Evolution Pros and Cons

[HydrogenBond]

There is a misunderstanding, that there are only two possible positions when it comes to evolution. Either you are for it or you are a creationist. The position I take is evolution is essentially genetic based, leading to selective advantage. But there is also a middle area that is a little thin.

I am trying to point out if we start with a genetic change, there is an entire middle that has to happen before we reach selective advantage. For example, say we have a new gene forming on the DNA that has the potential to do a new task. This is new and neither the cell or the DNA have any history with it. Somehow it has to fit in, not only in terms of placement, but it also might need logistical support from transport proteins that may not even exist. The middle aspect of evolution is how we go from the genetic change to selective advantage.

The analogy is the genetics is the CEO of a corporation. He has is a new idea. The genetic ideas goes down the chain of command. Evolution skips from the CEO to plotting sales. This is all true but it does not tell about all the proteins in the trenches who make it all happen.

[Biochemist]

Originally Posted by HydrogenBond

There is a misunderstanding, that there are only two possible positions when it comes to evolution. Either you are for it or you are a creationist.

Hmmm. Given that there is a reasonably wide breadth of opinion on lots of evolutionary elements and that there are at least a dozen different views that accept the intervention of God, this strikes me as a little narrow. I have several (maybe even lots) of Christian friends that think evolution occurred by the generally accepted mutative model. What are they? Probably a lot of them think it couldn't have happened without divine intervention becasue the odds are so terrible. In fact, I used to be one of those (before I began to reject mutation-driven speciation). What position is that??

[Moontanman]

Originally Posted by Biochemist

Hmmm. Given that there is a reasonably wide breadth of opinion on lots of evolutionary elements and that there are at least a dozen different views that accept the intervention of God, this strikes me as a little narrow. I have several (maybe even lots) of Christian friends that think evolution occurred by the generally accepted mutative model. What are they? Probably a lot of them think it couldn't have happened without divine intervention becasue the odds are so terrible. In fact, I used to be one of those (before I began to reject mutation-driven speciation). What position is that??

I am very curious, I have followed this thread for a while but don't pretend to understand exactly what is being said from your end so please explain to me exactly what does drive speciation? Don't bother with the details, where does the change come from?

[Essay]

Originally Posted by HydrogenBond

Evolution skips from the CEO to plotting sales. This is all true but it does not tell about all the proteins in the trenches who make it all happen.

I'm no expert (but I did study at a Holiday Inn ), but I think evolution theory incorporates all of that middle ground of proteins, regulation, timing, etc.
Notice that this leads to a lot more complexity and potential for variation than the normal view of CEO jumping straight to sales.
===

Your characterization of the process by which a gene finds its proper expression, "This [gene] is new and neither the cell or the DNA have any history with it. Somehow it has to fit in, not only in terms of placement, but it also might need logistical support from transport proteins that may not even exist," reveals a normal misunderstanding of evolution; but there is no unknown "middle ground."

Today's transport (& regulatory) proteins may not have existed when the gene mutated, but something was there that made that mutation workable (or neutral), and in some helpful way eventually. It may have been competely unrelated to the previous function of the gene, or it may have improved on the previous function--under certain conditions.
What a gene expresses (& how much + when) doesn't need any more direction as to how or where to "fit in" than do the genes themselves. A random collection of gene products will undergo natural selection, just as will a random collection of gene mutations (or outward, phenotypic expressions).

If a particular new gene (mutant) product will only become functional by co-opting or highjacking some intermediate from a different metabolic pathway, you wouldn't say that the gene must have" known" that the particular intermediate would be available, would you?

[Biochemist]

Originally Posted by Moontanman

I am very curious, I have followed this thread for a while but don't pretend to understand exactly what is being said from your end so please explain to me exactly what does drive speciation? Don't bother with the details, where does the change come from?

I think the data better supports that DNA pre-codes for DNA changes. I suggest that speciation is not because mutations alter DNA serially, and then express, and then are selected. It is because the parent species has a propensity to alter itself into the daughter species. This essentially puts all of the code for the common ancestry into the first life form. A little tough to accept, but I think this is the most consistent with the extant data. It does (certainly) make the abiogenesis process that nuch more difficult, but it is what it is.

I ran a whole thread on this topic a couple years. The title was something like "statistical/probabilisitic issues with speciation".

[Moontanman]

Originally Posted by Biochemist

I think the data better supports that DNA pre-codes for DNA changes. I suggest that speciation is not because mutations alter DNA serially, and then express, and then are selected. It is because the parent species has a propensity to alter itself into the daughter species. This essentially puts all of the code for the common ancestry into the first life form. A little tough to accept, but I think this is the most consistent with the extant data. It does (certainly) make the abiogenesis process that nuch more difficult, but it is what it is.

I ran a whole thread on this topic a couple years. The title was something like "statistical/probabilisitic issues with speciation".

Ok, where does this precode come from? I am completely comfortable with current theory of abiogenesis and it certainly does not allow for the presetting of genes for modern species in the original genome so where would your preset genes come from?

[Pyrotex]

Originally Posted by HydrogenBond

...For example, say we have a new gene forming on the DNA that has the potential to do a new task. This is new and neither the cell or the DNA have any history with it. ....

It would sure make these conversations easier if you would find a simple book on evolution and genetics and just read it.

Anyway, genes are NOT associated with "tasks" or "processes" or "functions" or even bodily structures. Genes are associated with chemistry. Typically, a gene is associated with specifying an amino acid in a protein or enzyme. When the DNA is scanned within the cell, this process builds a protein or enzyme.

So, if a new gene is inserted into DNA, you do NOT get a "task" or "order" that can't be passed down from CEO to mailroom clerk. What you DO get is a protein with an extra amino acid in it. This will cause the protein to bend and twist into a different shape. Maybe very different, maybe only subtly different. The presence of this new protein may kill the host animal or may do nothing or may change its, say, eye color.

[CraigD]

Originally Posted by Pyrotex

Anyway, genes are NOT associated with "tasks" or "processes" or "functions" or even bodily structures. Genes are associated with chemistry. Typically, a gene is associated with specifying an amino acid in a protein or enzyme. When the DNA is scanned within the cell, this process builds a protein or enzyme.

I agree with Pyro’s general statement that individual genes “are associated with chemistry”, not much more complex biological functions. However, that a gene specifies a single amino acid is incorrect.

The DNA/RNA structure that codes for a single amino acid is the codon, and consists of exactly 3 base pairs. There are exactly 64 codons, some of which code for the same amino acid, and 3 codons that don’t code for an amino acid, but rather signal the transcription “factory” involved in expressing proteins to stop.

By modern microbiological definition, a gene specifies an entire protein, which may consist of hundreds of amino acid subunits. In addition to the coding region of a gene – its exons – eukaryotic genes contain non-coding segments – introns – and other regions that don’t encode proteins, but rather aid transcription factors in locating the gene, and are generally considered part of the gene.

[Pyrotex]

Originally Posted by CraigD

I agree with Pyro’s general statement that individual genes “are associated with chemistry”, not much more complex biological functions. However, that a gene specifies a single amino acid is incorrect....

I stand corrected. Thanks!!!