Sandwalk: Ann Gauger moves the goalposts: «We've been discussing Ann Gauger's claim that evolution is impossible because she was unable to transform a modern enzyme into another related one by changing a small number of amino acids.
I pointed out that this is not how evolution works. In some cases, you can easily show that two enzymes with different specificities can evolve from a common ancestor that could carry out both reactions.
Turns out that changing one related enzyme into another with a different specificity wasn't the goal of her experiment. Here's what she was really trying to do ...
The Big Problem
Here's the big problem -- the arrival of novelty.
Novelty or innovation means the appearance of something not already present. It's the opposite of promiscuity. So a way to create novelty is absolutely essential to explain modern cells, as I will demonstrate.
Here's the heart of the matter. Promiscuity cannot solve the problem of novelty. Mutation, natural selection, and drift cannot drive the creation of novelty of all those new protein folds. That's what Doug Axe and I have been testing all along, from Doug Axe's 2004 paper to this most recent one. Based on our experiments, the problem of how innovation originates remains unsolved.»
O meu comentário: "...provided the capacity for the reaction already exists in the starting enzyme..." - Acho que é com essa parte (e não com o que vem a seguir) é que a Gauger se "preocupa" - pelo menos agora. Mas funcionalidade imperfeita/ baixa pode aparecer "por acaso" (sem selecção) (1). E como Paul McBride disse:
«Gauger: "Based on our experiments, the problem of how innovation originates remains unsolved."
"They (Gauger and Axe 2011) have confirmed that evolution isn't a conscious process that picks specific proteins and makes them evolve into specific other proteins.» Gauger e Axe não testaram nenhuma hipótese evolutiva nem nada parecido com evolução.