A problem with molecular evolution?

im of course refer to your objection to my calculation.

there is if only one in 10^9 mutations is functional.

do you have an example of a specific hormone that function with and without its receptor?

the same question above.

i dont think its the case, since im talking about any function, and not just about a specific one.

indeed. this is why i asked for your estimation.

how exactly? the article is talking about many ways to get a specific function from the same starting point. but it doesnt tell us much about the chance to get a new function.

i think we can get some idea about that number. for instance: do you agree with me that the assumption that one in about million births we can get a new function (and i mean any new function) such as a venom, or a venom sac or a stinger?


(image from Bee stings and stinger removal: have we been doing it right?)

i think this is very generous estimation since we never seen such a thing evolving, even though we watched billions of insects (in or out of the lab). do you agree with that?

im talking about two genes\anatomical parts which depend on each other. so they are neutral in themselves.

if the snake start to produce venom, isnt that a problematic situation without a self resistance?

The phrase “may ways” is the give away. You might also want to clarify in your mind the difference between a “specific function” that did not exist before, and a “new function.”

What I was saying is that a hormone doesn’t require a brand new receptor. A modified hormone can bind to an already existing protein.

Would you agree that these features would more than likely be modifications of systems that already exist, and that venom could be beneficial without a specialized venom sac?

Again, you are ignoring exaption.

You are already shifting the goalposts.

To me, it’s a mathematical model that can be used to make predictions by using appropriate equations and parameters.

To you, it’s a magic phantasm that bolsters your opinions.

Let’s take a look at a paper which directly addresses the hormone-receptor question in the opening post.

Here is the problem. Most vertebrates have two hormone receptors that originated from a gene duplication deep in the vertebrate tree:

mineralocorticoid receptor (MR) : binds to both cortisol and aldosterone, but is associated with aldosterone because it resides in tissue that quickly clears cortisol.

glucocorticoid receptor (GR) : binds to cortisol

So the question is how could aldosterone evolve without a receptor to bind it? Without aldosterone, why would a receptor evolve to bind it?

To answer this question, Bridgham et al. (2006) reconstructed the ancestral protein from before the gene duplication. They could do this because the agnathan branch split off before the gene duplication.

So what did they find when they expressed the reconstructed ancestral gene? It was able to bind aldosterone, even though aldosterone had not evolved yet.

So just as I said, a new hormone can bind to an already existing hormone receptor that had evolved to bind other hormones. As the paper states:

1 Like

Didn’t we JUST GET DONE hashing this one out with Kleinman already?

I don’t think universal common descent is a reasonable inference at this point. How much ancestral connection there is between species is open up for debate. The discussion of primate ancestry is certainly up for debate as is rodent common ancestry etc.

Subtlety is lost on you, apparently. Are you familiar with the acronym “GIGO”? That describes your “calculation”.

How would you debate it?

1 Like

Getting people to think scientifically is worthwhile.

@colewd, if you were a scientist, which all humans generally are to some extent (even babies when they try to eat everything or grab everything are scientists in a sense), how would you go about proving (or providing evidence for) or disproving (or providing evidence against) human-primate, human-rodent common ancestry?

Are there any testable hypotheses you might try and test?

1 Like

Getting Bill to think scientifically is more quixotic than worthwhile. But good luck to you. They might be giants.

2 Likes

Since you are not interested in reading the sources offered to you, I see no basis on which we can have a productive conversation.

Best,
Chris

2 Likes

Is this the paper you are talking about?

De novo gene birth is the process by which new genes evolve from DNA sequences that were ancestrally non-genic. De novo genes represent a subset of novel genes, and may be protein-coding or instead act as RNA genes [[1](https://journals.plos.org/plosgenetics/article?
id=10.1371%2Fjournal.pgen.1008160#pgen.1008160.ref001)]. The processes that govern de novo gene birth ( Fig 1A ) are not well understood, though several models exist that describe possible mechanisms by which de novo gene birth may occur.

Surely you can see why this statement is problematic, right? You just provided a quote that mentions multiple viable models that are further discussed in the paper.

2 Likes

Flat Earthers don’t think a Globe Earth is a reasonable inference at this point. Why should we care about your opinion any more than we care about the opinions of Flat Earthers?

1 Like

That is the paper.

1 Like

Hi Curtis
I can see this thanks. When I say “viable model” I mean one that is predictive and is demonstrated by testing its repeatability. The word model itself can have several meanings as the word evolution does.

How familiar are you with the LTEE literature?

1 Like

The mutation and selection model is tested every time there is an attempt to measure a phylogenetic signal in both the morphological and molecular data. The model repeatedly passes that test.

1 Like

I’m not clear on what that means. Might you explain?