Today’s New Reason To Believe

Posted by Fazale ‘Fuz’ Rana, Ph.D.

New Research Supports Biblical View of Human Origins

I woke up this mornin’, feelin’ ‘round for my shoes. Know ‘bout ‘at I got these old walkin’ blues. - Robert Johnson, Walkin’ Blues

New research* by paleoanthropologists from Washington University and the Chinese Academy of Sciences indicates that modern humans were “feelin’ ‘round” for their shoes earlier than previously thought.

Anthropologists have great interest in the origin and natural history of footwear because it gives insight into a unique human cultural adaptation that assisted the spread of humanity around the world. Humans make use of footwear for protection in all environments and insulation in cold climates.

Unfortunately, footwear isn’t readily preserved in the archeological record because it is often made from soft material. The oldest footwear dates back to only about 10,000 years ago. [Work reported in 2005], however, demonstrated that foot anatomy can indirectly shed some light on the footwear use. Research indicates that toes become less robust when shoes are worn. Interestingly, other parts of the skeletal anatomy are unaffected. The 2005 study indicated that footwear was worn by modern humans about 30,000 years ago. Still, the question remains as to when the first footwear was worn.

A new opportunity to address the question surfaced recently with the discovery of modern human remains in a cave near Zhoukoudian, China. These remains date to about 40,000 years in age and include foot bones.

As part of this new study, the researchers compared the toe size of Europeans, Inuits, and Native Americans. For this study, the Europeans included in the sample made extensive use of footwear, the Inuits used crude footwear, and the Native Americans spent a significant time barefoot. They found that toe size inversely correlated with use of footwear, demonstrating the strength of this method to indirectly detect footwear use.

As part of the calibration, the scientists also examined the foot structure of Neanderthals and the near anatomically modern humans recovered in the Qafzeh-Skhul cave. The toes of both of these hominids were much more robust than even those of the Native Americans in the sample. It’s not likely that these creatures used shoes.

The researchers then determined that the toe size of the modern human remains recovered recently in China were consistent with extensive use of footwear. This find pushes the use of footwear back to 40,000 years ago.

This discovery fits well with the biblical account of human origins as embodied in the Reasons To Believe (RTB) creation model. In short, the RTB model for humanity’s beginnings asserts that God created Adam and Eve, in His image, through direct, miraculous intervention. (See Who Was Adam? for a detailed description of the model and the scientific support for it.)

This model regards the hominids found in the fossil record as animals also created by God’s direct involvement. Accordingly, these creatures existed for a time and then went extinct. RTB’s model considers the hominids to be remarkable creatures that walked erect, possessed some level of limited intelligence, and emotional capacity. This allowed these animals to employ crude tools and even adopt some level of ‘culture’ much like baboons, gorillas, and chimpanzees. While the RTB model posits that the hominids were created by God’s divine fiat, they were not spiritual beings, made in His image. The RTB model reserves this status exclusively for modern humans.

The RTB model treats the hominids as analogous to, but distinct from the great apes. Because of this, the RTB model predicts that anatomical, physiological, biochemical, and genetic similarities will exist among the hominids and modern humans to varying degrees. But since the hominids were not made in God’s image, they are expected to be clearly distinct from modern humans, particularly in their cognitive capacity, behavior, ‘technology,’ and ‘culture.’

The early appearance of footwear among modern humans—and the absence of any evidence for footwear usage among the hominids like Neanderthals and the near anatomically modern humans—match the predictions made by the RTB model. The use of footwear is a diagnostic for the image of God. This behavior requires advanced cognitive ability, creativity, and problem solving skills to recognize that covering the feet offers protection from harsh terrain and cold. Designing and manufacturing the tools to make footwear, too, reflects these same qualities.

Only humans made in God’s image get the “walkin’ blues.”

*This study made science news headlines when first published. I discussed the scientific and biblical implications of this research on the June 9, 2008 edition of our podcast, RTB’s Science News Flash. This podcast offers a unique Christian perspective on headline-grabbing discoveries. A free subscription is available through iTunes.

Posted by Fazale ‘Fuz’ Rana, Ph.D.

New Discovery Make Sense of Long Life Spans in Genesis 5 and 11

The other day I was shopping in the used CD section of my favorite local independent record store and I came across a compendium of songs by The Who.

Perhaps the one song most closely identified with this particular quartet of British rockers is “My Generation.” The song became an anthem for the rebellious British youth of the 1960s, decrying the older generation with the familiar chorus, “Hope I die before I get old.”

Now that I’m part of the older generation I can’t help thinking about the irony of the lyrics whenever I listen to this song. I hope I die when I’m really old. Amazingly, advances in the biology and the biochemistry of aging continue to make my hope a distinct possibility. And not only do these breakthroughs hold the promise for extending human life expectancy, they also provide a response to one of the greatest difficulties that skeptics have with the early chapters of Genesis: the long life spans of the patriarchs.

In the past decade or so, biomedical researchers have made significant progress toward comprehending aging. Scientists have identified a number of distinct biochemical mechanisms that play a role in senescence (aging). In most cases, when researchers subtly manipulate these processes, they can dramatically increase the life expectancy of model laboratory organisms, such as fruit flies, nematodes (worms), yeast, and mice. (See Who Was Adam? for a detailed description of some of these advances.)

Caloric Restriction

Scientists have discovered that caloric restriction extends life span. Reducing food intake by 30 to 70% can extend life expectancy by up to 40% for a wide range of organisms from yeast to mammals—assuming a nutritious diet. In humans, long-term calorie restriction reduces the risk of atherosclerosis.

Biochemists now have some understanding of how caloric restriction works. It appears that reduced intake of calories increases the activity of enzymes called sirtuins. This family of enzymes occurs in a wide range of organisms, including humans. Sirtuins become active inside the cell when the levels of nicotinamide adenine dinucleotide (NAD+) increase. The amount of this compound in the cell varies in response to the cell’s energy status. When in an energy-rich state, NAD+ levels fall off. When in an energy-poor state, NAD+ levels rise. Caloric restriction causes the cell to enter into an energy-poor state and, hence, ups the NAD+ levels and the sirtuin activity.

When sirtuins are active, genes become “turned off” or silenced. This presumably limits the “wear-and-tear” on DNA that normally takes place during the normal course of metabolism. The result is a delay in the aging process. Researchers note that when they inhibit sirtuin activity, the cell displays a biochemical profile that resembles those changes that take place during senescence.

Scientists have begun to manipulate sirtuin activity in an attempt to lengthen the life expectancy of model laboratory organisms. For example, investigators observe that when they add an additional sirtuin gene to yeast and nematodes, it extends their lifespan. Recently, a team of pharmacologists discovered a number of compounds that activate sirtuins in yeast and mimic the benefits of caloric restriction. One of the most potent, resveratrol, is found in red wine. When administered to yeast, this compound increases life expectancy by 70%! Follow-up studies demonstrated similar benefits for nematodes and fruit flies. Researchers have also extended the life span of mice that were fed high-fat diets by including resveratrol in their daily regime.

A new study extends our understanding of the impact of resveratrol action. Researchers fed three groups of mice different diets. One group received a control diet, one included low doses of resveratrol, and one a calorie-restricted diet. They evaluated the effects of these diets by monitoring gene expression profiles for the entire genome in a number of tissues. The team observed that the gene expression profiles for brain, cardiac, and skeletal muscles of mice that were fed resveratrol and a calorie-restricted diet overlapped. They also noted that both types of diets prevented changes in gene expression profiles associated with aging. They also noted that resveratrol feeding and reduced calories didn’t show age-related losses in cardiac function. This study provides the most comprehensive work to date documenting the positive effects of resveratrol in mammals, and opens the way for similar studies in humans.

This and other discoveries clearly indicate that aging results from rather subtle changes in cellular chemistry. (In this case, altering the activity level of sirtuins retards aging.) These changes are so slight that investigators studying the aging phenomenon are gaining hope and confidence that, in the near future, they will be able to partly interrupt the aging process by direct intervention through altered diet, drug treatment, and gene manipulation. It is not out of the question to extend human life expectancy to several hundred years—about the length of time the Bible claims that the patriarchs lived.

Biochemists’ success in altering the life span of model organisms in the laboratory and the encroaching ability to increase human life expectancy through biochemical manipulation makes the long life spans in Genesis 5 and 11 scientifically plausible. If humans can alter life spans, how much easier must it be for God to do so?

Varying sirtuin activity represents one possible method that God could have used to permit early humans to live several hundred years at the time of their creation, and then subtly adjust it to shorten life spans to no more than 120 years after the Flood event.

I may be singing along to “My Generation” for a long time.

Back to the used CD bins. Maybe I’ll find a Janis Joplin album. “Lord won’t you buy me a Mercedes Benz?”

Posted by Fazale ‘Fuz’ Rana, Ph.D.
[Originally posted on November 01, 2007]
Microbes and DNA from 8-Million-Year-Old Ice Shed Light on Origin-of-Life Question

We have a chest freezer in our garage that stores all the food that won’t fit in our kitchen refrigerator’s freezer. When it’s time to get something from the freezer, it usually comes from the top. It’s just too much work to dig down into the chest to get to a package of frozen food. Eventually stuff at the top finds its way down toward the bottom as food gets moved around and new items are added. On the rare occasion when somebody works up the motivation to “drill down” to the freezer’s bottom, they usually encounter barely recognizable items covered with a thick coating of frost or meat with severe freezer burn. Either way, nobody wants to eat the food from the bottom of the deep freezer. The good stuff is found at the top.

A team of scientists on a quest for “good stuff” recently drilled down into Earth’s deep freezer in the Mullins and Upper Beacon Valleys of Antarctica. And good stuff they found. The researchers recovered viable microbes and DNA from ice samples dated between 100,000 and 8 million years in age. It was like finding a popsicle in the bottom of the freezer.

This remarkable discovery bears important implications for the origin of life, calling into question the likelihood of life originating in comets or being delivered to Earth by these icy vehicles. Scientists are interested in looking for microbial life in the ancient ice sheets of Antarctica because such a discovery provides insight into the limits of biological activity and the preservation of life. It also provides a record of ancient life forms and a window to Earth’s past.

Scanning electron microscopy revealed the existence of filaments in the ice samples, which are taken as evidence for the presence of microorganisms. The researchers confirmed this interpretation by demonstrating metabolic activity in the ice through the uptake of radiolabeled amino acids and nucleotides and the breakdown of radiotagged glucose.

Based on these results, they successfully attempted to cultivate microbes from the ice. The researchers noted that the best stuff was found near the top of the Antarctic deep freezer. They were able to recover more microbes and a greater diversity of bugs in the younger ice samples.

The team also searched for community DNA in the ice. To undertake this endeavor they applied genomics techniques to enable direct sequencing of DNA isolated from the ice, without isolating and culturing the individual species of microbes.

They detected, based on DNA, 30 different types of microbes in the ice. The researchers noted diminished diversity in the older ice samples (as was the case for the metabolic studies and cultivation work).

They also characterized the fragment size of DNA in the ice and, once again, noted a greater degree of fragmentation and smaller fragments in the older ice samples. Using this data, the scientists estimated the half-life of the fragmentation process to be about 1.1 million years. The rate of breakdown indicates that cosmic radiation impinging on the ice is the primary driver of DNA fragmentation.

The relative instability of DNA in the ice and the loss in the viability of the microbes over the span of 8 million years makes it unlikely that life could arise in comets or be transported through interstellar space in these frozen bodies. Comets consist of frozen water along with dust and rock. The ice in Antarctica serves as a good model for the preservation of life and durability of biomolecules in comets. In fact, the ice in Antarctica represents the best-case scenario for survivability. Even though this region of Earth receives the highest dosage of cosmic radiation, it is not nearly as harsh an environment as interstellar space.

The short half-life of DNA and the limited viability of microbes after 8 million years in the ice of Antarctica makes it difficult to envision how life could emerge in comets of survive a journey of any length between star systems or within a solar system.

Now, to defrost my freezer. I hope I don’t find any originating life in the ice.