Posted by jlwile on May 25, 2010
I want to discuss more about Dr. Peter Borger’s excellent posts at Creation Ministries International’s website, because I really think he is onto something. As anyone who is remotely familiar with young-earth creationism knows, God designed specific kinds of organisms. Those organisms were created with the ability to adapt to changing environments, so the organisms we see today are those that descended from the various created kinds. The scientific pursuit dedicated to determining exactly what kinds of organisms were made and how the organisms we see today are related to those created kinds of organisms is called baraminology. This word comes from the Hebrew words bara, which means “created,” and min, which means “kind.”
So how did God give these created kinds the ability to adapt to changing conditions? According to Dr. Borger, He gave them baranomes, which are:
pluripotent, undifferentiated genomes with an intrinsic ability for rapid adaptation and speciation. Baranomes are genomes that contained an excess of genes and variation-inducing genetic elements, and the law of natural preservation shaped individual populations of genomes according to what part of the baranome was used in a particular environment.
In other words, the genome of each created organism was full of many genes, some of which the organism didn’t even need. These “excess genes,” as well as changes produced by the built-in elements that promote genetic change, were then acted on by natural selection (which he calls “natural preservation”) to produce the various organisms that we see today. In the article I linked above, Dr. Borger produces some powerful evidence to support this idea.
Consider, for example, the genetic analysis of different species of yeast. A very popular study among evolutionists1 showed that in five species of yeast, only baker’s yeast (Saccharomyces cerevisiae) had a gene (called BSC4) that coded for a protein involved in DNA repair. Based on their analysis, the authors of the paper suggested that this is because the gene was added to the genome of S. cerevisiae through random mutation of a non-coding region of DNA. Thus, according to the authors, this was evidence that novel genes (new information) can be added to the genome by mutation and natural selection.
In his paper, Dr. Borger shows why this conclusion is wrong. In fact, he shows the DNA regions in three other yeast species that clearly represent interrupted and inactivated forms of the gene found in baker’s yeast. Thus, rather than this gene appearing in S. cerevisiae, it was originally part of the yeast baranome, and it degraded in the other species of yeast but survived in S. cerevisiae. It degraded in the other species of yeast because it provided no survival advantage in their environments.
Probably the most intriguing evidence present in Dr. Borger’s paper is an in-depth analysis of the types of photosynthesis in yellowtops, which are sunflowers from the genus Flaveria. If you aren’t familiar with the details of photosynthesis, you might be surprised to learn that there are actually three different means by which plants engage in this process, and they revolve around how the plant takes in carbon dioxide.
The most popular (and most direct) form of photosynthesis is called C3 photosynthesis. In this process, carbon dioxide is taken in by the leaf and reacted with a molecule (RuBP) that contains five carbons. This reaction produces two three-carbon molecules that continue the process of photosynthesis. The “3″ in “C3″ refers to the fact that the carbon dioxide is used to produce two three-carbon molecules.
While this is the most direct way to use carbon dioxide in the process of photosynthesis, there is a potential drawback. The protein that controls the reaction of RuBP with carbon dioxide can also use oxygen, which will not help the photosynthesis process. This is normally not a problem because the protein is much more sensitive to carbon dioxide than it is to oxygen. However, when it gets hot, the levels of carbon dioxide in the leaf decrease, and as a result, the reaction with oxygen becomes more likely. This makes photosynthesis much less efficient.
To overcome this problem, C4 photosynthesis operates in a slightly different way. Instead of directly reacting carbon dioxide with RuBP, a C4 plant reacts carbon dioxide with a three-carbon molecule to produce a four-carbon molecule. The “4″ in “C4″ refers to that four-carbon molecule. The four-carbon molecule is then shuttled to a thick-walled cell where it is broken down into the original three-carbon molecule and carbon dioxide. The carbon dioxide is then reacted with RuBP (just as it happens in C3 plants) to continue photosynthesis.
Why bother to use carbon dioxide to make a four-carbon molecule if it is going to have to be broken down later on? Because it can be broken down in a different place, where the carbon dioxide can be concentrated. Thus, a C4 plant uses the four-carbon molecule as a vehicle to move the carbon dioxide to a place where it can be concentrated. This gets rid of the problem associated with the protein liking oxygen. C4 plants keep that protein in a place where the carbon dioxide levels are kept high.
As you might expect, then, C4 plants do better than C3 plants in hot conditions. However, in mild conditions, C3 plants do better, because their photosynthesis is more direct. For example, if you have a lawn in which crabgrass is a problem, you have seen this effect. In the spring, you don’t see much crabgrass, but during the hot summer months, you see a lot of it. That’s because typical lawn grasses are C3 plants, but crabgrass is a C4 plant. So in the spring, lawn grass is favored, but in the hot summer, crabgrass is favored.
The third kind of photosynthesis, CAM, is best for hot, dry climates. It isn’t really relevant to this discussion, so I won’t give you the details.
If you had trouble following the C3/C4 discussion, that’s okay. Even if you didn’t understand the entire thing, it should be clear that C4 photosynthesis requires more genes than C3 photosynthesis. After all, in addition to all the genes involved with incorporating carbon dioxide into photosynthesis, C4 plants would need the genes associated with making the four-carbon molecule, shuttling it to a different cell, and breaking it down to get the carbon dioxide.
Well, in a study on several species of yellowtops,2 it was shown that despite the fact that all of the species belong to the same genus (Flaveria), some were C3 plants, some were C4 plants, and some were able to do both C3 and C4 photosynthesis.
According to the study, this is the result of macroevolutionary transitions between C3 photosynthesis and C4 photosynthesis. However, Dr. Borger’s interpretation is that the baranome of the yellowtop kind had the genes for both systems. In areas where there weren’t a lot of hot days, C4 photosynthesis was not very beneficial, so the genes associated with it decayed away in the genome of species in those areas. In areas where there weren’t a lot of mild days in the growing season, C3 photosynthesis didn’t contribute much to survivability, and those genes decayed away in species that occupied such areas. In areas where there are both mild and hot days, both systems are beneficial, so they are both still in the genome.
The advantage to Dr. Borger’s explanation of the genetics of yellowtops is that it doesn’t depend on any mysterious chemistry. To evolve from C3 to C4 photosynthesis requires the adding of new information into a genome. There is no known mechanism by which this can happen, so to believe the authors of the study, you have to believe in a mystical mechanism that currently doesn’t seem possible. To believe in Dr. Borger’s interpretation, you just have to believe in chemical processes we understand – processes that contribute to genomic decay.
I hope you are beginning to see why I think Dr. Borger’s work is so important. It may very well be as important to our understanding of genetics as Signature in the Cell has been to our understanding of the origin of life.
2. Kutchera, U. and Niklas K.J., “Photosynthesis research on Yellowtops: Macroevolution in progress,” Theory in Biosciences 125: 81-92, 2007
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