Fossils — The Appearance of Life
Questions:
- Do fossils tell us something incredible about life's origins?
- Is there a preponderance of fossil evidence saying evolution is a fact?
- What was the thinking concerning fossil evidence in Darwin's day?
- What can be learned today from the Cambrian era and the 'biological explosion' of life at that time?
- Was the Cambrian the only 'explosion' to life's origins?
Short Answer:
Today's fossil evidence comes from many continents and is as complete as can be expected. New finds will yet occur, but massive global collections have been acquired since Darwin's time. If the current trend holds, new fossils will either confirm types already discovered or forms that are new distinct species. Rare evidence for apparent intermediate forms surfaces from time to time, but just as often, upon close examination, do not fit a logical time sequence, prove to be unique species, or are the exceptional rare cases fitting between other distinct species. To work, naturalism requires a multitude of intermediate forms bearing signs of still as yet incomplete features or unformed traits. The large number of such transitions are absent and so too is the support that Darwin, and others, expected.
There is equally strong evidence for life forms appearing as types that are uniquely distinct without ties to a common ancestor or a 'tree of life.' Fossil evidence can as easily fit hierarchical patterns without the tree. But further still, there is evidence for a rapid appearance of life, such as with the Cambrian explosion, where numerous unique body plans arise over several million years.
Some scientists speculate all early animal forms arose from sponges ... the jump from a [simple but highly] unique life form to body plans with ever more complex tissues and organs demands a competent explanation. Even sponges exhibit coordination of cell tasks and internal complexities. So, are they really all that primitive! And the Cambrian explosion is not the only 'event horizon' for the rapid appearance of new forms.
Note: With regard to the sponge example above. The role as an evolutionary ancestral form is suggested by a recent episode of 'Shape of Life,' a television series, produced by the National Geographic Society and presented with the title of "Origins / Life on the Move" (PBS television; Spring 2002). From a sponge, we are told in sweeping language, all of evolution can be worked out. This in part is based on genetic research and findings for a single gene. The conclusions are incomplete and unjustified. But to the uninitiated viewer the message is clearly misleading. If anything, the show reveals how a simple organism like a sponge is in fact not so simple and quite specialized. There is little further evidence to show how one goes from a sponge to the multiple body plans observed for the Cambrian era.
Fossils have not closed the Darwinian gap. They tell a different story. Appearances of features such as a feather come all at once and fully unique to the task of aerodynamic flight. Even the hint of evidence that dinosaurs had feathers does nothing to answer questions concerning presumed transitions. Fossils tell us phyla (i.e., with unique body types) come suddenly. The same message applies for early life, first with microbes on a young earth (ca. 3.9 billion years ago), then for animals and later for plants.
Once in existence, organisms that leave fossils provide evidence for stasis—that is organisms conserve their form. They don't exhibit change as expected by evolutionists. Form and features stay with phyla (indeed even with appearances of new species within these hierarchical groups).
Mass extinctions are also followed by appearances of life but without long periods of time for redeveloping life's many types from scratch. The data are not there to seal evolution's dominion. There is no such closure based on fossil evidence.
"The facts in favor of evolution are often held to be incontrovertible; ... Those facts, however, have been rather less forthcoming than evolutionary biologists might have hoped. If life progressed by an accumulation of small changes, as they say it has, the fossil record should reflect its flow, the dead stacked up in barely separated strata. But for well over 150 years, the dead have been remarkably diffident about confirming Darwin's theory. Their bones lie suspended in the sands of time--theromorphs and therapsids and things that must have gibbered and then squeaked; but there are gaps in the graveyard, places where there should be intermediate forms but where there is nothing whatsoever instead."
-- David Berlinski, The Deniable Darwin & Other Essays, pg 42
Consider This :
Fossils helped evolutionists and taxonomists to suggest initial schemes showing how life might fit a sequential order. That order appears to form a continuum. This, as Darwin surmised, would one day be the conclusive proof for evolution—if in fact evolution theory were correct. And it was obvious to Darwin, and others in his day, that evidence for the all important transitional intermediates was lacking. These forms were necessary to make the continuum a reality. Without these the theory appeared flawed.
See
our related article
and illustrations: Cambrian
Era -
A Graphic Overview
From Darwin on, a search for evidence was not only limited to the geological strata and ancient remains, but also to present day forms that in living form reflect ancient natural history. Let's first look at the idea of gathering evidence from present life forms (extant life; living fossils so to speak) and later consider ancient fossil evidence (extinct; past life; including remains as bones or fossil impressions left in coal, stone, or other materials) ...
In the decades immediately following the publication of The Origin it was widely believed that eventually the missing links would be found in the theory of evolution confirmed. Hence the search for them became something of an obsession; word of new fossil discoveries was greeted with considerable excitement. ... What particularly caught the imagination of biologists, and the general public, was the prospect of finding "living links" in unexplored regions of the globe. Denton (ETC) Page 158
LIVING FOSSILS
Examples of living fossils include the horseshoe crab and lungfish. Dr. Denton provides an interesting discussion concerning the lungfish in Chapter 5 of 'Evolution' (ETC). Here the living form reveals something that the typical (skeletal, bony) fossil cannot show us. The living fossils' internal organs (which are a full compliment of otherwise absent features in a typical fossil) can be considered with respect to the earliest members of the same species. Lungfish and other examples, as explained by Denton, appear to reveal a combination of traits (mosaics) that help little to identify these organisms as intermediate forms and that gaps between groups remain due to the 'living data' that compliments the ancient fossil finds.
THEY DON"T SHOW CHANGE
The real question might not be living fossils prove evolution, but instead reveal evidence for fixity of type ... stasis ... that is, a lack of change over time. What then of natural selection, mutations, chance, and random variation for any species that appears now not to have changed or to have changed very little?
A number of deep sea fish species and many invertebrates, both terrestrial and aquatic, have been discovered over the past century but all of them have been very closely related to already known groups, and in the few exceptional cases, when a quite a new group of organisms has been discovered, it has invariably proved to be isolated and distinct and in no sense intermediate or ancestral in the manner required by evolution. Denton (ETC) Page 159
Science Believers Keep Looking ... Hoping
From Darwin's time to the present, there's been an ever increasing and ongoing effort to find missing links!
So fast has been the expansion of the paleontological activity over the past one hundred years that possibly 99.9% of all paleontological work has been carried out since 1860. Only a small fraction of the hundred thousand or so fossil species known today were known to Darwin. But virtually all the new fossil species discovered since Darwin's time have either been closely related to known forms or, like the Poganophoras, strange unique types of unknown affinity. Denton (ETC) Page 160
And like what we'll consider below when describing some aspects of the Cambrian explosion—phyla seem to hit the road running—life's appearance as in certain cases is characterized by a fossil record without antecedent forms (that is, no evidence leading up to) the gradual progression evolution suggests ...
The molluscs, for example, the earliest representatives of the cephalopods (the group including the octopus and squid), of the bivalves (clams and oysters) or gastropods (snails and slugs), etc. are all highly differentiated when they burst into the fossil record. Denton (ETC) Page 162
The following diagram is from a 1924 edition of an elementary biology text book.
While Darwinists were thinking they'd find intermediates to fill the tree of life's branches (as noted elsewhere; as a required to make the tree a valid concept), they instead run into timeframes that begin with rapid appearances! Not only for the invertebrates at the Cambrian, but also for other groups elsewhere along geologic time:
Some 65 million years ago, a riot of flowering plants burst upon the world. Where did they come from? That question, which Charles Darwin called an "abominable mystery," has perplexed evolutionary biologists ever since. Now a remarkably well-preserved fossil from China promises to unveil the murky ancestry of this most diverse group of plants, in a surprising way. "This may be the most significant fossil flowering plant ever found," says Peter Raven, director of the Missouri Botanical Garden in St. Louis. (from Fossil Plant Hints How First Flowers Bloomed; by Erik Stokstad; Science, May 3, 2002; Vol 296, Page 821)
Plants and even more life forms ...
The story is the same for plants. Again, the first representatives of each major group appear in the fossil record already highly specialized and highly characteristic of the group to which they belong. Perhaps one of the most abrupt arrivals of any plant group in the fossil record is the appearance of the angiosperms in the era known to geologists as the Cretaceous. Like the sudden appearance of the first animal groups in the Cambrian rocks, the sudden appearance of the angiosperms is a persistent anomaly which has resisted all attempts at explanation since Darwin's time. The sudden origin of the angiosperms puzzled him. In a letter to Hooker he wrote: "Nothing is more extraordinary in the history of the Vegetable Kingdom, as it seems to me, then the apparently very sudden or abrupt development of the higher plants." Denton (ETC) Page 163
And again ...
The same pattern is true of the vertebrate fossil record. The first members of each group appear abruptly, unlinked to other groups by transitional or intermediate forms. Already at their first appearance, although often more generalized than later representatives, they are all well differentiated and already characteristic of their respective classes. Take, for example, the way the various fish groups make their appearance. In the space of less than fifty million years, starting about four hundred million years ago, a high proportion of all known fish groups appear in the fossil record. Denton (ETC) Page 164
And still again ...
The story is the same as for the cartilaginous fish—the sharks and rays—which appear first some fifty million years later than most other fish groups. As their first appearance they too are highly specialized and quite distinct and isolated from the earlier fish groups. No fish group known to vertebrate paleontology can be classed as an ancestor of another; all are related to sister groups, never as ancestors and descendants.
The pattern repeats itself in the emergence of the amphibia. Denton (ETC) Page 164
So, what then can account for the jumps in an otherwise gradual evolutionary process? What makes massive alterations happen quickly to adjust some ancestral organism's body plan and it's related functional components of physiology, movement, mating patterns, food consumption patterns, etc.? Remember, a rapid differentiation in an ancestral form is more than some simplistic change in the body ... but behavior, social patterns, instincts, etc. This assumes massive coordinated information changes at many levels. It's not so simple.
But let's say the environment or other stimulus for change could impose massive alterations. The information base, presumably through mutations, is thus changed. How does that get so well coordinated! If every aspect of an organism's life encounters alterations in genetic expression, including the embryonic developmental sequences leading to full grown organisms, well then there is a problem that is often not fully acknowledged by evolutionists ...
As Thomson (1988, 121-22) argues,
There is ... a very widely held notion that evolutionary changes cannot be caused by changes in the deeper, more fundamental events of development. Such changes are often thought inevitably to be lethal. After all, so the argument goes, very many variants that seem to be caused at relatively late stages are lethal; safely changing more fundamental stages must be even more risky. The whole notion of "macromutation" that would significantly alter the early course of development is, in this view, fanciful ... Despite these traditional skeptical views, it seems inescapable that changes in early development are possible and we have to find out how they occur, rather than attempt to dismiss them. Nelson (MC) Page 157
Again, if large changes in latter stages are lethal, then changes to the developmental scheme from the initial embryo on must certainly pose insurmountable barriers to the prospect of survival. New and novel innovations entailing many alterations would surely be confounded by the increased chances for the presence of lethal changes ('bad mutations') along with the beneficial traits. One lethal trait is all that's needed to interrupt the progress of a new branch of evolution's tree.
As Nelson notes, there are other views on solving the problem of sudden appearances. Could some type of asymmetric condition come along just at certain times to loose the constraints that might otherwise apply to evolution?
As Gregory Wray (1992, 131), an opponent of this view, glosses it,
The Cambrian "explosion" of body plans is perhaps the single most striking feature of the metazoan fossil record. The rapidity with which classes appeared during the early Paleozoic, coupled with much of lower rates of appearance for higher taxa since, poses an outstanding problem in macroevolution. One explanation for this pattern is that developmental programs have become too constrained by interaction since the early radiation of metazoans to allow the origin of new body plans. Nelson (MC) Page 158
Diagrams are provided on another page to illustrate the Cambrian explosion leading to the unique body plans referred to here. Yet lifting 'constraints' is an ill defined solution. What might that be in a time frame of several million years ... especially when gradual changes envisioned by Darwin would take hundreds of millions of years to accomplish the same result! Still others continue to consider some free form of evolution followed by a 'lock-in phase.' Is being locked into a set of constraints the condition Darwin presumed? And even in the locked phase, does evolution's process yield any new phyla, even today?
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During the Cambrian explosion, argue Foote and Gould (1992, 1816), "surviving designs stabilized through some form of genetic and developmental locking"—and thus the "unusual speed and flexibility in an Cambrian evolution" was a "followed by constraint upon fundamental anatomical change." This window of opportunity for profound evolutionary change, however, has long been closed. That the window has closed can be seen, Foote and Gould argue, from "the fact that morphological disparity has not increased dramatically since the Cambrian" (1992, 1816) but also (and more important for our analytical purposes) from the extreme difficulty of observing variable major developmental mutants today. The possibilities for fundamental evolutionary change appeared to have narrowed considerably:
It seems very likely that the novelty producible from a chicken is considerably less "novel" than that producible from a poorly integrated, simple metazoan ontogeny of the later Precambrian. ... the general result of the growth of developmental inertia has been to make the biosphere, as a whole, less amenable to change. ... After the initial burst of body plan formation, successful profound ontogenetic changes soon became much less common as internal and external contingencies accumulated (i.e., as ontogenies "hardened" and ecosystems became more "niche-packed." (McKinney and McNamara 1991, 339-40, 363)
While "significant changes in development are required by any model for the Cambrian radiation," Douglas Erwin (1994, 208) notes, "this [temporally asymmetric] model suggests that such changes were a primary forcing mechanism driving the extensive morphological innovation"—perhaps because the organization of the early metazoan genome was in some way distinctive:
There seems to be no alternative but to seek some unusual feature of the primitive genome that would allow it to change in such a way that large coordinated viable morphological changes could take place over short periods of geological time. (Campbell and Marshall 1987, 97) Nelson (MC) Page 164
So what is the potential for any form of life to undergo a rapid change ... if in fact there is an antecedent form to provide the new body type or group of organisms? Building a genome with potential meets another problem. A sudden change in the genome (change in DNA content) implies the addition of information. We are left to ask where this information comes from. And a sudden change in expression requires the information be there in the first place.
Could any infusion of information in a temporary and rapid fashion come by a random process? And bits of misinformation represent the lethality that undoes everything and thus blocks the potential for successful appearances! So the "unusual features" of the primitive genome remain undefined and in some way seem immune to complications that otherwise disrupt macroevolution.
Still, looking at fossils has always revealed appearances of increasingly 'more sophisticated' organism types over time. This is what is meant by fossil transitions. And certainly, if macroevolution is true then these transitions seem to coincide with the expectations for evolution over time.
Series of fossil species like the horse series, the elephant series, the camel series, the mammal-like reptile series, the early birds in and early whales all seem to be strong evidence of evolution.
Another class of fossil evidence comes in individual stratomorphic intermediates.
These are fossils that stand intermediate between the group from which they are descendant and the one to which they are ancestral—both in stratigraphic position and in morphology. They have a structure that stands between the structure of their ancestors and that of their descendants. However, they are also found in the fossil record as younger than the oldest fossils of the ancestral group in an older than the oldest fossils of the descendant group. Wise (CH) Page 226
As recently described by Dr. Jonathan Wells, there is good cause for caution in embracing the commonly accepted examples for evolution. This is the hint given in the last part of the quotation given above. Further descriptions, for example with regard to the horse series, can be read in a book entitled Icons of Evolution written by Dr. Wells. What is reported as evidence to assure us that evolution is supported by the fossil record can come down to nothing more than a misreading of the fossil record. The fossils are no doubt very real, but the result of their misinterpretation is certainly misleading. [We encourage a reading of this book (<bookstore link); as well as a quick look at our separate WindowView feature article on Icons]
Dr. Wise reminds us that the fossil record does contain intermediate species ...
Examples include Pikaia among the cordates, Archaeopteryx among the birds, Baragwanathia among lycopods, Ichthyostega among the amphibians, Purgatorius among the primates, Pakicetus among the whales and Proconsul among the hominids. Wise (CH) Page 227
This evidence would seem to say the process of evolution is at work. But this side of the evolution story isn't without difficulties ...
First, none of the stratomorphic intermediates have intermediate structures. Although the entire organism is intermediate in structure, it's the combination of structures that is intermediate, not the nature of the structures themselves. Each of these organisms appear to be a fully functional organism full of fully functional structures.
Archaeopteryx, for example, is thought to be intermediate between reptiles and birds because it has bird structures (e.g., the feathers) and reptile structures (e.g., teeth, forelimb claws). Yet the teeth, the claws, the feathers and all other known structures of Archaeopteryx appear to be fully functional. The teeth seem a fully functional as teeth, the claws as claws, and the feathers as any flight feathers of modern birds. It is merely the combination of structures that is intermediates, not the structures themselves. Wise (CH) Page 227
These organisms with their combination of fully formed features are sometimes labeled mosaic forms or chimeras. Both terms recognize the presence of features in their complete state and not some intermediate state. These become organisms unique to a group of their own and thus not really intermediates:
As a result, the total list of claimed transitional forms is very small (the above list is very nearly complete) compared to the total number of mosaic forms. The frequency seems intuitively too low for evolutionary theory. The very low frequency of stratomorphic intermediates may be nothing more than the low percentage of mosaic forms that happen to fall in the correct stratigraphic position by chance—perhaps because of random introduction of species by a Creator or the somewhat randomized burial of organisms in a global deluge. Wise (CH) Page 227
Furthermore, while in some cases order is apparent, certain groups reveal little to help in understanding evolution's standard story.
Second, stratomorphic intermediates tend to be found in groups that we have already seen show a fossil-record order consistent with evolutionary order—that is, vertebrates and plants. They are absent among the groups of invertebrates. In some cases a series of intermediates cannot be imagined. More often the imagined intermediates cannot have survived. Transitions from one major group of organisms to another are challenges to the ingenuity of even the most capable macroevolutionists.
Thus, whereas the mosaic feature of claimed "transitional forms" presents a challenge to evolutionary theory, that and the existence of stratomorphic intermediates are consistent with progressive creation and global deluge theories. Wise (CH) Page 228
Dr. Wise hints that other types of events may serve to explain what is observed. While the latter suggestions of progressive creation—where a Creator places life forms on the earth—or other scenario— such as the biblical flood—are not compelling to most scientists and material naturalism, we are free to open our thinking to indeed side step the traditional storyline to consider what else the fossil evidence may be indicating to us. Given the numerous departures we are finding in the window's view, we are well advised to yet again add another distinctive perspective into the larger view.
Writer / Editor: Dr. T. Peterson, Director, WindowView.org
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Quotations from Dr. Michael Denton's "Evolution: A Theory in Crisis" are used by permission granted by 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 and "Mere Creation" (MC) edited by William A. Dembski 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.
Fossils & Cambrian Explosion
Also Consider this: Scientific data appear to be offering us a view of a creative event through information presented in the fossil record! The sudden appearance of life forms on Earth is exactly what is implied by the evidence.
There are ideas and facts that if learned early on in school lead us to really do some searching later on. For the biology or geology student, the concept of an explosion of life forms in a relatively brief 10 million year period is quite astounding. [And more recent estimates for the Cambrian appearances come with even shorter times like 5 or even 3 million years.] These are a mere instance in geologic time. Perhaps this information is taught now, but to our understanding such teachings are not common, certainly not in recent decades. In fact evidence from Canada and China provide immense details for the Cambrian event. The Canadian information was initially withheld for decades starting at the turn of the last century!
Cambrian data, first gathered in the Burgess Shale of Canada could have revolutionized science by publication of fossil finds that first were put in the back room collections of the Smithsonian Institution. This would have been the first insight to a biological explosion. Like the animated cartoon here, this appearance of more sophisticated life forms is rapid and remarkably unique compared to the vastly simpler creatures that inhabited the earth previously.
Today, the fossil record continues to strengthen the presence of a global Cambrian explosion, also dubbed Biology's Big Bang, which takes us back some 530 million years ago. Fossil experts have narrowed this event from tens to 10 million years, possibly less. For evolutionists, the struggle is to account for such rapid change in so brief a time. If Darwin's form of evolution relies on 100s of millions, even a billion plus years, then something is drastically wrong for Darwinism. Those who cannot accept anything but the Darwinist approach have previously and are still now scrambling for explanations. We won't give a long winded account, but the links below will provide graphics and articles to lay out additional details, problems, and concepts associated with the rapid appearance of life on earth. Frankly speaking, life forms appear within their own creation day—albeit an extended 'day,' but a discrete time frame at that.
What use to be simply a matter of scientists saying we don't yet have all the evidence, or the fossil record will fill in the gaps, or whatever, has turned into much more complete information. The fossil record is actually quite extensive and complete. Now it's time to see what the data are telling us!
Link: - Cambrian Era - A Graphic Overview - Comparing ''Evolutionary trees''
The Cambrian explosion is biology's event horizon that appears much like what one would expect for a biblical creation day if captured in he fossil record. Well?
Link: - Window View timeline
Added Perspective:
Sitting here and taking in the window's view is in part an additive process. This brief look at fossils and ancient origins begs further exploration, but with a critical eye. Take each interpretation you see and consider the flip side ... turn over each stone. And even though this feature article alone does not settle everything, there is a measure of counterpoint here that when added to the other problems and unique questions reveals that life's origin is something special and perhaps our existence is not entirely explained by material means. While some ridicule the genesis account in Genesis, the fossil record indicates that appearances of several major groupings of life types come in 'discrete' sudden appearances. Might this be biological evidence in support of the biblical text. At the very least, all this turns one's attention from the standard story to ask questions and to probe a bit deeper into what the evidence may really be hinting at. We've encountered enough interesting twists on the old story that you'll have to agree, it's worth spending a bit more time here to see what the entire view looks like—even if different from what the classical explanations have declared since the mid 19th-century.
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