This is from Evolution News.
Excerpt:
I am pleased to announce the publication of a new paper from Biologic Institute, a research organization devoted to investigating the limits of unguided evolution and advancing the development of a new paradigm for biology based on intelligent design. This paper, “Enzyme Families — Shared Evolutionary History or Shared Design? A Study of the GABA-Aminotransferase Family,” is the closing chapter of our long-term study of bacterial enzymes to determine if they can be coopted to new functions. The answer to this question is important for the evolution debate. If enzymes can’t be recruited to genuinely new functions by unguided means, no matter how similar they are, the evolutionary story is false.
Published in the journal BIO-Complexity, the work was done by Marci Reeves, Doug Axe, and myself [Ann Gauger].
In a previous paper we described the difficulty of coopting the enzyme Kbl to perform the function of BioF. The two enzymes are very similar in structure (see below) but have different reaction chemistries and different functions in the cell. We wanted to know if a mutated Kbl could replace missing BioF function. After changing nearly every amino acid in Kbl’s active site (where its chemistry is carried out) to look like BioF, Kbl never was able to make the switch to BioF’s function.
In this paper we expanded the story to include nine of the most closely related enzymes to BioF, including one that is supposed to be able to carry out both BioF’s and Kbl’s chemistry. Using random mutagenesis we tested every single-base mutation in those nine genes. None of them was within one mutation of cooption. We went on to test for cooption the two most likely enzymes by generating two-base combinations of mutations. After testing 70 percent of all possible two-base mutations for each enzyme, or about 40 million cells each, that also failed.
What does this mean? In an evolutionary scenario, to get an enzyme to switch functions the first step is to make a spare copy that can be mutated without destroying a function the cell needs. Second, the cell has to overproduce the mutating enzyme, because any newly emerging enzyme will be very bad at the job at first. To compensate there will need to be lots of enzyme around. Third, there is the problem of finding the right combination of mutations by random search.
Taken together, since we found no enzyme that was within one mutation of cooption, the total number of mutations needed is at least four: one for duplication, one for over-production, and two or more single base changes. The waiting time required to achieve four mutations is 1015 years. That’s longer than the age of the universe. The real waiting time is likely to be much greater, since the two most likely candidate enzymes failed to be coopted by double mutations.
Read the rest of the post, they deal with criticisms to the paper.
Here is one Darwinist’s view of this enzyme proble, which they mention in a follow-up post.
Look: (links removed)
Monday we published a paper in the journal BIO-Complexity demonstrating that enzymes can’t evolve genuinely new functions by unguided means. We argue that design by a very sophisticated intelligent agent is the best explanation for their origin. I want to take some time to lay out our argument against Darwinian evolution and for intelligent design. It’s important, because it reveals the logical fallacy in most evolutionary thinking.
Just to give an example of the thinking of ID critics, here is a passage from one of the references in our paper (Kherhonsky et al. (2006) Enzyme promiscuity: Evolutionary and mechanistic aspects.Current Opinion in Chemical Biology 10:498-508):
An oft-forgotten essence of Darwinian processes is that they occur gradually, while maintaining organism fitness throughout. Consequently, a reasonable assumption is that, ever since the emergence of the primordial living forms, very little novelty has evolved at the molecular level. Rather, existing genes were modified, or tinkered with’, to generate new protein structures and functions that are related to those of their ancestors. Unlike ‘out of the blue’ scenarios advocated by the ‘intelligent design’ school, ‘tinkering’ scenarios depend on the availability of evolutionary starting points. The hypothesis that the broad specificity, or promiscuous functions, of existing enzymes provide these starting points was first formalized by Jensen in a review that has inspired many. Jensen proposed that, in contrast to modern enzymes, primitive enzymes possessed very broad specificities. This catalytic versatility enabled fewer enzymes to perform the multitude of functions that was necessary to maintain ancestral organisms. Duplication of genes and divergence led to specialized genes and increased metabolic efficiency. Since Jensen, the structures of >30,000 proteins, and the sequences of hundreds of thousands, have taught us that these processes led to the creation of enzyme families and superfamilies. The vestiges of these divergence processes are the scaffold and active site architecture shared by all family members [6].
To summarize, the key points of that evolutionary argument are:
- Evolution is true. That is, enzymes have evolved new functions by a process of random mutation and natural selection.
- Modern enzymes can’t evolve genuinely new functions by random mutation and natural selection but can only tinker with existing functions.
- Therefore, ancient enzymes must have been different, capable of carrying out a broad range of enzyme activities.
- Those enzymes underwent duplication and diverged from one another, becoming specialized.
- How do we know this happened? Because we now see a broad array of specialized enzymes. Evolution is the explanation.
This begs the question of whether evolution is true. It is a circular argument unsubstantiated by the evidence and unfalsifiable. No one can know what ancient enzymes actually looked like, and whether they really had such broad catalytic specificities.
That’s insufferable badness.
It’s not enough for Darwinists to take the age of the universe and then assert that anything can happen in that time. The time from the cooling of the Earth to the appearance of first life is on the order of millions of years. There just isn’t time to generate these organic components by chance.
WINTERY KNIGHT 