encroachment of human beings—neither of which is likely to have been prevented if the panda had had an opposable thumb. Wise (CH) Page 222
Again, we note the present discussion is going to be brief. There are other examples like the one above. We mention Dr. Wise's response because the panda's thumb example is often presented without counterpoint. The idea of the window's view is to look at more than one perspective and this example now has two perspectives to consider!
Are there still other issues to examine on what might be considered suboptimal or imperfections due to evolution's process? One other quick example is that of vestigial organs or structures.
What is a vestigial organ and how might we think of such structures today? Or, conversely, are vestigial organs remnants and thus nonfunctional, or might these structures remain with purpose!
... organismal structures probably linger with reduced function for long periods of time before finally disappearing. These organs with reduced or no function are called vestigial.
Although many organs once thought vestigial have been found to have a function, others are sure to have at least a reduced function from the past (e.g., hip bones that appear briefly in the embryology of sperm whales and small appendage bones that are found in some snakes). These then are less-than-optimal organs that would seem to be evidence of evolution rather than intelligent design.
A serious problem with this argument for evolution is that whereas this vestigial organs are known, nascent organs are not. If evolution were true, one would expect to see not just organs "going out" but also organs "coming in." These new organs would be called nascent organs. The absence of such organs would seem to argue that although we have evidence of a degeneration from an earlier, the more optimal design, we lack evidence of a move toward a new optimal design. It would seem that if an intelligent Designer created optimal designs in the past and life's history has been a move away from that optimum, the presence of vestigial organs and the absence of nascent organs would be better explained by intelligent design than by evolutionary theory. Wise (CH) Page 222
Dr. Wise provides counterpoint along the lines inclusive of a view supported by 'intelligent design.' Overall, the window view is being examined to make a single point, and that is life embodies evidence supporting purpose beyond some brute reality without purpose. Design and the research to generate data that demonstrate the presence of design is considered in yet another article here on that very topic. But note the added perspective Wise gives us about organs that seem on the way out ... where then is the question of organs coming in? That's an added perspective to put in the view. It's the type of question that begs a double take ... a second look. Once that hits your attention, you may find yourself asking questions beyond the surface of any issue you examine. And that is the nature of perspective building and finally one's ability to realize that life does embody evidence for something special! Even science helps in this revelation! Indeed, why not? After all, science is not a person's opinion but a process of gathering evidence. Let's see where the data take us!
If the exceptionally limited presence or apparent total absence of fossil intermediates were the only issue to consider, then our look at origins would be a narrow view. This issue is teased out of the view, here, as a reminder. The scientific community is trying very hard to say intermediates can be found all over. But if we step back to look at exactly what the evidence reveals ... it's clear we are see some reports stretching the data and leaning on assumptions folded into interpretations. The findings thus far are far short of what could clearly be a broader field of evidence in support of the standard story. And if we look through the broader field of view across the horizon of all the issues to be observed within the window ... then the lack of intermediates only need lean away from the standard conclusions... for it's the broader view in total that has us walking in completely a new direction ... to new research, to new questions... beyond the standard assumptions. The the conclusions may be different from the standard but this makes our look at origins a time for some excitement ... for something special resides in time thinking, looking, and discerning what is evident ... even from the investigations and results stemming from the scientific community itself!
Quotations from Dr. Michael Denton's "Evolution: A Theory in Crisis" are used by permission of Adler and Adler Publishers Inc., 5530 Wisconsin Ave, Suite 1460, Chevy Chase, MD 20815
Quotations from "The Creation Hypothesis" (CH) edited by J. P. Moreland are used by permission of InterVarsity Press, P.O. Box 1400, Downers Grove, IL 60515. www.ivpress.com All rights reserved. No portion of this material may be used without permission from InterVarsity Press.
Writer / Editor: Dr. T. Peterson, Director, WindowView.org