Time
Required for
Macroevolution to Occur
Questions:
- Was there enough time for chance mutations and natural selection to produce a descent of life forms as proposed by Darwinian evolution theory?
- What are some of the assumptions and issues associated with drawing a 'tree of life' to represent evolution?
- How might we qualify the use of the tree illustration?
Short Answer:
A snapshot description of macroevolution goes something like this ... time is required to achieve an origin to life, once primitive cells arise—however, whenever—time is then required for the gradual developments leading to more and more sophisticated life forms. According to this 'gradualism' of evolutionary theory, this happened one small step at a time over hundreds of millions of years. A 'Tree of Life' is commonly used to illustrate how simple organisms lead to all the known higher life forms of today (see example illustration below). Darwin used the concepts of natural selection and descent with modification to explain how all this occurred given some starting ancestral form of life. This is sometimes called Darwin's general theory on evolution.
Macroevolution is essentially an extrapolation or extension of observations documented over much shorter timeframes (e.g., called microevolution or Darwin's special evolution theory). But this extension of what must have happened for macroevolution is an assumption. And the assumption is fraught with problems that science has yet to explain away—although there is historically the appearance of explanations we now see how critical thinking exposes where these explanations fail (this is the case for examples presented in other feature articles here in the Science Area of WindowView).
The short answer, in plain language, is that life appears to have taken hold on earth so quickly that virtually no time was available for chemical evolution to take place. Beyond this, there is no prospect for an evolution of information nor for chance to account for change in species leading from one major phylum of organisms to the next (as is suggested by a wide variety of tree diagrams). When calculated, the time necessary for chance to do the required work amounts to more time than what has elapsed for the known universe from its creation at t = 0 to the present.
Macroevolution is the assumed backbone of the 'standard story' and it requires time—time that is not there in sufficient duration from the beginning to account for life by evolution's expressed theory.
Macroevolution
Simply put, macroevolution is that part of evolution theory that depicts all life forms coming from one or a few common ancestor(s). The diagram below is one of many different types of renditions that illustrate a 'tree of life;' in this case is limited to plants (and explains why the base of the tree has another large trunk or branch for animals, but is not pictured here).
Macroevolution is an extension of principles that describe what we call microevolution. We look at microevolution in another feature article here.
Click on the image above to view an enlarged version of this illustration.
Consider This:
There are actually two components to Darwin's theory. One we can call the general theory and the other the special theory on evolution. Here, we say general for what is also known as 'macroevolution.' This is to say all life forms appear to have descended from some one or several ancestral forms from long ago. This is the evolution we commonly think of as the 'standard story.' Here chance and randomness along with a natural selection seem to have given us all the life forms—of all the phyla of plants and animals—we see on earth. Also, for this to hold true, one is assuming that numerous smaller variations occur between known and identified forms. This should appear as intermediate forms that are 'moving' or making a transition from species to species and thus leading from one taxonomic group to an entirely different new taxonomic group. Finding the intermediate forms is currently the topic of much attention. However, as noted elsewhere, simply finding a fossil that appears to be an intermediate form may run into numerous other problems in relation to evidence that would conflict with classifying a find as an intermediate.
The special theory is also known as 'microevolution.' This is the part of evolution we can observe as one species yields another due to environmental or geographic pressures. Here one phyla is not seen as giving rise to any other, but then less time is envisioned in seeing the result of processes leading from one species to the formation of new species.
If macroevolution occurred over time, then how much time would be needed to make this general theory workable?
Admittedly, the length of time necessary for evolution by natural selection would have to be very great. As Darwin concedes in the Origin, the greater the length of time, the "better chance of beneficial variations arising and of their being selected accumulated, and fixed." However, the revelation of just how vast an amount of time had elapsed during the history of life on earth was one of the major discoveries of the nineteenth-century geology. Attempting to comprehend this immensity impresses the mind, as Darwin put it, "almost in the same manner as does the vain endeavor to grapple with the idea of eternity." The undeniable capacity of organisms to undergo at least a degree of change, taken in conjunction with the vast time available, seemed to Darwin to greatly enhance the plausibility of his macroevolutionary claims. In an eternity, any degree of change might occur. Denton (ETC) Page 47
Eternity, as mentioned above, collapses when we consider how rapidly life first appeared on earth.
In the 1970s, Elso Barghoorn, a paleontologist, discovered micro-fossils of bacteria and algae in rocks close to 3.5 billion years old. Deposits representative of organic carbon appear in formations 3.8 billion years old. That is also when the first liquid water appeared on earth, and hence the first time life could survive. All life on Earth is water based. No water, no life, but with water, life was possible. It had only to develop, and develop it did, immediately in the presence of water. There were no "billions of years" for the amino acids to combine randomly into life. Schroeder (SG) Page 86
Elsewhere in time, even after simpler life forms populated the earth, dramatic "booms" of new life appear. The Cambrian explosion is often cited as a key example, but this is not the only apparent de novo pulse of new life. Denton notes the sudden appearances of angiosperms (flowering plants) in the Cretaceous, like animals in the Cambrian, and about 400 million years ago the fish all appear within some 50 million years, all these appear as sister groups and not as descendants, and a similar appearance pattern fits the amphibia (Denton (ETC) Pages 162-164). So, multiple observations from the fossil evidence speak of appearances without antecedents—without evolution's ancestral life forms.
So suddenly did life arise on Earth that, the theoretical biologist Francis Crick wrote, "Given the weaknesses of all theories of terrestrial genesis [the origin of life on Earth], directed panspermia [the deliberate planting of life on Earth] should still be considered a serious possibility." Schroeder (SG) Page 86
Panspermia might tell us how life originating elsewhere in the universe might have been transported by chance (or purpose?) to earth. Yet, there is still the problem of time for evolution to occur even at the remote points of origin. Panspermia is simply an idea that 'passes the buck' so to speak!
Sudden appearances (sometimes called punctuations or saltations) seem almost miraculous. Even panspermia as noted here by Crick is "directed" or sudden origin based on an extra terrestrial source. While always seemingly awkward to evolutionists we next turn right into another term: creation. But then again, there are texts in biological publications that use the word spontaneous. What is an origin that is spontaneous if physical properties alone cannot form life? [see elsewhere: chemical origins; thermodynamics]
Without sufficient time to make randomness the driver for evolution, we are faced with a mental leap to explain life's origin. This gets into philosophical problems and leaves only explanations based on assumption.
Added Perspective:
In considering origins there is a multidimensional matrix of issues. A solution in one area still faces linkage to the issues in the rest of the matrix. To just get an idea of the complexity of the matrix of issues, we offer the following section of an older web page that was part of the original WindowView web site:
Beyond the time requirement assumed for macroevolution and various connotations stemming from first impressions of creation science, there is more to seriously consider:
Professor Phillip Johnson, at U.C., Berkeley, reminds us that evolution is our society's popularized creation myth. So popularized and supported by government funding and by the educational system at large, that any concept or mention of creation meets stiff opposition. But if we look at science for what science can tell us, as Prof. Johnson insists, then where is the evidence for evolution? And if the implication is naturalism or materialism explains our being here, then what is the supporting evidence? Are we the product of blind, purposeless, chance as implied by Darwin? Ironically, science may actually be a greater friend to a specific objective view on creation than you might think. If you'll step back from the common party line that evolution explains everything, then you are in for a surprise. (see below "Excerpts and links" on: Johnson on Darwinism and Johnson on Dogma)
Darwin's theory suffers from the lack of modern science. As indicated in the topics described below, other key discussion points weaken the Darwinian view. These topics include: modern biochemistry that provides examples of irreducibly complex features of the cell—something evolution could never produce (see Irreducible Complexity). Beyond this, there is information science used to examine the code within DNA and other evidence for intelligent design (see: Intelligent Design and Information Science); the fossil record revealing a burst of new life forms all within several millions of years at the start of the Cambrian era—something just not in sync with the Darwinian thinking (see Fossils & Cambrian Explosion); a physicist's view on time using relativity to see billions of years fit into six days (see Creation & Time); as well as the numerous conditions that support life ... all of which suggest that our being here is a highly improbable occurrence had the conditions been even slightly different! (see: Conditions Right for Life)
Furthermore, we suggest the picture of a young Earth creationist arguing against the old Earth evolutionist is classic but wrong. These are caricatures and stereo types reinforced by the media. The information we see is not simply biblical content versus the biological findings. Refining the view means looking beyond the headlines. The facts support a new foundation of information that must not be overlooked. And the facts are coming from science as much as anywhere else!
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
Excerpts and links to Feature Articles:
''There is a popular television game show called "Jeopardy," in which the usual order of things is reversed. Instead of being asked a question to which they must supply the answer, the contestants are given the answer and asked to provide the appropriate question. This format suggests an insight that is applicable to law, to science, and indeed to just about everything. The important thing is not necessarily to know all the answers, but rather to know what question is being asked.
''That insight is the starting point for my inquiry into Darwinian evolution and its relationship to creation, because Darwinism is the answer to two very different kinds of questions. MORE on this, read: Prof. Phillip Johnson on Darwinism
''... there is a great deal more to the creation-evolution controversy than meets the eye, or rather than meets the carefully cultivated media stereotype of "creationists" as Bible-quoting know-nothings who refuse to face up to the scientific evidence. The creationists may be wrong about many things, but they have at least one very important point to argue, a point that has been thoroughly obscured ...'' MORE on this, read: Prof. Phillip Johnson on Dogma
''... let's look at the process of evolution. Life is in essence a symbiotic combination of proteins (and other structures, but here I'll discuss only the proteins). The history of life teaches us that not all combinations of proteins are viable. At the Cambrian explosion of animal life, 530 million years ago, some 50 phyla (basic body plans) appeared suddenly in the fossil record. Only 30 to 34 survived. The rest perished. Since then no new phyla have evolved. It is no wonder that Scientific American asked whether the mechanism of evolution has changed in a way that prohibits all other body phyla. It is not that the mechanism of evolution has changed. It is our understanding of how evolution functions that must change, change to fit the data presented by the fossil record. To use the word of Harvard professor Stephen Jay Gould, it appears that the flow of life is "channeled" along these 34 basic directions.'' MORE on this, read: Dr. Gerald Schroeder on Evolution: Rationality vs. Randomness
''Every student of biological evolution learns about peppered moths. During the Industrial Revolution, dark ("melanic") forms of this moth, Biston betularia, became much more common than light ("typical") forms, though the proportion of melanics declined after the passage of pollution-control legislation. When experiments in the 1950s pointed to cryptic coloration and differential bird predation as its cause, "industrial melanism" became the classical story of evolution by natural selection. Subsequent research, however, has revealed major flaws in the classical story. It's time to take another look.'' MORE on this, read: Dr. Jonathan Wells on Evolution's Example Based on the Peppered Moth
Related L ink: Bookmarks - Questions about the ICONs of Evolution
(examples from Dr. Wells!)
Recent finds (reported in 2002 and an example noted elsewhere) persist in linking feathers to dinosaurs. So much anticipation was placed on such a discovery that one find was publicly misrepresented, much to the humiliation of the National Geographic. This is the account given in the following article. More research will explain what feathers are doing on dinosaurs that clearly have no characteristics of flight. The troublesome fact is, feathers, no matter where found are always 'advanced' in their morphology. This leaves far too much unexplained before any conclusions can be drawn (see related discussion touching on this point). But now for a story on how science is too eager to tell a story without solid evidence ...
''When National Geographic published the first pictures of a fossil creature that looked for all the world like a bird-dinosaur, it was hailed as a stunning coup. But now the creature has been exposed as a hoax—the latest in a series of embarrassing reversals in evidence for evolutionary theory.'' MORE on this, read: - Nancy Pearcey on Bird / Dinosaur Missing Link
Writer / Editor: Dr. T. Peterson, Director, WindowView.org
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