pangloss

If there is an insertion of a transposable element within an established gene, would the result be:


1. loss of information
2. gain of information
3. no change in information content
4. irrelevant as to the information content of that particular gene


and would this change affect the overall fitness of the organism?

Would it affect the information content of the genome as a whole?

GeoTheo

That all depends. There is no one right answer.
Too many variables. The question is not as simple as you migt think. It could do all kinds of things, including nothing.

GeoTheo

What do you mean by "established gene"? Do you men necessary gene? A gene in which all mutations are always fatal? How many copies of this gene are there in the genome? Some mutations can change the molecular structure of a protein, but have no visible effect in the organism.
This could be a "loss of function mutation" or a "gain of function" mutation. If it is a loss of function mutation it would be recessive and might perhaps not have a visible affect.
Somtimes a later deletion will take out the insertion in whole or part. Does this mutation cause a frameshift? Was it in an intron region or an extron?

pangloss

By established I mean already present. is there such a gene? Irrelevant. Indeed, but also irrelevant to the information issue. Why would it be recessive? Either.

GeoTheo

I think a lot of the molecular genetics info in the Talkorigins website is kind of like "pop" molecular genetics. You seem to be following a talk Origins train of thought. I am finding that molecular genetics is a lot less cut and dry than is somtimes implied in creation/evolution debates.
Things that are only partially understood like transposons are presented as part of slam dunk arguements for evolution.
Transposons can do all kinds of things, they seem to have no other purpose but to make copies of themselves. Effects this can cause on the organism are:
1. no appreciable effect
2. disease
3. hrybrid dysgenesis which could lead to speciation
4. a change in a gene that may be selected by natural selection if it brings some type of adaptive advantage.
As far is "information content" I'm not sure what you mean. Transposons create repetitive sequences so I would say their information content is pretty low. The part of the genome that actually codes for things is composed of unique sequences. Natural selection seems to have put some things in place that are kind of like safe guards preventing transposons from screwing things up to bad for the host organism.
As far as your question about necessary and unnecessary genes. Yes there are such genes. You Can find them by causing a mutation in them and then obseving the effect on the organism. This was done extensively with drosiphilia. Fatal mutations cause death. Non fatal mutations that cause a loss of function are recessive. That is what recessive genes are. Gain of function mutations are dominant.

[ October 04, 2002: Message edited by: GeoTheo ]</p>

pz

I think you need to read some more of that basic "pop molecular genetics" on <a href="http://talkorigins.org/" target="_blank">talkorigins.org</a>, since you've got some very simple stuff completely wrong. No, that is not what recessive genes are; recessive alleles can cause lethality when homozygous. Recessive alleles have no detectable phenotype when heterozygous.

Transposons do carry unique sequence information. They typically carry transposition genes and miscellaneous other genes along for the ride.

S2Focus

You have stumbled upon the very heart of the problem here. Nobody (including ID advocates) knows just what "information content" means as it relates to "intelligent design theory".

This "information content" term that ID proponents like to toss around is really quite a mysterious quantity. Nobody can define it, and nobody knows how to measure or compute it. But lots of folks "know" that that it poses a serious challenge to evolutionary theory.

davidH

hmmm, yeah I'm starting to study this here.

You know to me it seems as if the DNA code is getting progressively "eaten away at" by mutations.
I know evolution relies on mutation giving more information, but is that what is happening at this present moment in time?
There are now thousands of genetic disorders/diseases due to mutations and yet relatively few (if any) mutations that are benefical.

Would it not be logical to assume that once the population reaches the maximum that the environment can support, that these harmful mutations will eventually wipe humanity off the earth?
Let me explain myself.

Harmful mutations are removed by natural selection. At the moment these are far more abundant than any benefical mutations of humans - if indeed there are any that have occurred. So all organisms with harmful mutations are removed (all those genetic diseases that now abound).
If for every 100 harmful mutations there is one benefical mutation, then the odds of the carriers of the benefical mutation surviving the harmful mutations are low. For the benefical mutations won't make us immune to the thousands of harmful mutations that abound.

That being the case wouldn't we genetically go down hill - even the slight peaks of any benefical mutations that happened to occur wouldn't make a difference to the downward trend?

That's how I tend to see it happening anyway. With industry increasing the rate of harmful mutations seems to increase and as industry is set to keep on growing this mutations will still occur. Everything seems to point to human's genetic code getting progressively worse with genetic diseases abounding...

Any thoughts on this? What does the medical trend show - an increase in the amount of genetic conditions over the last decades?

It would be interesting to see this researched.

GeoTheo

I no doubt do have some things wrong as I am only eight chapters into Benjamin Lewin's "GENES IV" and am a second year biology student.. I still think a lot of people on forums like this like to trot around stuff about molecular genetics that is not fully understood. The question posed at the start of this thread is extremely broad IMO.
I see now that they must have been the intent of Pangloss. Since ID advocates like to talk about information theory and relate it to genetics.

Wyz_sub10

GeoTheo,

You accept evolution, don't you? I thought you have said you did. If so, I think pangloss was looking for a creationist response to this. If you accept evolution, you'll probably have no problem with evolution adding information (which has been a cornerstone issue for creationism).