Today’s New Reason To Believe

David H. Rogstad, Ph.D.

Some members of the creationist community have questioned astronomers’ explanation for the replenishment of short-period comets in our solar system. Instead, these skeptics argue that the present density of such comets is an indicator of a young solar system and Earth. All agree that comets have a finite lifetime. After a limited number of orbits, they are either dissipated by their interactions with the Sun, with some eventually breaking apart, or they are gravitationally ejected from the solar system, or they strike one of the planets and are destroyed. So, unless there is some mechanism for their replenishment, astronomers should not expect to see short-period comets if the solar system is old. Since scientists do see these comets, there must be a mechanism, or the solar system must be young.

Astronomers have proposed that comets come from two belts of debris in the outer extremities of the solar system left over from its formation. The nearer of the two is called the Kuiper belt. It lies just beyond the orbit of Neptune and is believed to be the source of most short-period comets. The more distant belt is called the Oort cloud and is believed to be the source for most long-period comets. Objects are dislodged from these belts into an orbit that passes closer to the Sun either by internal collisions or by gravitational interactions from planets (in the case of the Kuiper belt) or from nearby stars (in the case of the Oort cloud).

More than one thousand objects have been discovered and catalogued in the region of the Kuiper belt (Kuiper belt objects, or KBOs), providing direct evidence for its existence. The planetoid Pluto is one of the largest of these objects. Astronomers speculate that there are at least 70,000 KBOs greater than 100 km in diameter. Evidence for these has recently come from occultation observations reported previously here (9/28/06).

While there has been no direct evidence for the Oort cloud, that scenario is beginning to change as a result of two different lines of research. First, a growing number of observations, especially in the infrared part of the light spectrum, show evidence for extended clouds of material, not unlike the Oort cloud, in the outer regions surrounding certain stars under investigation for new planets and solar systems. An example is discussed here.

The second line of research appears in a study performed by astronomers, J. T. Wickramasinghe and W. M. Napier, published in a recent issue of Monthly Notices of the Royal Astronomical Society. They modeled the vertical movement of the Sun through the plane of the Galaxy that occurs with a period of about 25-35 million years. The astronomers then calculated the expected flux of comets that would come from an Oort cloud, if present, due to galactic tides and encounters with molecular clouds as a consequence of this movement. They established agreement with the ages of well-dated terrestrial impact craters in the past 250 million years.

Further research stands to confirm or negate both lines of evidence. RTB expects that such testing will lay to rest the issue of cometary replenishment, thereby affirming the ancient age of the solar system and Earth.

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.

by Dr. Jeffrey Zweerink

Part of my attraction to gamma-ray astronomy relates to the types of objects it observes. My graduate research focused on an object called Markarian 421. It is an active galactic nucleus (AGN) located about 360 million light-years away in the constellation Ursa Major. A massive black hole—in excess of a million times the mass of the sun—provides the engine generating the gamma rays in this object. As shown in the image below, a disk of material (known as an accretion disk) surrounds and feeds the black hole, giving rise to long jets emanating along the axis of the disk.

Astronomers used optical observations of another similar object, named OJ 287, to provide an important test of Einstein’s theory of general relativity (GR). At 18 billion solar masses, the black hole in the center of OJ 287 ranks as the most massive black hole known in the universe! Since 1983, a series of optical outbursts has allowed astronomers to determine that another, smaller black hole orbits OJ 287 and crosses the accretion disk surrounding OJ 287. An optical outburst or flash occurs each time the smaller black hole crosses the accretion disk.

With enough outbursts detected, astronomers calculated when the next outburst would occur. According to GR, the strong gravitational fields from the two black holes affect the timing of the pulses in two ways. First, the location of the closest approach of the smaller black hole moves around the larger black hole with each orbit; Mercury demonstrates this effect also. The fact that general relativity properly described this otherwise anomalous behavior served as one of the first confirmations for GR’s validity. Second, two close-orbiting massive objects emit gravitational radiation, which causes the orbit to shrink.

Scientists expected an outburst from OJ 287 in September 2007. Predictions accounting for the emission of gravity waves placed the outburst twenty days earlier than predictions without gravity wave emission. According to an article in Nature, the observed outburst occurred within one day of the prediction that included gravity waves.

These results buttress Einstein’s theory of general relativity by confirming the existence of black holes—which do not occur in Newtonian gravitational theories—and by accurately accounting for the emission of gravitational waves as predicted by GR. RTB’s cosmic creation model incorporates GR, thus, any confirmation of GR puts RTB’s model on firmer ground.