Should We Stop Criticizing the Doctrine of Universal Common Ancestry?


Jonathan Wells

I sometimes argue that the evidence for common ancestry is not what Darwinists claim. Some friends have suggested that Discovery Institute Fellows should abandon this line of argument, because common ancestry is compatible with some forms of intelligent design theory and because criticisms of common ancestry are likely to alienate other scientists. What follows is my personal response to this suggestion.

According to the mission statement of the Center for the Renewal of Science and Culture (CRSC): "Materialistic thinking dominated Western culture during the 20th century in large part because of the authority of science. The Center for the Renewal of Science and Culture seeks, therefore, to challenge materialism on specifically scientific grounds. Yet Center Fellows do more than critique theories that have materialistic implications. They have also pioneered alternative scientific theories and research methods that recognize the reality of design and the need for intelligent agency to explain it." (From the CRSC brochure)

I am a Fellow of CRSC primarily because I am committed to challenging materialism by distinguishing it from empirical science and especially to exposing the former when it masquerades as the latter. I also consider intelligent design theory (IDT) to be the best alternative to Darwinian evolution; but regardless of how IDT fares now or in the future, I remain committed to challenging materialism on scientific grounds.

Empirical science requires theories, somehow and at some point, to be compared with evidence. Prudence will dictate that theories long established should not be changed for light and transient causes. But when a long train of exaggerations and distortions evinces a desire to promote an idea regardless of the evidence, then it is our right, it is our duty, to criticize that idea as a philosophical doctrine rather than a scientific theory.

For example, Darwinists have argued that all living organisms are descended from a common ancestor, and that the universality of the genetic code is important evidence for this. In 1966 Bruce Wallace wrote: "That all living organisms use precisely the same code is elegant evidence that these organisms have arisen from but one source, that life on earth has had but a single source from which all present forms have evolved." (Chromosomes, Giant Molecules, and Evolution, p. 156) In 1973, Theodosius Dobzhansky wrote that the genetic code is "universal," suggesting "that life arose from inanimate matter only once and that all organisms, no matter how diverse in other respects, conserve the basic features of primordial life." (The American Biology Teacher 35, p. 127)

This line of argument is not merely a thing of the past. In 1998, the U.S. National Academy of Sciences published a booklet (written with the help of Bruce Alberts, Eugenie Scott, Tim Goldsmith, and Maxine Singer, among others) stating that "all organisms use the same molecular codes to translate DNA base sequences into protein amino acid sequences. This uniformity in the genetic code is powerful evidence for the interrelatedness of living things, suggesting that all organisms presently alive share a common ancestor that can be traced back to the origins of life on earth." ("Teaching About Evolution and the Nature of Science," Ch. 2, p. 4) And the September, 2001, PBS Evolution series informed viewers: "The fact that the blueprints for all living things are in the same language the genetic code of DNA is powerful evidence that they all evolved on a single tree of life."

Yet biologists have known for years that some bacteria, algae and single-celled animals do NOT have the same genetic code as most other organisms. Darwinists claim that the exceptions are unimportant, since they "know" that the aberrant organisms are descended from organisms that had the standard code. But the code itself was supposed to be the primary evidence for such descent, and no comparable evidence is offered to replace it. Clearly, the Darwinists' "knowledge" in this case is philosophical rather than empirical.

The non-universality of the genetic code is not a minor quibble, but part of a general pattern. In 1991, Phillip Johnson argued in Darwin On Trial that common ancestry the so-called "fact of evolution" is not an empirical hypothesis for Darwinists, but a logical consequence of their naturalistic philosophy. As such, it is immune to empirical disconfirmation. Even when evidence cited as primary support for the idea turns out to be false, the idea survives. We see this in molecular phylogeny (in which the contortions needed to protect the common ancestry of the major kingdoms make Ptolemaic epicycles look downright elegant), the fossil record (in which the absence of a common ancestor for the major animal phyla is still dismissed as an artifact of incomplete collection, even though 150 years of collecting have shown that the Cambrian explosion is real), and vertebrate embryology (in which dissimilarities in early embryos that do not support the doctrine of common ancestry are explained away, on the grounds that early development evolves more easily than we thought).

The truth is that MOST of the evidence cited in support of common ancestry at the levels of kingdoms, phyla and classes has had to be explained away to protect the idea of common ancestry. But if most of the evidence must be explained away, then its clear that were dealing with a philosophical doctrine rather than empirical science.

Of course, common ancestry may be true at lower levels of the biological hierarchy. For example, everyone would probably agree that all human beings are descended from common ancestors. And even many biblical creationists regard the ability of members of the cat family to hybridize as evidence that they share a common ancestor. In the absence of evidence, however, why should we accept as "fact" the idea that ALL organisms are descended from a common ancestor?

One might argue that it is strategically smart to set aside the common ancestry question in order to pursue the more important question of design. Twelve years ago I would have argued this myself, because I thought the Darwinian exclusion of design was an unwarranted philosophical extrapolation from otherwise sound science. After studying the evidence for the past twelve years, however, I am now convinced that Darwinian evolution is not and never has been sound science. Its systematic distortions of the evidence reveal it to be philosophical through and through. Except for minor changes within existing species, most Darwinian empirical claims are deeply misleading. It's lies all the way down.

I realize that many scientists don't like to hear the evidence for common ancestry questioned. To the extent that they feel this way, however, they are merely deferring to peer pressure, or they have replaced empirical science with naturalistic philosophy. Until they muster the courage to resist pressure from their more dogmatic colleagues and face their own philosophical presuppositions, I don't see them accepting intelligent design theory anyway.

I agree that the doctrine of universal common ancestry is logically compatible with some forms of intelligent design theory. It seems to me, however, that the doctrine of universal common ancestry is primarily a deduction from naturalistic philosophy rather than an inference from biological evidence. For that reason, I am no longer willing to grant it immunity from criticism on strategic grounds.

Jonathan Wells, Ph.D.
Senior Fellow
Discovery Institute
Seattle, WA