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Common sensor in bacteria and humans highlights reason for doubt re Darwinian tales

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We are told that the common sensor could lead to improvements in drugs:

Scientists have discovered that a human receptor protein has the ability to detect individual amino acids in exactly the same way that bacteria do. The finding could lead to enhancements of drugs derived from the amino acid GABA.

The finding could lead to enhancements of drugs derived from the amino acid GABA, but also has evolutionary implications: It adds to the sparse evidence suggesting there are commonalities between bacteria and humans with respect to sensing the presence of essential components of life, such as oxygen and food.

Receptors on cell surfaces detect all kinds of nutrients — fats, sugars and vitamins, for example — but use different types of protein segments called sensors, and no common chemical detection mechanism is currently known.

In this work, scientists discovered a universal sensor present in many different receptors that detects amino acids by precisely interacting with the two groups of atoms that are shared by all amino acids.

“For the first time, we’ve found the universal way of detecting amino acids. Nearly every organism can do it through this mechanism,” said Igor Jouline, senior author of the study and a professor of microbiology at The Ohio State University.

“In our experience, it’s very rare when we can extrapolate a very specific sensory function with such precision from bacteria to humans, because these life forms are separated by such a long evolutionary time — about 3 billion years.”

Ohio State University, “The rare discovery of a protein function universal to bacteria and humans” at ScienceDaily (March 1, 2022)

The media release doesn’t bang on about common ancestry. It is suitably cautious: “Though there may never be a definitive answer to the age-old question of what exactly bacteria and humans have in common biologically, Jouline has begun a broader search for sensors that have a role in sustaining life.” In fact, the commonality is more likely due to horizontal gene transfer, as increasing numbers of instances are identified, especially between bacteria and other life forms.

But that raises an interesting point. Recently, I (O’Leary for News) asked an obvious question, “in a world where horizontal gene transfer is this extensive and significant, what becomes of all the carefully structured Darwinian tales of the gradual development of selective advantage? Aren’t they just evolutionary fiction, a form of historical fiction?”

Especially at Twitter (well, where else, for this type of thing?), Darwinians were quick to weigh in, claiming essentially that Darwinism can SO accommodate horizontal gene transfer!

Well, just a minute here. Horizontal gene transfer is much better demonstrated than Darwinism as a fact in nature. With HGT, we aren’t looking for long-sought “missing links,” for example. We don’t need to. We can read the genes. In short, Darwinism had better accommodate HGT.

Second, and one cannot expect a classical Darwinian to want to see this, HGT obviates Darwinian just-so stories according to which things happened by a long slow process of natural selection acting on random mutation. In such cases, we now know how they happened and it wasn’t according to Darwinian theory as classically set out.

What we don’t know is, how many other mutations in nature are better explained by HGT than Darwinism? We are only beginning to find out.

Here’s a simple illustration: Suppose Jane composes a song, both score and lyrics. She copyrights and performs it. Jane is the origin of the song.

Alternatively, Jane buys the sheet music, lyrics, and performance rights, and performs the song. That’s like horizontal gene transfer.

Suppose someone writes a long harangue in an arts journal about what inwardly motivated Jane to compose the song — and then discovers that she in fact bought it off the internet?

The long harangue in the journal is like the Darwinian just-so story. It assumes an origin that may not be true. And we don’t know in how many cases it is — vs. isn’t — true.

At this point, claims that Darwinism can “accommodate” HGT should be seen for what they are special pleading in the face of challenging new findings in evolution.

The paper is open access.


You may also wish to read:

You may also wish to read: Animal DNA modifier captured from bacteria 60 million years ago The obvious question this raises is, what about all the detailed Darwinian narratives that a horizontal gene transfer could obviate?

and

Researchers: Bacteria provided plants with genes to colonize land. Again, we ask, if so, in a world where horizontal gene transfer is this extensive and significant, what becomes of all the carefully structured Darwinian tales of the gradual development of selective advantage? Aren’t they just evolutionary fiction, a form of historical fiction?

Comments
A new viewpoint might see genes as just another form of food, absorbed in a different way. We crave proteins and carbohydrates and fats for different purposes, and we have specific sensors on the tongue to detect each type of nutrient. Do we have 'official sensors' for types of genes in food?polistra
March 5, 2022
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Suppose someone writes a long harangue in an arts journal about what inwardly motivated Jane to compose the song — and then discovers that she in fact bought it off the internet
Good analogy and great analysis throughout. Yes, exactly. Darwinism is supposed to tell use the origin of the features, but now they can accommodate an entirely different mechanism that requires structures to already be built but then just transferred. Of course, they'll say that RM and selection created the components and then HGT moved them around, but this all reveals that nobody can put any confidence in Darwinian claims. They should just admit that they don't know.Silver Asiatic
March 4, 2022
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