Today’s New Reason To Believe

Posted by Fazale ‘Fuz’ Rana, Ph.D.

Newly Discovered Example of Convergence Challenges Biological Evolution

I love TiVo. It’s a lot of fun to pause live TV (particularly when the big game is on), rewind it, and play it back again.

Biological evolution has nothing in common with TiVo, however. As the late evolutionary biologist Stephen Jay Gould highlighted in his book Wonderful Life, if one were to push the rewind button, erase life’s history, and then let the tape run again the results would be completely different each time.

The very essence of the evolutionary process renders evolutionary outcomes nonrepeatable. According to the concept of historical contingency, chance governs biological and biochemical evolution at its most fundamental level. Evolutionary pathways consist of an historical sequence of chance genetic changes operated on by natural selection, which, too, consists of chance components. As a consequence, if evolutionary events could be repeated, the outcome would be dramatically different every time. The inability of evolutionary processes to retrace the same path makes it highly unlikely that the same biological and biochemical designs should appear repeatedly throughout nature among unrelated organisms.

Contrary to what’s expected, evolutionary biologists note that biological convergence is widespread. As I noted last week, convergence refers to the extensive pattern in nature where unrelated organisms possess nearly identical anatomical, physiological, behavioral, and biochemical characteristics. According to the evolutionary paradigm, undirected natural processes yielded the identical outcome because the forces of selection channeled evolutionary pathways to the same endpoint.

Researchers Brian Beatty and Bruce Rothschild have uncovered another remarkable example of biological convergence. From an evolutionary standpoint, it appears as if toothed and baleen whales developed the ability to dive deep into the ocean independently from each other. (Go here for a popular article on this discovery and here for a technical paper.)

For whales to dive, they must have physiological adaptations that allow them to avoid decompression syndrome. Rapid pressure changes—such as what occur during deep diving—can force air bubbles out of the blood vessels. When this happens, it can cause the blood vessels to rupture, denying cells of blood, oxygen, and nutrients. This loss causes the cells to die, leaving lesions behind.

The scientists used this principle to assess susceptibility of ancient whales to decompression syndrome. They analyzed vertebrae of 331 individual modern and 996 fossil whales. The conclusion was that the two lineages of whales must have evolved the ability to avoid decompression syndrome independently. This scenario contravenes the expectation of most evolutionary biologists, who postulated that the shared ancestor of toothed and baleen whales must have had the ability to dive deep without suffering from decompression problems.

According to Erich Fitzgerald, an Australian paleontologist, “They have come up with a quite surprising story.” The surprise expressed by Fitzgerald stems from the notion that evolutionary outcomes should not repeat. Yet, in this instance and others it appears as though evolution has generated the same outcomes over and over again.

Biological convergence not only raises questions about the validity of biological evolution, it also points to the work of a Creator. As I argue in my new book The Cell’s Design designers and engineers frequently reapply successful strategies when they face closely related problems. Why reinvent the wheel? It’s much more prudent and efficient for an inventor to reuse the same good designs as much as possible, particularly when confronted with a problem he or she has already solved.

The tendency of engineers and designers to reuse the same designs provides insight into the way that a Creator might work. If human engineers, made in God’s image, reutilize the same techniques and technologies when they invent, it’s reasonable to expect that a Creator would do the same. If life stems from the work of a Creator then it’s reasonable to expect that the same designs would repeatedly appear throughout nature. Use of good, effective designs over and over again would reflect His prudence and efficiency as a Divine Engineer.

It looks as if life is God’s TiVo.

Posted by Fazale ‘Fuz’ Rana, Ph.D.

Newly Discovered Example of Convergence Challenges Biological Evolution

“It’s like déjá vu all over again.” This expression, attributed to Hall of Fame catcher Yogi Berra, has become synonymous for something that happens over and over again—and probably shouldn’t.

Evolutionary biologists are confronted with their own form of déjá vu, known as convergence. This term refers to the widespread pattern in nature in which unrelated organisms possess nearly identical anatomical, physiological, behavioral, and biochemical characteristics. The wings of birds and bats represent one textbook example. Birds and bats belong to different groups, with birds assigned to the class Aves and bats to the class Mammalia. According to the evolutionary paradigm, undirected natural processes yielded the identical outcome (wings, in this case) because the forces of selection channeled evolutionary pathways to the same endpoint.

This explanation doesn’t square up, however. If biological systems are the product of evolution, then the same biological systems should not recur throughout nature. Chance governs biological and biochemical evolution at its most fundamental level. Evolutionary pathways consist of a historical sequence of chance genetic changes operated on by natural selection, which, too, consists of chance components. The consequences are profound. If evolutionary events could be repeated, the outcome would be dramatically different every time. The inability of evolutionary processes to retrace the same path makes it highly unlikely that the same biological and biochemical designs should repeatedly appear throughout nature.

The concept of historical contingency embodies this idea and is the theme of Stephen Jay Gould’s book Wonderful Life. To help clarify the concept of historical contingency, Gould uses the metaphor of “replaying life’s tape.” If one were to push the rewind button, erase life’s history, and then let the tape run again, the results would be completely different each time. The very essence of the evolutionary process renders evolutionary outcomes nonrepeatable.

And yet, over the last decade or so, evolutionary biologists have discovered a number of examples of convergence at the organismal and biochemical levels. (For more information, see these articles on convergence and repeated evolution.)

In my most recent book, The Cell’s Design, I document over one hundred examples of convergence at the biochemical level and argue that the widespread occurrence of the multiple repeated origins of a wide range of biochemical systems raises significant questions about the validity of evolutionary explanations for life’s origin and diversity.

Scientists from Purdue University have really uncovered another remarkable example of biochemical convergence in plants. (See here for journal article and here for popular article.) These researchers demonstrated that a specific enzyme (known as a cytochrome P450-dependent monooxygenase) appears—from an evolutionary vantage point— to have independently emerged in two separate instances in lycophytes and angiosperms. This enzyme plays a key role in the synthesis of lignins.

Lycophytes, such as clubmosses, are an ancient lineage of vascular plants that appeared about 420 million years ago. From an evolutionary standpoint, they represent a separate branch from the lineage that produced flowering plants.

All vascular plants make use of a class of large, complex molecules called phenolic lignins in the xylem. The phenolic lignins are polymers. These types of compounds are large molecules comprised of repeating subunit molecules (called monomers.) The different types of vascular plants produce lignins consisting of characteristic subunits. For example, gymnosperms produce lignin made up of guaiacyl monomers. Angiosperms manufacture lignins composed of a mixture of guaiacyl and syringyl monomers. Plant scientists generally regard lignins derived from syringyl monomers as exclusive to angiosperms. This view implies that the enzymes used to make this monomer must have evolved relatively late in evolutionary history when angiosperms appeared on the scene.

Interestingly, there are lycophytes that possess lignins composed of the syringyl monomer. The Purdue researchers determined that the enzyme (ferulic acid/coniferaldehyde/coniferyl alcohol 5-hydroxylase, a cytochrome P450-dependent monooxygenase) that directs metabolites down the pathway that yield syringyl monomers must have evolved independently in lycophytes and angiosperms to yield enzymes that perform identical functions.

Like Yogiisms, this conclusion makes little sense within the evolutionary paradigm, particularly in light of all the other examples of biochemical convergence. It looks as if evolution has repeated itself over and over again—and it shouldn’t have.

Paleontologist J. William Schopf, one of the world’s leading authorities on early life on Earth, has made this very point in the book Life’s Origin.

Because biochemical systems comprise many intricately interlinked pieces, any particular full-blown system can only arise once…Since any complete biochemical system is far too elaborate to have evolved more than once in the history of life, it is safe to assume that microbes of the primal LCA cell line had the same traits that characterize all its present-day descendents.

This pattern, expected by Schopf and other evolutionary biologists, is simply not observed at the biochemical level. An inordinate number of examples of molecular convergence have already been discovered. And undoubtedly more will be uncovered in the future.

Next week I’ll visit the topic of convergence all over again by describing another newly discovered example and discuss how “repeated evolutionary outcomes” provide evidence for the work of a Creator.

Posted on February 14th, 2007 by Virgil L. Robertson, DC, QME, FAFICC

Bio: Dr. Robertson received his Chiropractic doctorate from Southern California University of Health Sciences in 1985, and currently serves as Clinical Director at Brea Canyon Pain Relief and Rehabilitation Center in Brea, California.

The arch in the small of your lower back is known as the “lumbar lordosis” and it plays an important role in allowing humans to stand upright and walk on two feet. If you’ve ever seen a pregnant woman negotiating her way down the aisle of a supermarket, you’ve surely noticed that the bigger the belly, the more the mother-to-be has to arch backward to keep her balance. Recently, researchers from Harvard University and the University of Texas examined this biomechanical phenomenon and made some fascinating discoveries, which were reported in the December 2007 edition of Nature.

As it turns out, the spines of men and women are not created equal. In fact, it now appears that women have been designed with specific anatomical features that enable them to safely carry the large asymmetric loads associated with pregnancy. Specifically, the research team headed by anthropologist Dr. Katherine Whitcome found that the lumbar spine of human females differs significantly from that of males. The female spine possesses an additional wedge-shaped vertebra, which substantially increases lordotic curvature in women (three wedge-shaped lumbar vertebrae in women vs. two wedge-shaped lumbar vertebrae in men). This feature allows expectant mothers to comfortably assume more extended (lordotic) postures during pregnancy. Additionally, the researchers found that the lumbar zygoapophyseal joint surfaces of women are proportionally larger and more coronally oriented than corresponding posterior joint structures in men. This distinctively female spinal configuration provides a more stable base for posterior weight bearing (hyperlordosis) and helps prevent anterolisthesis (fracture and forward slipping) of the lumbar vertebrae in pregnant women. As pregnancy proceeds and the fetus grows larger, mom simply leans back a little further (up to 28°) to balance the center of gravity over her hips—it’s a simple yet ingenious biomechanical system!

These new research findings indicate that women are particularly well equipped to safely bear the heavy anterior loads that come with pregnancy. Without these anatomical design features, pregnant women would have great difficulty balancing their unborn bundles of joy, and would be much more susceptible to myoligamentous (muscular) injuries and vertebral fractures during the third trimester of gestation.

The research team also reports that the spines of extinct hominid species (australopithecines) possessed the same kind of anatomical features and dimorphic disparities found in humans. The identification of anatomic features and biomechanical systems uniquely common to bipedal primates is not surprising. Previous authors have identified numerous anatomical and physiological characteristics in bipeds that differ from those found in quadrupeds. While the authors of this new study interpret their findings in terms of an evolutionary framework, it should be noted that these findings are, likewise, fully consistent with the predictions of RTB’s Testable Creation Model. In fact, explaining why the unique features of bipedalism appear suddenly in the hominid fossil record some seven million years ago (in the absence of transitional intermediate forms), has proven to be a substantial challenge for evolutionary biologists.

When considering the abundance of elegantly engineered biomechanical systems found in the human body, it’s hard not to be impressed by the obvious hallmarks of design. To quote British physicist Paul Davies, “The impression of design is overwhelming.”

These latest research findings fall into a long line of evidences that provide support for the existence of an Intelligent Designer. The generation of such exquisitely engineered biosystems is simply beyond the scope and capability of random mutation and natural selection.

For more on the emergence of bipedalism see Who Was Adam?