Evolution: how do new proteins develop for use (Evolution)

by David Turell , Friday, March 12, 2021, 23:04 (1140 days ago) @ David Turell

Proteins in life are large and complex in form in order to deliver the proper necessary fuctions:

https://phys.org/news/2021-03-proteins.html

"That completely new proteins—and, with them, new properties—can emerge practically out of nothing, was inconceivable for decades, in line with what the Greek philosopher Parmenides said: "Nothing can emerge from nothing" (ex nihilo nihil fit). Working with colleagues from the U.S. and Australia, researchers from the University of Münster (Germany) have now reconstructed how evolution forms the structure and function of a newly emerged protein in flies.

***

"It had been assumed up to now that new proteins emerge from already existing proteins—by a duplication of the underlying genes and by a series of small mutations in one or both gene copies. In the past ten years, however, a new understanding of protein evolution has come about: proteins can also develop from so-called non-coding DNA (deoxyribonucleic acid)—in other words, from that part of the genetic material which does not normally produce proteins—and can subsequently develop into functional cell components. This is surprising for several reasons: for many years, it had been assumed that, in order to be functional, proteins had to take on a highly developed geometrical form (a 3D structure). It had further been assumed that such a form could not develop from a gene emerging at random, but would require a complex combination of amino-acids enabling this protein to exist in its functional form.

"Despite decades of trying, researchers worldwide have not yet succeeded in constructing proteins with the desired 3D structures and functions, which means that the "code" for the formation of a functioning protein is essentially unknown...Despite decades of trying, researchers worldwide have not yet succeeded in constructing proteins with the desired 3D structures and functions, which means that the "code" for the formation of a functioning protein is essentially unknown... proteins are constantly being formed de novo (anew)—i.e. without any related precursor protein going through a selection process.

"The vast majority of these de novo proteins are useless, or even slightly deleterious, as they can interfere with existing proteins in the cell. Such new proteins are quickly lost again after several generations, as organisms carrying the new gene encoding the protein have impaired survival or reproduction. However, a select few de novo proteins prove to have beneficial functions. These proteins integrate into the molecular components of cells and eventually, after millions of years of minor modifications, become indispensable.

***

"The results match up with several other current studies, which have shown that the genomic elements from which protein-coding genes emerge are activated frequently—tens of thousands of times in each individual. These fragments are then sorted through the process of evolutionary selection. The ones which are useless or harmful—the vast majority—are quickly discarded. But those which are neutral, or are slightly beneficial, can be optimized over millions of years and changed into something useful."

Comment: Fascinating, because it is a Darwinian attempt to explain how useful proteins appear by chance. They assume it takes many chance attempts over millions of years. They used computer simulations based on Darwin theories. What it doesn't explain is how the requirement for two simultaneously necessary proteins would appear together. I'm still with God as the designer