Today’s New Reason To Believe

David H. Rogstad, Ph.D.

Some Christians are critical of science whenever it comes in conflict with their interpretations of the Bible. They argue it is dangerous to hang any part of our theology on the “quicksand” of changing and uncertain science. Of course, the very nature of science is uncertainty. No scientist worth his salt will claim he knows anything with absolute certainty. However, there are degrees of certainty. Some claims are very well tested and consequently are referred to as laws of nature. Other claims are only tentative in nature, and are called theories that require further investigation and testing.

Newton’s description of how bodies move in response to external forces has been so well tested that we now refer to his work as laws of motion. On the other hand, we refer to the latest attempt to describe the physics of our universe, super strings, as a theory because it is probably incomplete and only beginning to be tested. But even Newton’s laws have been discovered to be incomplete. At the beginning of the 20th century scientists realized that these laws could not fully explain what was going on at the atomic level or in the realm of velocities near or at the speed of light. Hence quantum mechanics and relativity were born. Newtonian physics is adequate in the normal spheres of our experience, but these new refinements were necessary to deal with the extremes.

While Einstein’s general theory of relativity (GR) has been one of the most well tested theories in science, and should be classified as a law of physics, it is now being stretched to its limits. In the last few years astronomers have discovered the expansion of the universe is accelerating, implying that there is some additional force that must be accounted for. This can be achieved by modifying the equations of GR, either by adding an extra term, the so called “cosmological constant,” or by changing the form of the equations themselves involving higher-order curvature terms or extra dimensions, or by inventing some new exotic theory that approximates GR in the limit.

A recent paper published in Nature by L. Guzzo and colleagues presents observations that offer a test for the nature of cosmic acceleration that may be able to distinguish between its possible causes. They have made observations of more than 10,000 faint galaxies, all having redshifts on the order of z = 0.8 (a distance of 7 billion light-years). The team obtained the galaxies’ expansion and peculiar velocities (velocities clustered around their expansion velocities) to derive a growth rate parameter for the formation of galaxy clustering. They then compared the results with similar observations of galaxies and their clustering in the local area of our universe.

The astronomers created models for what they would expect from these comparisons, based on each of the different explanations for the cosmic acceleration. They concluded that the data are consistent with the standard GR including a cosmological constant, but not sufficiently accurate to distinguish between it and the other models. However, by extending their measurements over volumes about ten times larger, the astronomers expect to be able to tell which model best fits the data, thus gaining insight into the best theory of gravitation.

What we see here is the scientific method in action. A theory, no matter how much it has been tested, will make predictions that can be further tested. If the theory doesn’t fit the new observations, then the theory must be refined, or possibly completely replaced if some new paradigm is established. However, any new theory must be able to account for all the observations that were correctly predicted by the old theory. This process has proved to be slow and deliberate and tends toward refinements in existing theories rather than major paradigm shifts.

As scientists pursue the scientific method, they should be able to arrive closer to the truth about the physical aspects of God’s creation. Assuming this same process of testing and reflection is also applied to Scripture, we need never fear that science and faith will be in conflict. The work RTB expends on building a testable creation model is intended to faithfully apply this process to both science and our interpretations of the Bible.

Posted by Fazale ‘Fuz’ Rana, Ph.D.

Lice DNA Supports Biblical Account of Humanity’s Creation

Every parent dreads receiving a note from their children’s school announcing an outbreak of lice. Messages of this sort set in motion a series of unpleasantries for the child, parent, and sometimes the rest of the family.

Some anthropologists, however, take a certain delight in lice infestations. These obligate surface parasites, and their genetic variability, offer insight into human origins and the migration of the first people around the world.

Most scientists who study lice are interested in these parasites for biomedical reasons. For example, some choose to focus on the natural history of these disease-causing organisms. Learning about the timing and location of lice origins, the historical pattern of their spread, and consequently, the contemporary distribution of their genetic variation helps biomedical researchers understand how infectious diseases harbored by insects spread. This information can potentially lead to more effective public health programs and, in some cases, treatments.

In the process of studying the origin and natural history of human parasites, like lice, molecular geneticists have stumbled upon an exciting new way to characterize humanity’s origin and movements around the world. Researchers believe that the timing and location of the origin, as well as the spread, of disease-causing and disease-harboring pests around the world mirrors the timing and location of the origin and spread of humanity. As such, the worldwide genetic variation of these infectious agents can be used in the same way that molecular anthropologists use human genetic variation to gain understanding of human prehistory.

A remarkable study on the global circulation of head lice illustrates how this creature can be used to track the spread of humanity around the world.*

There are three types of head lice (based on genetic fingerprints) distributed around the world: types A, B, and C. Type A is found throughout the world. Type B occurs in North and South America, and Europe. Type C is rare and geographically restricted to Ethiopia and Nepal.

Some investigations posit that Type A head lice established its association with modern humans in Africa shortly after the first people appeared. Type B originated in Europe after humanity spread into Asia and then Europe. Accordingly, Type B head lice appeared in the New World when Europeans colonized the Americas. If this model is correct, then Native Americans would have carried Type A head lice with them when they originally migrated into the Americas from Asia.

Researchers recognized a unique opportunity to test this model with the discovery of pre-Columbian mummies in Peru, dating to about 10,000 years in age, well before the Spanish and Portuguese arrived.

Anthropologists were able to recover the remains of ancient lice from the hair of the mummy. They then successfully extracted DNA from the lice specimens, then amplified and sequenced it. The lice possessed the Type A DNA fingerprint. This result means that the first immigrants into the Americas most likely carried the same genetic version of lice as the first humans in Africa. Type B lice must have been introduced by European settlers.

The natural history of lice matches the expected pattern of the Out-of-Africa hypothesis for human origins. Though often presented and discussed within the context of the evolutionary paradigm, this model has profound biblical implications. This hypothesis, which is substantiated by numerous studies, maintains that humanity originated recently (about 100,000 years ago) from East Africa (near the location theologians ascribed to the Garden of Eden) from a small population. Studies using mitochondrial and Y chromosomal DNA markers trace humanity’s origin back to a single man and woman. The genetic data also indicate that humanity’s migration around the world began at or near the Middle East.

If humanity’s genesis happened in the way described in Scripture, the genetic diversity patterns observed among international people groups would be very similar to those discovered by anthropologists. It looks as if Adam and Eve really existed, giving rise to all humanity.

For a detailed discussion of the myriad evidence in favor of the Out-of-Africa hypothesis and the use of parasites to characterize the origin of humanity see my book Who Was Adam?

*This study made science news headlines when first published. I discussed the scientific and biblical implications of this research on the February 11, 2008 edition of our new podcast, RTB’s Science News Flash. This podcast offers a unique Christian perspective on headline-grabbing discoveries. A free subscription is available through iTunes.

By Katie Galloway

[Katie Galloway is an RTB volunteer apologist. She is completing her PhD at Caltech in Chemical Engineering with an emphasis in biological systems.]

Imagine putting tons of super glue on your hands and feet and trying to climb the Empire State Building like Spider-man. Your dynamic display of agility doesn’t get you too far. You’re stuck! That’s because the chemical bonds between the sticky glue and the building surface are stronger than the force of your weight. If the bonds on your feet and hands hold your weight, you will have to pull off with at least a fourth the force of your weight for each new grip-not a very satisfying solution if you have to climb 102 stories to the top. And by the way, you will probably have to reapply glue for each step since the glue will not stay sticky. Clearly this represents a poor design strategy for scaling sheer surfaces-so how do geckos do it?

Geckos have the amazing ability to adhere to sheer surfaces, but it’s their capacity to control their adhesion and not stay stuck that allows them to run straight up walls. Their feet aren’t sticky or else they would get stuck just like you and your super glue. Instead, geckos adhere to surfaces using spatulae composed of billions of setae, hard bristle structures that look like split-ends gone crazy. Adhesion is promoted via Van der Waals forces, the sum of the attractive intermolecular interactions between the surface and the setae.

To put Van der Waals forces into effect, the gecko employs shear force (the force applied parallel to the surface) to get its setae in close contact with the surface. By regulating the shear force, the gecko controls the area of the setae in contact with the surface of a tree or wall. The more force applied, the more the otherwise perpendicular setae bend, creating a larger surface area for the Van der Waals interactions that create adhesion. Fortunately, this process is reversible. To take another step, the gecko reduces (unloads) the shear force on the foot so the setae are no longer induced to bend. The contact area between the gecko’s foot and the wall decreases until the gecko can easily lift and replace the foot.

To see this principle in action, slide the tips of your fingers down a window. They slide pretty easily, but when you put your entire hand on the glass and pull down you encounter greater resistance. This is due to friction created by the interaction of atoms in the glass with atoms in your hand. With only your fingertips, the small area of contact results in a small frictional force. More Van der Waals forces are generated with the larger surface area of your hand, requiring more sliding force to overcome. Additionally, you can observe that even more force is required to slide your hand as you increase the pressure. This is because increasing the pressure puts more of your hand in contact with the glass, creating more intermolecular bonds. So why can’t you scale the Empire State Building like a gecko?

From your perspective, it appears that your hand is in complete contact with the glass, but in actuality, very little of your hand is touching the surface. Due to the roughness of the glass and your hand, the contact area is still relatively small, and the atoms close enough for Van der Waals interactions number very few. Putting more pressure on the surface achieves greater contact, but it also causes you to push away from the wall, which is the opposite of the direction you want to go. Without flexible setae, humans do not have much control over their degree of contact with surfaces like glass or the sides of buildings. Our ability to enhance or reduce this contact area without pushing off the surface is very limited, unlike the wieldy gecko.

While humans lack natural setae, wings, sonar, and a host of other biologically inspired devices, we are endowed with a set of powerful tools to unlock the mysteries of Earth’s creatures and harvest knowledge of the natural realm to benefit mankind. As reported in the January 30, 2008, issue of Science Daily, researchers at UC Berkeley put their curiosity and brains to work in designing a gecko-mimetic tape that adheres when loaded with shear force, yet can be easily removed from a surface without leaving a residue¹. Synthetic stiff polymer microfiber arrays were fabricated from polypropylene. Forty-two million stiff plastic fibres 20um in length and only 0.6 um in diameter were arranged in 1 cm². Two cm² of this tape were able to hold up 400 g, or nearly 1 pound. The team from Berkeley reported that:

“In the absence of shear forces, these fibres show minimal normal adhesion. However, sliding parallel to the substrate with a spherical probe produces a frictional adhesion effect which is not seen in the flat control.”²

By harnessing the geckos’ mechanical strategy to induce Van der Waal interactions via shear force, the researchers demonstrated that stiff polymers can be used to attain sliding-induced adhesion. While this tape marks a step forward for gecko-inspired synthetic adhesives (GSA)gecko-inspired adhesives, more research into a system for nonfouling adhesives is necessary before anyone “Spider-mans” up a skyscraper.

Scientists have been studying gecko adhesion for decades, but even before formal science picked up interest, the Bible was cluing in readers to the gecko’s unique abilities. In Proverbs 30:24-28, the Bible says, “A lizard can be caught with the hand, yet it is found in kings’ palaces.” Today we have greater insight into how these little guys can be so stealthy!

References:

¹ J. Lee, C. Majidi, B. Schubert, and R. Fearing, “ Sliding induced adhesion of stiff polymer microfiber arrays: 1. Macroscale behaviour,” Journal of the Royal Society, Interface

² B. Schubert, J. Lee, C. Majidi, and R. Fearing, “Sliding induced adhesion of stiff polymer microfiber arrays: 2. Microscale behaviour,” Journal of the Royal Society, Interface