In the last article I discussed the credibility of two key ideas related to evolutionary science, namely mutations and natural selection. As it stands, it is generally recognized that nothing in biology makes sense outside of acceptance of these two processes, and more importantly they are well documented. In this article I am going to direct our attention to the most significant development in biology over the past few decades. It is a development that has fundamentally changed the conversation.
First off, it is important to recognize that throughout most of history biological knowledge has generally been descriptive and analog. In general the process of acquiring that knowledge has started with a hypothesis and then progressed to a theory, all the while supported by data derived by dissecting, categorizing, along with comparison of body plans. For the past several hundred years this accumulating data has been informed by a study of the geologic column and the fossil record that it displays. Clearly this approach has provided a lot of useful information, but it has also taken place at a level of tentativeness that would not exist if biology operated on a more quantitative basis. That has now changed. With the unraveling of the DNA structure, it has become increasingly possible to explore the secrets of the DNA code itself. With the recent completion of the genome map for humans and a number of other species, the methodology has dramatically transformed biology from a qualitative science to that of a quantitative and computational science. In short, the genetic code is a complex information system and can be thought of as a digital data recording and processing technique. Most significantly, it is now being studied on those terms.
The old argument many Adventists use in opposing evolutionary theory, has often been based on “missing links.” Such argument is no longer relevant. For one thing many transitional forms have been found, including the fossil remains of a number of key hominids (and in the case of the Neanderthals, a portion of their DNA, while in the case of the Denisovans a complete genome). More importantly the quantitative tools afforded by science's expanding knowledge of DNA now give us data that renders most of these old lines of argumentation moot. In short, the debate has changed—and it has changed fundamentally.
In the pre-computer era, Claude Shannon, the father of modern information theory, proposed that communication errors could be overcome by building in sufficient redundancy and by proceeding in a “segregated, linear, and digital fashion.” This idea is, in fact, foundational to all computer technology and to the binary code that developed around it consisting of just two coding elements—a positive represented by the number 1 and a non-positive represented by 0. From the arrangement of these 1s and 0s, humans have managed to create all the powerful and precise activities that computers are known for, including programmed decision-making and other extraordinary capacities that have transformed human life in so many ways. For a visual map of this code take a look at the alpha http://www.convertbinary.com/alphabet.php and numeric http://www.convertbinary.com/numbers.php arrangement of the binary code as it will give you some idea what you might expect with the DNA code.
As scientific understanding of DNA came to maturity it became clear that it is at its essence, a digital code that is not unlike computer software code with four-nucleotides. That DNA four-nucleotide code for humans is a little over 3 billion base pairs in length, and generally goes by the abbreviated form: A-T-G-C. These nucleotides are grouped into approximately 23,000 genes, and 46 paired chromosomes. They are the code of life, though the exact definition of life is still being worked on. Clearly it is much more sophisticated and complex than anything that humans have created with binary computer code, but it does have some remarkable similarities.
Let’s suppose we were to write a message using binary code. In the process let’s assume that one or more of those 0s and 1s of code got mixed up. Clearly the receiver of the instructions will need to translate the message into English (or whatever language that is being used) in order to understand the instructions. The end result might very well be a set of instructions where say one alphabetic letter has been substituted for another. The receiver might end up with instructions that when translated were still understandable, or an instruction not actually intended, or one that makes no useful sense. This is analogous to what happens with mutations where the genetic code has become scrambled. Sometimes it is just one nucleotide letter that has been affected—sometimes more. Sometimes it will be critical to the overall integrity of the organism, and sometimes not. The important point in all of this is, that biology can now be analyzed in quantitative ways. It has become transformed it into an objective science.
Hubert Yockey, a prominent physicist from the University of California, Berkeley, CA, author of the book Information Theory, Evolution, and the Origin of Life, states: “information, transcription, translation, code, redundancy, synonymous, messenger, editing, and proofreading are all appropriate terms in biology. They take their meaning from information theory and are not synonyms, metaphors, or analogies.” He further notes that the existence of the biological genome and its supporting code divides living organisms from nonliving matter. He concludes, “There is nothing in [the realm of physics and chemistry] that remotely resembles reactions being determined by a sequence and codes between sequences.
Science now understands that the digital sequence of nucleotides in DNA is the software of life and that it controls all biological processes. It is coded to maintain the integrity of the organism in real time, but also provides a wealth of information about current relationships as well as ancient ancestral ones. The sequences of nucleotides or amino acids that carry the genetic message have explicit specificity. As Yockey notes, by employing information theory the message in the genes can be explored based on a comparison between the genetics of organisms, and that exploration can now be undertaken with the same quantifiable accuracy that is typical of astronomy, physics and chemistry. 
One of the most important points for readers to grasp is that DNA is now being sequenced for a wide spectrum of organisms ranging from bacteria and viruses, to humans and other species. Thus the relationship of all organisms can be determined based on the amount of similarity, and the degree of closeness in terms of DNA sequenced information that is shared. It is now possible to make comparisons, in numerical terms, between all these organisms, comparisons that go well beyond mere armchair speculation.
Naturally some will question whether differing species are the product of an Intelligent Designer who merely used common body plans to create distinctive forms of biology, or whether the degree of separation is one of coding. As to the first of these two possibilities it is important to remember that science, proceeding on the basis of methodological naturalism will never be equipped to fully address purposeful design considerations, though the question of common descent may eventually be resolvable with some degree of certitude. Conclusions on descent would be based simply on a more complete understanding of the DNA code, how it modifies, and whether it contains certain limits that are not currently understood.
At this point no one really knows where this new quantitative tool will lead given biological complexity and the relatively new era of DNA genetic research. It will take time to sort out the precise details; however, science now has a reliable mechanism that will allow it to explore biology with a high degree of objectivity and in detail at a level never before seen. There will likely be many surprises that await science. Unfortunately there are also likely surprises that will challenge Adventist sensitivities. The question that remains is whether Adventists collectively are open to receiving new light?
In the next article we will take a look at the most controversial aspect of evolution, that being the idea of common descent. Some readers have already made up their minds without having looked at the evidence. The next article will actually look at some of the key pieces of evidence that suggest common descent.
1. Information Theory, Evolution, and the Origin of Life, Hubert P. Yockey, (Cambridge University Press, 2005)
2. The Rough Guide to Genes and Cloning, Jess Buxton & Jon Turney (Penguin Books, 2005)
3. DNA: The Secret of Life, James D. Watson, Winner of the Nobel Prize for his role in uncovering the secrets of the double helix (Alfred A. Knopf, 2006)
See Hubert P. Yockey, Information Theory, Evolution, and the Origin of Life (Cambridge University Press, 2005), p. ix
These letters representing four chemical units that make up the nucleotide bases of DNA: (A) adenine, (T) thymine, (G) guanine, (C) cytosine
See Hubert P. Yockey, Information Theory, Evolution, and the Origin of Life (Cambridge University Press) 2005, p. 6.
This is a companion discussion topic for the original entry at http://spectrummagazine.org/node/5168