Do Humans Have Genes for Laying Eggs?

Part 12

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This series has been responding to the theistic evolutionary book Adam and the Genome.1 We have been focusing specifically on the first several chapters (written by Dennis Venema), which claim to detail the evidence for evolution in general, and for the nonexistence of Adam and Eve in particular. In our last three posts on chapter two, we began to explore the analogy that Venema makes between language change and evolutionary change.

Venema thinks this analogy uncovers genetic patterns that are difficult to explain apart from evolution. We have dealt with Venema’s claims about patterns in genetic sequences that he thinks are functionally redundant. In this post, we explore his claims about genetic sequences that he thinks have lost their function.

The Curious Case of Pseudogenes

For the remainder of chapter two, Venema sets his sights on these purported nonfunctional sequences. Specifically, Venema spends several pages discussing pseudogenes. As their name implies, Venema thinks these are broken remnants of once-functional genes. Via analogy to human language, genes are like words, and pseudogenes are like misspelled words.

At first pass, it might seem unreasonable to ask if pseudogenes have a function. Why wouldn’t misspelled words be recognized as nonfunctional? On closer inspection, the reason becomes clear: DNA is like a language, but it is currently a foreign language.

DNA is like a language, but it is currently a foreign language.

Consider the ramifications of this fact. By analogy, let’s say that a native English speaker decides to learn Russian. Let’s also say that this student acquires a proficiency of 5% in the Russian language. How foolish it would be for this student to travel to Russia and apply for a position of proofreader. Being ignorant of 95% of the language would make it nearly impossible for this student to know which words are correctly spelled, and which ones are not.

How much of the language of DNA do we speak? Unlike human languages, scientists do not become proficient in the language of DNA by studying textbooks and databases of vocabularies. Instead, they learn the language by doing experiments. At this stage, it’s worth repeating what we published in our book chapter on human genetics:

The members of BioLogos have made a host of claims on their website about shared “pseudogenes” and other types of purported shared biological “mistakes” in apes and humans. . . . In reality, hardly any actual experiments have been performed on the billions of DNA letters in humans and chimpanzees. “Pseudogene” actually represents a premature label for a particular segment of DNA that resembles a broken gene but which had never been experimentally tested for function. Thus, virtually all claims that BioLogos and other evolutionists have made about genetic “mistakes” are not arguments for evolution but bald assertions without a basis in experimental fact.

Clearly, the scientific community is just beginning to study the language of DNA. Thus, our proficiency is currently very low.

The history of genetics reveals why this is the case. For decades, genes have been the basic unit of study, and scientists have become fairly proficient in recognizing how genes function. However, genes constitute only around 5% of the human genome (the complete sequence of human DNA). The other 95%, which represents non-gene DNA, is largely a mystery to the scientific community—very little of it has been experimentally manipulated. Thus, our proficiency in the language of DNA is likely less than 5%.

Yet Venema acts as if he’s fluent in the language of our DNA.

Like so many evolutionists, Venema doesn’t see evolution as one of many hypotheses to be tested.

Why? If hardly any experiments have been performed on the function of around 95% of our genome, why would Venema make such bold claims? The answer derives from Venema’s position on evolution. Like so many evolutionists, Venema doesn’t see evolution as one of many hypotheses to be tested. In his mind, evolution is the test of various hypotheses, and Venema “tests” genetic sequences for function via the filter of evolution. The existence of “broken genes” fits the hypothesis of evolution, and Venema simply concludes that nonfunctional genes (pseudogenes) exist.

The Even More Curious Case of the “Egg-Laying” Pseudogene

The specific pseudogene with which Venema closes his chapter raises even more problems for his position. By analogy, let’s again treat genes as DNA words. Pseudogenes would be misspelled words—or apparently misspelled words. Naturally, the label “misspelled” is applied after comparison to the “correctly” spelled gene word. Venema’s closing pseudogene example stretches this analogy to its breaking point.

In short, Venema claims that humans have the broken, misspelled remnants of an egg-laying gene. Normally, this vitellogenin gene participates in yolk formation in creatures like chickens that actually lay eggs. In humans, where babies are nourished in the womb, it’s no surprise that egg-laying genes do not exist. However, Venema claims that the dilapidated remains of this once-functional gene exist.

The problems with his claim are manifold. The egg-laying “pseudogene” in humans is only 39% identical to the functional vitellogenin gene in chickens.2 Furthermore, since the DNA alphabet has only 4 letters, a random match does not result in 0% identity; rather, a match between two completely random sequences produces 25% identity (an average match of 1 in 4). In other words, a 39% identity is more like a 20% identity on a 100-point scale.

By analogy to words, this level of identity is almost meaningless. For example, we could find two words that match in only 20% of their letters. As an illustration, the word zebra is a 5-letter word; since only 1 of its 5 letters matches the word quota,3 these two words are 20% identical.

Is zebra a broken, nonfunctional relic of the word quota? By Venema’s logic, it is.

Obviously, this claim for an evolutionary relationship between zebra and quota is nonsensical. How much more so in the vitellogenin example that Venema cites.

If this were the only problem with Venema’s analogy, his vitellogenin example would be very poor. What makes his example even worse is the multi-year history that precedes its inclusion in the book.

Since 2010, Venema has been flaunting the vitellogenin pseudogene example in the face of creationists, publicly laying down the gauntlet.

Since 2010, Venema has been flaunting the vitellogenin pseudogene example in the face of creationists, publicly laying down the gauntlet. However, Venema’s published challenges have grossly exaggerated and misrepresented the actual level of identity between the human and chicken sequences. In 2015, a creationist discovered and published the actual (meaningless) level of DNA identity between the human egg-laying “pseudogene” and the functional chicken gene. Venema then publicly misrepresented the new discoveries, contradicted his earlier statements, and misrepresented the level of identity in yet another way. Finally, in Adam and the Genome, Venema brought his depictions of the actual level of identity to a more realistic level. Yet he never retracted his earlier claims, never corrected his factually erroneous accusations against the creationist researcher, never acknowledged the pioneering work of the creationist who first made the discovery, and continued to insist that an egg-laying “pseudogene” exists in human DNA. In fact, Venema has continued to cite his earlier vitellogenin claims even after the publication of Adam and the Genome.4

This type of behavior is very inconsistent with the stated commitment of BioLogos to “humility and gracious dialogue with those who hold other views”5 [emphasis in original]. It flies in the face of Venema’s assertion that BioLogos is “a place where people of differing views are welcomed, and gracious dialogue is possible.”6

Because Venema’s egg-laying “pseudogene” example continues to occupy such a prominent place in his own writings, and because BioLogos regularly boasts about their commitment to “humility and gracious dialogue with those who hold other views,” we will be exploring the history of this controversy in depth over the next two posts.

Footnotes

  1. Dennis R. Venema, and Scot McKnight, Adam and the Genome: Reading Scripture after Genetic Science, Grand Rapids, MI: Brazos Press, 2017.
  2. Jeffrey P. Tomkins, “Challenging the BioLogos Claim that a Vitellogenin (Egg-Laying) Pseudogene Exists in the Human Genome,” Answers Research Journal 8 (2015): 403–411.
  3. Technically, since the English language has only 26 letters, random matches occur about 4% of the time. Thus, a 1-in-5 match represents a 20% identity on a 96-point scale. If we were to convert this to a 100-point scale, the identity would be even lower.
  4. Dennis Venema, “Adam and the Genome: Some Thoughts from Dennis Venema,” BioLogos (blog), February 15, 2017, http://biologos.org/blogs/jim-stump-faith-and-science-seeking-understanding/adam-and-the-genome-some-thoughts-from-dennis-venema.
  5. About Us, BioLogos, http://biologos.org/about-us/our-mission/.
  6. Venema, “Adam and the Genome: Some Thoughts from Dennis Venema.”

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