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Author Topic:   Another IDology challenge -- complete with complaints of harsh treatments ...
Posts: 10197
Joined: 03-06-2009
Member Rating: 3.1

Message 49 of 63 (861998)
08-30-2019 12:59 PM
Reply to: Message 45 by WookieeB
08-29-2019 1:36 PM

Re: more filling in the blanks.
WookieeB writes:
How are you justifying that the 10^77 number is fabricated? Cause you don't like it?
It is fabricated because it hasn't been empirically tested. It is a fabrication of the assumptions Axe makes.
However, we can test Axe's calculations empirically. VDJ recombination during B-cell development produces billions B-cell lineages each with their own antibodies. The variable region of these antibodies can serve as a model for finding function. In fact, we can see if any of those antibodies have B-lactamase activity, the function that Axe says can only occur once in every 1x10^77 combinations.
Here we report the construction of a large murine single chain fragment variable (scFv) phage display library of size 2.7 10^9 with extended diversity by combining different mouse models. We have used two molecularly different inhibitors of the RTEM lactamase as targets for selection of catalytic antibodies with lactamase activity. This novel methodology has led to the isolation of five antibody fragments, which are all capable of hydrolyzing the lactam ring.
Just a moment...
In a library of 2 x 10^9 random peptides they were able to find 5 of those random peptides that had B-lactamase activity, well below the number given by Axe. Even if we look past all of the problems with Axe's mathematical model, reality shows us that Axe is wrong by many orders of magnitude.

This message is a reply to:
 Message 45 by WookieeB, posted 08-29-2019 1:36 PM WookieeB has replied

Replies to this message:
 Message 56 by WookieeB, posted 09-19-2019 7:04 PM Taq has replied

Posts: 10197
Joined: 03-06-2009
Member Rating: 3.1

Message 60 of 63 (863125)
09-20-2019 1:20 PM
Reply to: Message 56 by WookieeB
09-19-2019 7:04 PM

Re: more filling in the blanks.
WookieeB writes:
No, the results were determined via empirical testing. Experiments were done.
The conclusions Axe drew from the results were faulty and fabricated. He assumed that his experiment would capture all possible B-lactamase proteins.
But that was not his claim. You are not properly understanding (or are just arguing a strawman) to what Axe was claiming. So your statement ends up being irrelevant.
If Axe's claim is not relevant to the chances of a functional B-lactamase emerging from random sequence, then his claim is irrelevant to evolution.
His claim was NOT saying that finding peptides that have B-lactamase activity is 1 in 10^77.
Then what is it?
Besides, in your statement, "random" is a bit misleading, because the experiment did not use wholly "random" peptides. They were constrained in the same protein family.
So you are saying that it is easy to evolve a B-lactamase enzyme by randomly changing a small portion of the same protein? If so, then what is your problem with evolution?

This message is a reply to:
 Message 56 by WookieeB, posted 09-19-2019 7:04 PM WookieeB has not replied

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