Sean McDowell | julho 26, 2016

Is Evolution A Theory in Crisis?

Is Evolution a Theory in Crisis?

SeanMcDowell.org

Michael Denton’s 1985 book Evolution: A Theory In Crisis was one of the most influential scientific critiques of Darwinian evolution in the 20th century. That’s why I eagerly anticipated the release of his 2016 book, Evolution: Still A Theory In Crisis, which both updates and expands his original arguments.

While Denton believes in common descent, and embraces a non-Darwinian law-based explanation for the diversity and complexity of life (although he concedes that his theory “may point to the intelligent design of the universe as uniquely fit for life” ), he launches a trenchant critique of the Darwinian model of adaptive gradualism. Essentially, he defies the claim that macroevolution is merely an extension of microevolution. There exist certain “homologs” or “primal patterns” in nature, claims Denton, which simply cannot be accounted for by cumulative selection. According to Denton, natural selection does play a minor role in the development of various organisms in nature, but there must be other operational forces. He explains:

The Darwinian claim that all homologs were gradually achieved over millions of generations by incremental functionalism—the genetic code, human language, the flower, the diaphragm, etc.—is a phantasm. The near-universal absence of intermediates leading from antecedent structures to the homologs speaks volumes.”

Simply put, there are not the innumerable transitional links Darwin predicted, and in many cases, there is not even conceivable links to account for various “structures” in nature. According to Denton, this is one of the major unsolved challenges for Darwinian evolution.

Denton provides a number of examples in nature that lack Darwinian pathways, such as the cell, limbs, feathers, wings, flowering plants, language, and more. Let’s briefly consider a few of his examples:

SUDDEN APPEARANCE OF THE ANGIOSPERM (group of plants)

The sudden appearance of angiosperms in the fossil record has been a persistent problem for Darwinian evolution. According to Denton, “None of the taxa-defining characteristics of angiosperms, including the key novelties of the flower—sepals, petals, stamens, carpels—are found in any group of plants, extant or fossil, outside of the angiosperm clade.” The angiosperm, along with many other groups of land plants, appears suddenly in the fossil record without antecedents.

According to Denton, the problem is that the evolution of the angiosperm requires large-scale changes that cannot be accounted for by incrementalism: “Not only are there no transitional forms, but to my knowledge, there does not appear to exist anywhere in academic botanical literature even a tentative hypothetical Darwinian functionalist scheme showing how the flower Bauplan or any of its defining homologs—sepals, petals, etc.,—might have emerged via a series of tiny adaptive steps from some ancestral reproductive organ...”

THE TETRAPOD LIMB

It is generally believed that fish are the evolutionary precursors for amphibians. But according to Denton, there is a gap between the tetrapod limb (for amphibians) and the fin (for fish). Some Darwinists have offered Tiktaalik as the best transitional candidate, but the problem is that tetrapod tracks have been found ten million years earlier, which calls the entire scenario into question. Denton concludes:

No matter what Darwinian evolutionary ‘spin’ is put on the gap between fin and hand, there is no avoiding the fact that a significant break does exist in the natural order, and the new evo-devo picture provides no support for any sort of Darwinian gradualist, functionalist scenario…trying to envisage the process as occurring under the direction of gradual natural selection poses herculean challenges.”

FINAL EXAMPLES

Another example Denton raises is the wing of the bat. The problem for Darwinian evolution, says Denton, is that the first known bat appears in the fossil record with fully developed wings (as developed as modern bats), and there is no evidence for transitional precursors. Again, with this example, there is no evidence for the kind of incrementalism Darwinian evolution requires.

The development of language also poses a serious problem for Darwinian evolution. Denton raises an interesting Darwinian paradox: “How could blind unintelligent cumulative selection, the blind watchmaker, have assembled a device—the language organ—of such complexity and sophistication that intelligent humans cannot ‘intelligently’ simulate these unique abilities in a machine?” Denton raises further problems for the origin of language, such as how our intellectual abilities (mathematical, musical, artistic, etc.) could have emerged through a Darwinian pathway when these abilities did not possess any initial utility.

CONCLUSION

Evolution: Still A Theory In Crisis is a challenging book to read. It’s not written for the novice! But if you have the interest and time to wrestle with an important scientific critique of the neo-Darwinian synthesis, it is well worth the investment. Even if you end up disagreeing with Denton (as I do on some points), his book is thoughtful and timely.

Denton concludes that natural selection has a minor role to play in the development of various organisms, but as an explanation for the whole of nature, the Darwinian model of incremental change fails. If he is right, then where do we go from here?

He concludes: “Either the ‘jump’ was…already prefigured into the biology of the ancestral form and its actualization due to internal causal factors according to a structuralist 'laws of form' framework, or it came about as the result of special creation.”

He’s right. The Darwinian model faces significant hurdles, which seem to get increasingly higher. Either the naturalist needs to answer the challenges raised by Denton, pose another naturalistic model (as Denton does at the end of his book), or be open to special creation. There are only so many available options.

Sean McDowell, Ph.D. is a professor of Christian Apologetics at Biola University, a best-selling author of over 18 books, an internationally recognized speaker, and a part-time high school teacher. Follow him on Twitter: @sean_mcdowell and his blog: seanmcdowell.org.

Sean McDowell, Ph.D. is a professor of Christian Apologetics at Biola University, a best-selling author, popular speaker, and part-time high school teacher. Follow him on Twitter: @sean_mcdowell, TikTok, Instagram, and his blog: seanmcdowell.org.