I received the book, Darwin’s Doubt, by Stephen C. Meyer, as a gift and have been reading and reviewing it on this blog. I learn better by processing what I read, and processing, for me, means writing.
In the first installment, I breezed through the first four chapters of the book in which Meyer introduces the problem of “Darwin’s doubt”, the Cambrian Explosion. Darwin knew the sudden proliferation of life forms in the Cambrian era was a problem to his theory, but hoped future discoveries would prove his theory right.
The Theory of Evolution necessarily requires long periods of gradual change in which natural selection works to weed out unproductive traits in favor of productive traits, slowly and almost imperceptibly evolving from simple life forms to more complex life forms and from one life form to another life form.
The Cambrian “explosion” contraindicated Darwin’s Theory of Evolution. Darwin, himself, highlighted that fact, but he assumed that future discoveries would fill in the missing gaps that did not appear in the fossil record in his time. Meyer traces the most relevant history since Darwin’s time to “tell the rest of the story”, which turns out does not confirm his assumption. In fact, subsequent discoveries accentuate the problem.
In the next two chapters, Meyer explains how the scientific community has attempted to fill that gap with solutions that explain away the gap. Rather than question Darwin’s theory, they have moved to the molecular record to vindicate the theory to which the scientific community long ago committed. Meyer carefully explains how the Cambrian gap and less remarkable (but no less significant) Precambrian gap are not bridged by molecular analysis or anatomical analysis.
As a back drop, Meyer highlights the obvious truism that, since there is only one history of life, one history of evolution, the evidence ought to begin to line up to reveal one “tree of life” that Darwin envisioned. Even we if we do not have the full picture, and even with gaps, various evidence from various angles should begin to fill in those gaps, and patterns should begin to emerge.
With no evidence of bridges from Precambrian life forms to Cambrian life forms, scientists began looking for a “deep divergence” somewhere in the more distant past. Presuming that the fossil record is incomplete and proof of the evolutionary progression in the fossil record must be lost, scientists began looking at molecular structures for evidence of the missing progression deep under the fossil structures we see. The assumption was that the progression missing in the fossil record would show up hidden in molecular structures. They supposed that the evidence that does not readily appear in fossil remains must be in hidden in the molecular level.
The deep divergence theory proposes that changes only “seemed” to appear suddenly. The deep divergence hypothesis postulates that the evolutionary progressions must have been at the molecular level, envisioning “a ‘long fuse’ of animal evolution and diversification lasting many millions of years leading up to what only looks like an ‘explosion’ of animal life in the Cambrian, but this history was hidden from the fossil record.” They propose “a long period of undetected or cryptic evolution,” and molecular analysis was thought to be the way to identify the missing progression. (p. 101)
The assumption has been that molecular evidence will fill in the gaps and, together with the fossil record, reveal the “canonical tree of life”. The tree is “canonical” because there can only be one. There is only one history of evolution; there can be only one tree tracing its origin. The term also reflects the orthodoxy that has become Darwinism since the Origin of Species was first published.
If evolution occurred at the anatomical level, it surely occurred at the molecular level. Molecular evolution, therefore, should parallel anatomical evolution, and tracing molecular evolution back should give us clues that may fill in the fossil record gaps, so the theory goes.
Linus Pauling and Emile Zuckerkandl pioneered the molecular clock analysis which became the mechanism for tracing molecular structure back to the original evolutionary divergence of life. Meyer’s book examines the studies by Gregory A. Wray and others. Wray’s study led to a determination that the common ancestor for animal forms of life appeared 1.2 million years ago.
Another major study led by Douglas Erwin, however, reached the conclusion that the common ancestor dates to 800 million years ago, a not insignificant 400 million year swing. Many other studies have been done leading to more divergent and, therefore, more inconclusive results (pegging the common ancestor between 100 million and 1.5 billion years ago). One such study done by Dan Graur and William Martin concluded with 95% accuracy (sarcasm noted) that the divergent date for certain animals falls within a 14.2 billion year window – “more than three times the age of the earth and clearly a meaningless result.” (p. 107)
Meyer observes that scientists who assume the evolutionary theory of life who are doing molecular analysis are forced to ignore these results because they produce obviously impossible conclusions. Molecular studies, no matter what the starting point, should be traceable back to a single point of origin, but they do not. As a result, molecular analysis has led scientists to cherry pick the evidence that conforms to the results they think the studies should reveal based on evolutionary theory “to avoid grossly contradictory results”. (p. 107)
All of this is not to say that scientists might not stumble on the proverbial tree of life, but all of the best efforts to date have failed. They have only produced wildly inconsistent results.
Stephen Meyer concluded the review of the molecular analyses up to the present time by saying, “These studies… assume, rather than demonstrate, the theory of universal common descent.” (p. 109) Some scientists, like Andrew Smith and Kevin Peterson, candidly admit “the idea that there is a universal molecular clock ticking away has long since been discredited.” Whether the “grossly contradictory results” of molecular clock analysis should be seen as discrediting evolutionary theory as a whole, it certainly provides no evidence to trump the fossil record.
The fact is, however, that most scientists are committed to the Darwinian model in spite of failed attempts to explain the fossil record gap. Common descent of all animal forms is assumed as fact (though it has not been demonstrated in fact); and the effort of modern scientists is, therefore, focused on finding evidence to fit that model, even if it must be “helped” along.
In this vein, computer software used to analyze data is written to produce trees showing common ancestors and branching relationships “regardless of the extent to which the genes analyzed may or may not differ.” (p. 110) So sure of the evolutionary theory are most modern scientists, that they set up their analytic models to produce the results they are assured certain should occur, based on their pressupositions.
Some, like Simon Conway Morris, a leading evolutionary biologist, however, candidly suspect that deep divergence hypothesis is not a genuine answer to the Cambrian problem.
Meanwhile, Darwin’s tree of life continues to be the only paradigm accepted by modern science. The BBC called it the “Darwinian Sistine Chapel” in a 2009 documentary commemorating the life and legacy of Charles Darwin. Richard Dawkins boldly proclaimed that a competitive look at genetic sequences and “anatomical resemblances throughout all living kingdoms” reveals the family tree “thoroughly and convincingly laid out”. (p. 115) Jerry Coyne also claims that “gene sequences independently confirm the same set of evolutionary relationships – the same basic tree – established from the analysis of anatomy.” (Id.)
In reading Meyer’s book, one wonders what tree (or actually which tree) they are looking at.
As a layman, it is difficult to understand the dogmatic orthodoxy of the modern scientific community in light of clearly contravening evidence. Meyer goes to some length to switch back and forth between molecular and anatomical analyses to show how contradictory and inconclusive the studies are. The results are so conflicting that a few people are breaking from the ranks to concede that the tree concept has not proven out: the evidence suggests that “the evolution of animals and plants isn’t exactly tree-like.” (Quoting a 2009 article in the New Scientist, p. 119) Michael Syvanen even concluded from his own studies that his analysis “annihilated the tree of life. It’s not a tree anymore, it’s a different topology altogether.”
The molecular clock analysis fails to show a single divergence point, a necessary corollary to the concept of a tree with branches shooting off from the trunk (a concept that is central to Darwinism). Linus Pauling and Emile Zuckerkandl, the fathers of the molecular clock concept, believed (rightly so) that studies of comparative anatomy and DNA sequences should generate similar phylogenetic trees. If they could match up the anatomical and DNA pictures, they believed “the” tree would begin to become evident.
Since that time, however, the studies have repeatedly shown that phylogenetic “trees” drawn from anatomy and the “trees” drawn from molecules do not match and often contradict each other. Meyer points out the obvious when he says that different “stories” (the anatomical and molecular stories) may be false, but they cannot both be true. The bold statements by Dawkins, Coyne and Atkins that the anatomical and molecular data show an unambiguously similar, single tree, therefore, are “manifestly false”. (p.124)
Trees created by using various anatomical data points lead to wildly divergent results compared to trees created using various molecular data points. The one “canonical tree of life”, if indeed there is one, should begin to come into focus as any of the data points, anatomical or molecular, are traced back, but that is not what we see. It should not matter the starting point; the pathways back to the origin should converge – but they don’t.
Trying to draw a single tree using only anatomical data is equally frustrating. Trees constructed using different developmental and anatomical characteristics often conflict, as do attempts to trace back molecules to an origination point. Meyer walks through some examples of conflicting studies using anatomical and developmental characteristics to show how trees created using different characteristics yield conflicting results – and not just conflicting results, but mutually exclusive relationships among the various characteristics.
Meyer ends this portion of the analysis by showing that trees derived from different anatomical starting points produce conflicting results as to trees derived from different molecular starting points, and trees derived from anatomical starting points, as it should be expected at this point, differ from trees derived from molecular starting points. The statements of Dawkins and Coyne that suppose one tree clearly standing when all the analysis is applied simply does not exist. The statement of Peter Atkins, that “there is not a single instance of the molecular traces of change being inconsistent with our observations of whole organisms” (p. 115) is utterly untrue.
The theme of chapters 5 and 6 is that there is only one history of life and so there can be only one tree of life, if the elusive “canonical tree” even exists. That one history should yield evidence of one common ancestor occurring at one point in time from which all subsequent life forms grew and evolved. This must necessarily be true if Darwinism is true. Whether we study anatomical traits or molecular traits, the evidence should reflect one story, but it does not.
“[T]he animal phyla consistently defy attempts to arrange them into the pattern of a single tree.” (p. 132)
Meyer concludes the 6th chapter stating that “these contradictory results call into question the existence of a canonical tree of animal life.” (p.134) He says, “the evidence should converge on a common family tree – if indeed we are looking at evidence of true history. ” (p. 135) So far, through the first six (6) chapters of Darwin’s Doubt, the originating divergence point and Darwin’s tree of life, itself, remain “lost” to science. In the next blog article we will explore other solutions that have been tried, and failed.