Today’s New Reason To Believe

Previously Posted on March 13th, 2008 by Fazale ‘Fuz’ Rana, Ph.D.

Three New Studies Support Biblical Account of Humanity’s Creation

What’s the first thing that comes to mind when you think of the state of Kentucky? Horse racing? Wildcat basketball? The Louisville Slugger? Bluegrass music? What about burgoo?

Though most people probably haven’t heard about this spicy stew, it’s as much a part of the traditions of the Bluegrass State as the Kentucky Derby. Burgoo consists of a mixture of meats (beef, chicken, pork, mutton, and game animals, if available) and vegetables cooked (and re-cooked) in a large kettle over an open flame until all the flavors meld together. No two Burgoo recipes are the same. The preparation and consumption of Burgoo serves as a center piece for social gatherings. At times the entire community contributes the ingredients to make a large pot of stew.

Molecular anthropologists have recently concocted a burgoo of their own consisting of discoveries that turn the heat up on the support for the Out-of-Africa hypothesis of human origins, and with it, the biblical account of humanity’s beginnings.*

Out of Africa Hypothesis

In a nutshell, this model (also called the replacement model) maintains that modern humans evolved recently (about 100,000 years ago) in East Africa from a small hominid population and then migrated around the world to replace pre-existing hominids. Proponents believe that Homo neanderthalensis and Homo erectus are evolutionary side branches and dead ends.

Relative Proportion of Harmful Mutations in European and African Populations

One recent study, carried out by an international team, examined genetic variation in fifteen African American and twenty European Americans. These workers characterized genetic variability by examining single nucleotide polymorphisms (SNPs) and categorizing the DNA sequence differences as benign, possibly damaging, and probably damaging.

They noted that African Americans harbor a greater degree of SNP diversity than European Americans. Interestingly, European descendents have a greater proportion of harmful variations than people with an African ancestry.

These results find explanation if humanity arose in East Africa from a small population, and recently migrated into Europe through a genetic bottleneck. Bottlenecks result when a population drops to low levels and then recovers its numbers, or if a small subpopulation becomes separated from the main group and then later grows in size.

Genetic and Copy-Number Variation

Another study characterized the genetic variability of twenty-nine populations from around the world by monitoring 525,910 SNPs and 396 copy-number differences.

Again, the patterns of genetic variability noted in these two studies for people groups from around the world fit with the predictions of the Out-of-Africa hypothesis.

A third recently reported study focused on about 650,000 SNPs found in the genomes of 938 people representing 51 populations from around the world. The SNP data clustered into a number of groups displaying a geographical relationship that indicates an African origin of humanity and subsequent spread around the world.

Overwhelming Evidence for the Out-of-Africa Hypothesis

These three new research reports can be thrown into a large simmering kettle of studies that support the Out-of-Africa model. (For a detailed discussion of the myriad evidences in favor of the Out-of-Africa Hypothesis see the book Who Was Adam? Collectively, the consensus that emerges from this work indicates 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. Amazingly, studies using mitochondrial and Y chromosomal DNA markers trace humanity’s origin back to a single man and woman. These studies also indicate that humanity’s migration around the world began at or near the Middle East.

Though often presented and discussed within the context of the evolutionary paradigm, this model has profound biblical implications. In some respects, the Out-of-Africa hypothesis appears to be the biblical model awkwardly forced into the evolutionary framework, like an incorrect puzzle piece. If humanity’s genesis happened in the way described in Scripture, the genetic diversity patterns observed among people groups around the world would be very similar to those discovered by anthropologists. It looks as if Adam and Eve really existed, giving rise to all humanity.

Next week I will describe another study using DNA extracted from ancient head lice that also lends credence to the biblical account of humanity’s origin. I decided it would be best not to describe this work for now. I didn’t want to ruin anybody’s appetite.

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*These studies made science news headlines when first published. I discussed the scientific and biblical implications of this research on the February 22, 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 to this podcast is available through iTunes.

Keith McPherson

Keith McPherson received his Master of Science in Electrical Engineering from Georgia Institute of Technology in 1993, and currently works as an electrical engineer in Melbourne, FL, in the fields of communications and signal processing.

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Parts 1 through 4 of this series described such features as information-processing systems, Gray codes, even parity codes, and error-minimization techniques in biological systems. A fifth feature (not part of this series) observed an analogy of a feedback control system found in dairy cows.

What do these apparent analogies of design in nature mean? Are they really analogues and how do they relate to the popular watchmaker argument?

William Paley’s Watchmaker Argument¹

British natural theologian William Paley (1743-1805) is famous for his so-called watchmaker argument. Paley argued that in contrast to a stone, a watch found on a remote path implies a watchmaker. Unlike the stone, the watch could not be constructed by the forces of nature. Paley further argued that organisms are similar to a watch in complexity (in fact, more complex); therefore, a Divine Designer can be inferred. (See here for more details about William Paley and his watchmaker argument.)

A contemporary of Paley, Scottish philosopher David Hume (1711-1776) offered several criticisms of Paley’s argument. In Hume’s estimation, the analogical argument between organisms and a watch was weak. Hume argued that the objects being compared (living organisms and a watch) were too dissimilar to constitute a good analogy; therefore, Paley’s argument would not stand. (See here and here for more information on David Hume and his objections to the design argument.)

Modern critics have added further reasons for doubting the legitimacy of the watchmaker argument. B. C. Johnson has argued that Paley did not use a strict-enough criterion for identifying design. For Paley, design was evident when a system contained several parts “framed and put together for a purpose.” Johnson, in contrast, says “we can identify a thing as designed, even when we do not know its purpose, only if it resembles the things we make to express our purposes.”²

Logician Patrick J. Hurley demonstrates the appropriate use of analogy. To build a strong analogy, Hurley reasons that one must find sufficiently numerous and relevant attributes in both halves of the analogy to establish an analogical relationship that supports the conclusion drawn. An analogy is more firmly established when the analogous systems are diverse and abundant.³

Have these criteria been established in the examples considered in this series?

As an engineer I would submit these reasons in arguing for an undeniable “yes”:

the genetic system is, by any objective standard, an information-processing system in the same way that our modern communication systems are;

the genetic information-processing system uses discrete, symbolic alphabets and sequences just as our modern digital communication systems do;

numerous and diverse analogies directly resemble our own designs in information-processing and error-control coding;

we have found these analogies to be strict and robust between the domains— analogies that highlight techniques that are aimed to minimize errors and maximize information transfer;

we have seen analogies of Gray codes, parity codes, and even feedback control systems (see here);

the genetic code has been found to be highly optimized, literally one-in-a-million in terms of its error-minimization capacities, and the very same code simultaneously conforms to a specific and unique mathematical structure that enables, in addition, the existence of code(s) operating along the DNA strands;

statistical studies of actual DNA reveal a signature that further suggests that codes similar to the parity code may well be in operation along the DNA strands.

Thus, twenty-first century insight into the genetic system has helped settle the centuries-old debate. The analogies discussed meet the objections raised and standards set by Hume, Johnson, and Hurley. Paley’s watchmaker argument is indeed reinvigorated with this new and powerful evidence coming from the intersection of molecular biology and information theory.

This evidence buttresses the divine design component of RTB’s creation model and finds a comfortable spot within the worldview of Christian theism.

Notes/References:

1. See here for further information on Paley’s argument, and objections raised, in the context of molecular motors.

2. Fazale Rana, “Hume vs. Paley: These “Motors” Settle the Debate,” Facts for Faith, no. 2 (Q2 2000).

3. Fazale Rana, “Hume vs. Paley: These “Motors” Settle the Debate.”

Posted by Fazale ‘Fuz’ Rana, Ph.D.

Neanderthal Speech Gene May be Due to Contamination

Nobody really likes a potty mouth, including anthropologists. But it looks like these scientists will have to put up with “contaminated” language from Neanderthals, at least if the results of new work are valid. It appears as if the recovery of the so-called language gene from the remains of Neanderthals is not authentic, but instead may be due to contamination from human DNA.

The question of whether or not Neanderthals possessed language capacity has precipitated much controversy. Anatomical studies are ambiguous towards this end. (See Who Was Adam? for a detailed discussion.) To help resolve this issue a team from the Max Planck Institute turned to ancient DNA analysis to probe for the language gene in the Neanderthal genome.

In 2001, a research team from the United Kingdom reported that mutations in the FOXP2 gene cause severe language disorders. Presumably the FOXP2 protein plays a key role in controlling the development of brain and facial structures that support aspects of human language capacity.

An initial evolutionary analysis of the FOXP2 gene, conducted in 2002, indicated that the human variant arose about 200,000 years ago. Subsequent work, published later that year, placed the origin of the human FOXP2 gene at about 100,000 years ago. From an evolutionary standpoint, this is well after the time that humans and Neanderthals allegedly split from a common ancestor. Accordingly, Neanderthals should not possess a human-like FOXP2 gene and, therefore, language ability.

However, to everyone’s surprise, the team from the Max Planck Institute did isolate the human variant of the FOXP2 gene from a recently recovered Neanderthal specimen. This result was interpreted by some as evidence that Neanderthals had language. If so, it creates problems for the RTB human origins model, which predicts that Neanderthals and other hominids should behave in nonhuman ways, and, therefore, should not have the capacity for language.

Did Neanderthals possess language ability? At the time that the recovery of the Neanderthal language gene was announced I wrote:

The very real possibility exists that this result stems from contamination by human DNA. Clearly, the research team went to painstaking efforts to avoid contamination. Anthropologists suited up in clean room gowns and face masks to excavate the Neanderthal remains using sterilized tools. They designed the extraction protocol to avoid isolating any human DNA and ran the appropriate controls to ensure the Neanderthal DNA samples had no human contamination. In spite of these heroic efforts, the possibility of contamination cannot be ruled out. The team from the Max Planck Institute introduced contamination into the Neanderthal genome sample they were previously working with and wrongly interpreted this as evidence for human-Neanderthal interbreeding.

It looks like my initial assessment was right. A research team for the University of Chicago re-assessed the likelihood that Neanderthals possessed the human variant of FOXP2 by looking at the genetic variation associated with this gene among modern human populations. They concluded that the scenario proposed by the Max Planck workers—namely the human variant arose prior to the time that Neanderthal and human lineages diverged from a common ancestor—is inconsistent with the genetic patterns observed among modern humans. They also estimated that the human variant of FOXP2 arose about 42,000 years ago. This result falls in line with earlier estimates, which places the origin of the human variant between 100,000 and 200,000 years ago.

The Chicago scientists suggest two possible scenarios to explain the recovery of the human variant of the FOXP2 gene from Neanderthal remains. First, humans introduced the language gene into the Neanderthal gene pool through interbreeding. They assert that if low levels of interbreeding took place between humans and Neanderthals, this could account for the appearance of the human language gene in the Neanderthal genome. This conclusion is not well supported by other studies, which have failed to find any direct evidence for interbreeding.

The other possibility is that the DNA extracted from Neanderthals was contaminated with modern human DNA. Even though the Max Planck Institute scientists took every precaution to avoid contamination and even ran controls to ensure that their samples were free from contaminants, human DNA, which is ubiquitous, could have easily made its way into the sample. The team from the University of Chicago raises questions about the effectiveness of the control samples. They assert that the controls selected by the Max Planck team do not necessarily ensure contaminant-free Neanderthal DNA samples.

It is really beginning to look like Neanderthals didn’t have language capacity after all—just contaminated language. Now I’d like to know who’s going to volunteer to wash their mouths out with soap.