Do molecular biologists deal with evolution on a daily basis?

[(Q)]

I would say they do deal with evolution on a daily basis, in that not only do they study the interactions of cell systems, the must also question the origins in order to understand the mappings.

 

[S.A.M.]

I would say they do deal with evolution on a daily basis, in that not only do they study the interactions of cell systems, the must also question the origins in order to understand the mappings.

Oh, like how?

 

[iceaura]

I doubt that. There are plenty of futile cycles, for one thing.

Hmmm. Are you sure ? Because they would be rare, under Darwinian pressures. They would need explanation - something maintaining them.

The necessity of an explanation for such oddities is one of the contributions of Darwinian theory. If you don't know what is maintaining a futile cycle against evolutionary pressure, you are missing something. That perception of a gap in understanding is a major contribution of a good theory.

Meanwhile, I quote from your link:

The cycle does generate heat, and may be used to maintain homeostasis

It discourages. (I am also in something of a semantic quagmire to understand how, without stretching meaning, an operational feature can be useless.)

I refer you to SAM's link, also the misunderstood version of the appendix, which was accepted as an organ that "operated" - did things, had an effect - but nothing useful.

Darwinian Theory forbids the simple acceptance of such a view - the appendix is obviously expensive, and therefore either useful or in some way positively maintained from an ancestral state of usefulness. It requires explanation, and the lack of an explanation points to a gap in our knowledge and a field of inquiry.

 

[S.A.M.]

Hmmm. Are you sure ? Because they would be rare, under Darwinian pressures. They would need explanation - something maintaining them.

Not necessarily, if it doesn't kill you, it will not be eliminated. How could it?

 

[Ophiolite]

iceaura, I don't know what you mean by Darwinian theory. I know what a creationist means by it and I know you are not a creationist. You seem to be using the term in a peculiar way. Perhaps you can elaborate. Are we talking Darwinian senuso stricto, Modern Synthesis, MS + some evo-devo? Or something else? It does make a difference you know.

A 'useless' feature that is determined by genes will tend to remain in place until removed by a mutation, or 'overwriting' by another gene. If these do not occur the feature will be there.

 

[iceaura]

Not necessarily, if it doesn't kill you, it will not be eliminated. How could it?

By reducing the resources available for successful reproduction, directly or indirectly.

Something will kill you. It will more likely kill off the rarer of of you.

A 'useless' feature that is determined by genes will tend to remain in place until removed by a mutation, or 'overwriting' by another gene.

And mutations happen all the time. Any that knock out a "useless" expensive feature will improve the bearer's chances of successful reproduction.

It's odds and time, in a situation of culling.

 

[Ophiolite]

Which still make 'discourage' a more accurate term, in my view. If you differ - fine.

 

[S.A.M.]

By reducing the resources available for successful reproduction, directly or indirectly.

How would the resources be reduced for a useless cycle if it does not decrease viability? They may be potentially beneficial. Fat people may in todays climate benefit from futile cycles that waste energy.

 

[w1z4rd]

now this guy is responding:

Junk DNA was thought of as evolutionary leftovers, even though it takes a lot of cellular energy (and thus a cost to fitness) to copy. The theory of evolution did not help a thing in discovering the various functions of junk DNA. And then there are examples of evolutionary conserved sequences that have no effect on fitness. The theory of evolution had nothing to do with increasing our understanding of these sequences. Once again, it is just basic operational sciences at work. Good old PCRs, genetics and bioinformatics.

and

in response to the algorithms comment:

As to evolutionary algorithms, they were created by scientists/programmers. So no, they did not magically appear out of thin air. Did they use the theory of evolution to make it? Read up a bit about Lamarckian genetic algorithms

 

[iceaura]

How would the resources be reduced for a useless cycle if it does not decrease viability?

What is spent in (truly, genuinely useless) futile cycles is not available for reproduction.

That reduces the reproductive capability of the organism.

That would almost certainly be selected against, in Darwinian evolutionary theory. So the theory focuses the attention of the researcher on a likely field of inquiry - namely, an accounting of that futile cycle. Its existence needs explanation.

 

[Cyperium]

Evolution is a myth. Just look at Ophiolite.

lol the worst part is that you have a point!

But it might just be social evolution. That's appearently what the people wants!

Perhaps democracy has weak spots...

 

[ElectricFetus]

Junk DNA does a very valuable function: it allows the chromosomes to line up during crossing over during meiosis, "junk" DNA accumulated in eukaryote because to loss it meant no longer being able to reproduce sexually. This is why a better term for it is structural DNA. This is why eukaryotes have so much structural DNA while prokaryotes have very efficient genomes with little non-transcribed DNA because prokaryotes do not reproduce in a truly sexual manner.

 

[Hercules Rockefeller]

...."junk" DNA accumulated in eukaryote because to loss it meant no longer being able to reproduce sexually.

Not necessarily so.

For instance, there have been some amazing experiments where people have engineered mice with huge deletions in non-coding DNA with no apparent resulting phenotype. One example is linked below – they deleted 1.5 megabases of non-coding DNA and homozygous mice carrying the deletion were normal with normal fertility.

“…these studies further support the existence of potentially 'disposable DNA' in the genomes of mammals”, says the abstract.

http://www.nature.com/nature/journal/v431/n7011/abs/nature03022.html

 

[ElectricFetus]

Not necessarily so.

For instance, there have been some amazing experiments where people have engineered mice with huge deletions in non-coding DNA with no apparent resulting phenotype. One example is linked below – they deleted 1.5 megabases of non-coding DNA and homozygous mice carrying the deletion were normal with normal fertility.

“…these studies further support the existence of potentially 'disposable DNA' in the genomes of mammals”, says the abstract.

http://www.nature.com/nature/journal/v431/n7011/abs/nature03022.html

Oh well I guess my theory is out the window than.