Evolution, the genetic code, and ‘message theory’: A response to Walter Remine
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By Nicholas Covington
Article ID: 1322
[Editor's note: This article and its comments are here in entirety, but a continuing response by the author can be found at this link.]
This article is a response to a blog post at Uncommon Descent by Walter Remine[1]. I will begin by quoting part of his essay:
“Life is unified by an abundance of complex biochemical features possessed by all, or virtually all life. Such features are known as biologic universals. The list includes:
DNA, RNA, a triplet-nucleotide genetic code, and the method of translation of the genetic code into sequences of amino-acids in proteins. Proteins constructed of left-handed alpha-bonded amino-acids, the same set of 20 amino-acids (out of several thousand amino-acids that exist). The lipid bilayer construction of cell membranes. Adenosine triphosphate, biotin, riboflavin, hemes, pyridoxin, vitamins K and B12, and folic acid implement metabolic processes everywhere.
For a given complex trait, there are rare, very minor variations away from the standard form. For example, there is now known about two dozen microorganisms that have slight variations on the universal genetic code.”
I have no problem with this. I do have a problem with Remine’s further comments:
“Leading evolutionists acknowledge that each of the biologic universals is too complex to have been in the first life – nothing even remotely like known life could have originated by known natural processes aided by chance and the available time. The probability is staggeringly too small, even on the scale of the universe. This should have falsified evolution, but instead evolutionists compensated by making their theory unfalsifiable. That is, without any serious evidence, evolutionists now make three bold, untestable, unfalsifiable, unscientific assertions:
1. There exists an infinitude (a very large number) of other biochemistries suitable for life. Evolutionists make this unscientific assertion in order to artificially increase the likelihood of life arising by chance. Evolutionists acknowledge the chance origin of any known lifeform is vastly too unlikely, but they claim the chance origin of some lifeform (when allowing for the infinitude of other possible lifeforms) is quite likely. They say there is nothing ’special’ about Earthly lifeforms, instead life just happened by chance upon the type of life we see on Earth.
2. The first lifeforms were vastly simpler than any life known today. The first lifeforms possessed essentially none of the biologic universals.
3. Many evolutionists further assert that life may have originated more than once on Earth, perhaps many times.”
The first life by definition would have to have structures to perform things like replication, metabolic processes, etc. Although it is theoretically possible for something to reproduce, and break down energy without having the specific structures that our type of life does, if all life is descended from one primordial organism then the structures performing these functions could not have changed much as we’ll discuss further on.
As for Remine’s allegation that evolutionists make “three unscientific assertions”: I would love to see a source for point 1 – “There exists an infinitude of other biochemistries suitable for life”, as I have never heard any evolutionist say anything like that. Point 2 – “The first lifeforms were vastly simpler than any life known today” – is false because the first life form would have had several of the biologic universals, as I will explain later. As for point 3 – “Life may have originated more than once on Earth” – it is a possibility that life originated multiple times, but I know of no one who insists that this is the case. Once again, no source is cited. Remine says:
“With those assertions in mind, if evolution predicts anything clearly on this matter, it predicts the opposite of what we observe – it predicts that countless lifeforms lacking all, or most, of the biologic universals must have existed on this planet.”
Once again this is false. Remine continues:
“Since we have not found those other lifeforms, it again appears evolutionary theory is falsified. And once again evolutionists compensate by adding another untestable, unfalsifiable, unscientific assertion. They assert (again without serious evidence) that the missing lifeforms all went extinct because those lifeforms – whatever they were – are not suited to survival anywhere in the Earth’s current conditions. Evolutionists possess no such knowledge negating the survivability of unknown lifeforms.”
Not true. We know that DNA and protein based life can survive practically anywhere (from boiling volcanic vents to acidic caves) so this type of life could have easily seeped into every nook and cranny on Earth and outcompeted the more primitive or less efficient forms of life. Remine goes on:
“For further insight, assume the evolutionists’ story: (a) the last universal common ancestor contained the biologic universals, and (b) the other lifeforms went extinct. Under those assumptions, there is still no coherent reason why two modern organisms – as different as yeast and elephant – should share any similarities. By the evolutionists’ reckoning, these two organisms are separated by at least two billion years of evolution (one billion years in each direction since divergence), and perhaps as much as three times that figure. Under assertion 1 (above) there is no reason yeast and elephant should still share the same biologic universals. Given this enormous amount of time, and the alleged evolutionary proclivity for change, and an infinitude of other biochemistries suitable for life, there is no reason yeast and elephants should still show the same biochemistry. Evolutionists are caught in a contradiction of their own manufactured storytelling. In evolution, everything changes – except the things they conveniently claim didn’t change.”
This is false. If all living things come from one common ancestor, then there must be a finely graded chain of viable intermediates from each living species back to the primordial “mother” species. This implies severe constraints on the amount of change that could take place in how these organisms reproduce (on the molecular level). To show why, allow me to explain with an excerpt from my book “Atheism and Naturalism” concerning why Evolution predicts a universal (or near universal) genetic code[2]:
“One of the most remarkable discoveries in Biology was James Watson and Francis Crick’s discovery of the secret of life: DNA. DNA acts a storage system for genetic information. Combinations of DNA letters spell out precisely what protein is to be produced. Now, the fact that all life uses DNA to store protein-making information is not surprising. But it is peculiar that the actual code is almost exactly the same throughout all living organisms. Peculiar, that is, if you do not accept Evolutionary Theory. In nearly all living things the genetic code is the same old same old: The letters UCU code for the amino acid Serine, the letters CAU code for Histidine, and so on.
Why should this be? Well, if a change occurred so that a codon (the three letters of an amino acid’s genetic code) was suddenly “reassigned” and began coding as some other amino acid, it would very likely change every protein that an organism had, and such a radical change would almost certainly mean that the organism would be far less fit than other other members of the species (if such a change was not fatal). So any radical changes to the genetic code (such as these) are essentially impossible.
However, there is an exception[3]: In 1963, long before the data was in on how universal the genetic code was, Francis Crick speculated that there may be certain circumstances that lead to minor alterations in the genetic code[4]. Suppose that some codon is a victim of “biased mutation”: For whatever reason, whenever there is the codon “UUU” it usually mutates into another codon, like “UUC” which codes for the same amino acid[5] (thus causing no change in protein construction, and so no change in the adult organism). The codon “UUU” would become exceedingly rare in the organism’s genome, and it would then be possible for it to be “reassigned” to code for some other amino acid. Of course, this scenario depends on so many specific conditions that it should be rare, but since there are millions of different species on Earth we can expect it to have happened before.
This leads to a clean prediction: If all living things are descended from one primordial organism, then the genetic code should be the same for all living things (because changes to the code will very probably be lethal), with the possibility of a few minor exceptions which evolved as described above. As it turns out, this is correct: Time and again, the same codons code for the same amino acids, with some very rare exceptions in which a codon codes for a different amino acid in separate species[6].”
The theory of common descent states that all living things are the descendants of one original living thing[7]. To be alive means to be able to replicate and evolve, and have some form of metabolism[8]. Metabolism requires enzymes. Enzymes are always made of protein (or are based on protein)[9]. To make proteins, you need a genetic code to store information about how to build these molecules. So if all organisms are descended from the same original organism, they should have inherited the genetic code of this organism. All organisms should have the same genetic code (with a possibility of a rare variation here and there). Since we know this to be the case, common descent is true.
I’d like to now take a look at Walter Remine’s proposed alternative, “Message Theory”. According to Remine, his theory:
“…claims life is designed to look like the product of one designer. If you could find any natural living organism (terrestrial, or extraterrestrial) that is not indelibly unified together with our system of life, then Message Theory would be falsified: For example, a lifeform that uses silicon-based chemistry instead of carbon-based chemistry. Countless other examples can be envisioned; indeed these are routinely envisioned, and hoped for, by evolutionists. Message Theory is testable science.”
If life is the product of one designer (and designed to reflect such), then why are the fish and the whale designed to swim differently? The fish moves its tail from side to side when swimming, but the whale moves its tail up and down, just as other land mammals move their bodies up and down through the water. This difference is easily explained if whales are descended from land mammals, but if whales and fish were designed by someone who wanted to show that he designed both of them, why not design the whale to swim as fish do?
Before I conclude this article, I want to address an objection that could be made against my case: What if we broadened the definition of common descent so that the common ancestor of all life may not have been a living thing, but just a simple, self-replicating molecule (as many scientists believe life evolved from)? Then it would be possible for this replicator to split into many evolutionary lineages each of which separately evolve a genetic code.
I think that this is possible, although it would not be the best explanation for what we observe today. Here are the five possibilities as I see them:
1) Common Descent from a living Common Ancestor: predicts universal genetic code.
2) Common Descent from a non-living Common Ancestor: since the genetic code is just a system of information storage, it need not be based on DNA, and even if it did, the DNA codons do not have to code for the same amino acids (we know this because there are small variations in the genetic code). Since we know that convergent evolution[10] often produces different outcomes (as is evident in the example of the whale and fish) we could expect to observe many genetic codes amongst living things.
3) Multiple Origins of Life with many Evolutionary Lineages still alive today: predicts that there must be many genetic codes (for the reasons discussed above).
4) One Intelligent Designer of all living things who designed them all the same: fails to explain slight variations in the genetic code, also fails to explain things usually interpreted as convergent evolution (such as the whale/fish example, or the differences in bird and bat wings).
5) Many Intelligent Designers who designed things differently: fails to explain why there is so much similarity in the way things are built.
Common Descent from a living Common Ancestor predicts exactly what we see, while the other possibilities do not. Even if we bend the definition of common ancestry to include the possibility of descent from a non-living molecule, common descent is still the best explanation because it is the only explanation that predicts exactly what we observe.
One last thing: The genetic code may be used to test evolution. For example, evolutionists hold that human beings share a common ancestor with primates. Remove this prediction, and evolutionary theory becomes meaningless. If humans share a common ancestor with all primates, then they should have the same or very similar genetic code. We can say the same with regard to many other groups of plants and animals: Reptiles and mammals must share a common ancestor, therefore they must have the same genetic code. Even if we allow that some organisms on Earth are descended from different lineages (for instance, we could say that plants are descended from a different lineage than animals), the fact would remain that evolutionary theory requires major groups to share the same genetic code. If they did not, then all anatomical, biogeographic, and fossil evidence supporting their shared ancestry would be an illusion, and evolutionary theory itself would be useless.
REFERENCES
[1] http://www.uncommondescent.com/evolution/message-theory-%E2%80%93-a-testable-id-alternative-to-darwinism-%E2%80%93-part-4/
Accessed 5/10/09
[2] See Pages 147-148, Nicholas Covington, “Atheism and Naturalism”, Lulu, 2009. Available for Purchase at:
http://www.lulu.com/content/paperback-book/atheism-and-naturalism/6307598
[3] For simplification I only mentioned one way that the genetic code can evolve. However, there are other ways, though they are very limited in how they can change the code. See Koonin EV and Novozhilov AS “Origin and Evolution of the Genetic Code: The Universal Enigma”, Pages 4-5. Accessed at:
http://arxiv.org/abs/0807.4749v2
Accessed 5/12/09
[4] Crick, F. H. C. “The recent excitement in the coding problem”. Prog. Nucleic Acids 1, 163–217 (1963).
This was also predicted in HINEGARDNER RT, ENGELBERG J., “RATIONALE FOR A UNIVERSAL GENETIC CODE.” Science. 1963 Nov 22;142:1083-5.
The Abstract reads:
“A mutation in the genetic code would place new amino acids in certain loci and entirely eliminate amino acids from other loci of practically all proteins in an organism. It is reasonable to postulate that mutations of this kind cannot supplant the original code. The genetic code, once established, would therefore remain invariant.”
[5] Page 45, John Maynard Smith and Eors Szathmary, The Origins of Life, Oxford University Press, 2000.
[6] RD Knight, SJ Freeland, LF Landweber, “Rewiring the Keyboard: The Evolvability of the Genetic Code” Nature Reviews: Genetics, 2, 49-58 (2001).
[7] http://www.talkorigins.org/faqs/comdesc/default.html#common_descent
Accessed 5/10/09
[8] http://www.una.edu/faculty/pgdavison/BI%20101/Overview%20Fall%202004.htm
Accessed 5/10/09
[9] http://www.medterms.com/script/main/art.asp?articlekey=3266
Accessed 5/10/09
[10] http://www.pbs.org/wgbh/evolution/library/01/4/l_014_01.html
Accessed 5/10/09
Other articles related to this topic:
- Was life on Earth an alien creation? A critical look at “directed panspermia”
- Evolution makes testable predictions
- A review of “On the Origin of Species” by Charles Darwin
- Macro-evolution observed in the laboratory
- Evolutionary science and creationism: A skeptical response to Duane Gish’s “Creation Scientists Answer Their Critics”
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