Questions of Natural selection

[Confused]

At the end of Why Darwin Matters: A case against intelligent design, the author, Shermer, raises some interesting issues with Natural Selection. These will naturally be the issues for debate:

1) If natural selection is the primary mechanism of evolution, what is the role of chance and contingency in the history of life?

2) What is the target of Natural Selection: the individual organism; or the lower levels of genes, chromosomes, organelles, and cells; or the higher level of groups, species, etc.. Why?

[WelshBoy]

Sorry to simply correct something and not add to the debate but:

ST88:

And not to be picky (or tacky) but viruses have RNA, not DNA

There are viruses that use DNA as well as ones that use RNA.

http://en.wikipedia.org/wiki/Viruses

[Cephus]

But surely they would be entitled to say that God might exist, and might have a plan etc. Where the rational intellectual debate ought to be focused in my opinion is upon why any unsupported, dogmatic, assertion should be the basis for political action that inflicts needless harm on people.

They're as entitled to say that as I would be to say that the Flying Spaghetti Monster might exist and might have a plan. You don't make public policy based on what might exist, only on what demonstrably does.

Until Christians can do more than say that God might exist, I'm really not interested in accepting them as his spokesmen.

[ST88]

Sorry to simply correct something and not add to the debate but:

ST88:

And not to be picky (or tacky) but viruses have RNA, not DNA

There are viruses that use DNA as well as ones that use RNA.

http://en.wikipedia.org/wiki/Viruses

I have been working for a company that makes blood testing products, so you'd think I would have been able to remember this. Thank you for your correction.

[ST88]

ST88:

And not to be picky (or tacky) but viruses have RNA, not DNA

.

At what junction did I say that viruses have DNA? I simply put forth how viruses can use DNA.

I have been set straight with this comment, so please ignore it.

But irrespective of the appendix, the larger point is that it is still mutation that will get rid of it. Just because we don't need it doesn't mean it will go away. There has to be some kind of valid reproductive advantage to not having it.

Perhaps I am getting a bit confused here. Are you saying that mutations that occur that "phase something out" have to have some kind of valid reproductive advantage to not having it? There is no randomness to it? Perhaps I have been on rotation to long and need a bit more sleep. I think between you and QED, the past 24 hour rotation has sucked.

The randomness is in the mutation. I.e., there could have already been a mutation in one specific individual so that they do not have an appendix, but in order for this to become a trait endemic to the human species, this individual would have to a) have some kind of selective advantage over everyone else who has an appendix, and b) reproduce like mad. Since the appendix is largely irrelevant for reproductive survival, its existence is not mediated by natural selection (currently).

There may very well be a time when it will be an advantage not to have an appendix. Imagine if you will, a virus called B27Hu. This virus could be spread via airborne inhalation and lodges itself in the human appendix, where it sits for a few weeks, then attacks and causes it to rupture, thereby killing the host. Within a few of months of traveling on airplanes, cars, and ships, there are a whole lot of dead people. Those that survive would be those who (a) already had their appendix out, b) were born with a genetic abnormality whereby they did not have an appendix, or c) had special immunity for chemical reasons.

Thos who have had their appendix out would have a roughly 0% chance of having children who would be able to survive the virus. Those with the chemical immunity would have, say, a 5% chance of having children who could survive the virus. And those with the genetic abnormality would be likely to have, say, a 50% chance of having children with the same abnormality. This is my scenario, so these are my numbers. Those children who have the genetic abnormality would in turn be more likely to spread it to their offspring and so on until such time as the population becomes stable and growing. This is one way having an appendix might have selective advantage.

So the randomness is in the mutation, and the selectiveness is based on the environment. Selection, in this case, is only as random as the environmental factors that cause it to be a survival strategy. The incidence of virus B27Hu is the random event and the appendix mutation is sort of a co-random incidence, something that may have been happening all along (in .000001% of the population, e.g.) but is only exposed as an advantage upon encountering the virus.

[Greatest I Am]

At the end of Why Darwin Matters: A case against intelligent design, the author, Shermer, raises some interesting issues with Natural Selection. These will naturally be the issues for debate:

1) If natural selection is the primary mechanism of evolution, what is the role of chance and contingency in the history of life?

2) What is the target of Natural Selection: the individual organism; or the lower levels of genes, chromosomes, organelles, and cells; or the higher level of groups, species, etc.. Why?

The target will be whatever is required for survival.
Possibly the next step we see in our evolution will have to do with the lungs, thanks to all the chemistry we place into the air. Watch for it int he next 2-3 generations.

Regards
DL

[McCulloch]

Possibly the next step we see in our evolution will have to do with the lungs, thanks to all the chemistry we place into the air. Watch for it in the next 2-3 generations.

Maybe I was asleep during science class and missed the discussion about rapid evolution. Or maybe scientists have come up with something since then (it has been a few decades). Are there scientists who support the idea that there will be noticeable evolutionary developments in complex organisms such as mammals in a mere 2-3 generations?

[Greatest I Am]

Possibly the next step we see in our evolution will have to do with the lungs, thanks to all the chemistry we place into the air. Watch for it in the next 2-3 generations.

Maybe I was asleep during science class and missed the discussion about rapid evolution. Or maybe scientists have come up with something since then (it has been a few decades). Are there scientists who support the idea that there will be noticeable evolutionary developments in complex organisms such as mammals in a mere 2-3 generations?

I don't know your sleeping pattern.

What I do know is that I have noticed that it only takes one incidence of change to start the process of change to a species. One animal with a longer nose. One animal with a longer tongue. One animal smaller than the rest. As long as the new type produces greater value for the species as a whole then it will take. Nowhere is it writen that multigenerational change is the only change.
Did Einstein not change us as a species?

Regards
DL

[Cathar1950]

Did Einstein not change us as a species?

No but he did affect some of our cultures. We were already our species.
Yet there are some that say we are still evolving or that changes have been made thouisands of years ago that are still playing out and developing. We don't know if it will work as chnages take much longer befor they are displayed in a species attributes.

here is a little artical that i foiund interesting.

http://www.msnbc.msn.com/id/17542627/site/newsweek/

Beyond Stones & Bones
THE EVOLUTION REVOLUTION
By Sharon Begley
Newsweek
• The New Science of Human Evolution
• Live Talk: Sharon Begley on the new science of evolution

Live Vote
Do you believe that the theory of evolution can coexist with religion? * 15725 responses

Yes
59%

No
36%

Not Sure
4.9%
Not a scientific survey. Click to learn more. Results may not total 100% due to rounding.

Of course I found a group that found it proof of Adam and Eve.

http://www.accuracyingenesis.com/adam.html

BIBLICAL RESEARCHBIBLICAL ARCHAEOLOGY

The Evidences for a Recent Dating for Adam,
about 14,000 to 15,000 years Before Present

[Confused]

ST88:

And not to be picky (or tacky) but viruses have RNA, not DNA

.

At what junction did I say that viruses have DNA? I simply put forth how viruses can use DNA.

I have been set straight with this comment, so please ignore it.

But irrespective of the appendix, the larger point is that it is still mutation that will get rid of it. Just because we don't need it doesn't mean it will go away. There has to be some kind of valid reproductive advantage to not having it.

Perhaps I am getting a bit confused here. Are you saying that mutations that occur that "phase something out" have to have some kind of valid reproductive advantage to not having it? There is no randomness to it? Perhaps I have been on rotation to long and need a bit more sleep. I think between you and QED, the past 24 hour rotation has sucked.

The randomness is in the mutation. I.e., there could have already been a mutation in one specific individual so that they do not have an appendix, but in order for this to become a trait endemic to the human species, this individual would have to a) have some kind of selective advantage over everyone else who has an appendix, and b) reproduce like mad. Since the appendix is largely irrelevant for reproductive survival, its existence is not mediated by natural selection (currently).

There may very well be a time when it will be an advantage not to have an appendix. Imagine if you will, a virus called B27Hu. This virus could be spread via airborne inhalation and lodges itself in the human appendix, where it sits for a few weeks, then attacks and causes it to rupture, thereby killing the host. Within a few of months of traveling on airplanes, cars, and ships, there are a whole lot of dead people. Those that survive would be those who (a) already had their appendix out, b) were born with a genetic abnormality whereby they did not have an appendix, or c) had special immunity for chemical reasons.

Thos who have had their appendix out would have a roughly 0% chance of having children who would be able to survive the virus. Those with the chemical immunity would have, say, a 5% chance of having children who could survive the virus. And those with the genetic abnormality would be likely to have, say, a 50% chance of having children with the same abnormality. This is my scenario, so these are my numbers. Those children who have the genetic abnormality would in turn be more likely to spread it to their offspring and so on until such time as the population becomes stable and growing. This is one way having an appendix might have selective advantage.

So the randomness is in the mutation, and the selectiveness is based on the environment. Selection, in this case, is only as random as the environmental factors that cause it to be a survival strategy. The incidence of virus B27Hu is the random event and the appendix mutation is sort of a co-random incidence, something that may have been happening all along (in .000001% of the population, e.g.) but is only exposed as an advantage upon encountering the virus.

Ok, I grasp what you are saying now. But in your scenario, you are presenting a case in which evolution preceded selection then, or am I misunderstanding your scenario. If the production of the appendix serves no purpose now, but may in the future, then are we not saying that evolution predicts selection to degree or that natural selection is by chance noting the subtle changes in the environment that perhaps we aren't cognizant of yet, and adapting the body slowly for the eventuality it percieves is coming? In such a case, it wouldn't be natural, or random, but rather it would be guided by the environment in which we live.

Perhaps I am not grasping what you are saying. Perhaps 20 hours of sleep didn't clear the confusion as I had hoped.

[Goat]

Ok, I grasp what you are saying now. But in your scenario, you are presenting a case in which evolution preceded selection then, or am I misunderstanding your scenario. If the production of the appendix serves no purpose now, but may in the future, then are we not saying that evolution predicts selection to degree or that natural selection is by chance noting the subtle changes in the environment that perhaps we aren't cognizant of yet, and adapting the body slowly for the eventuality it percieves is coming? In such a case, it wouldn't be natural, or random, but rather it would be guided by the environment in which we live.

Perhaps I am not grasping what you are saying. Perhaps 20 hours of sleep didn't clear the confusion as I had hoped.

Not quite. Variation preceeded selection, but it is the variation + selection process that is evolution. There also could be random variation that is neither selected for or against, until there is a change in the environment. The variations are also 'evoultion" (change of the frequency of allese over generatoins), but not nessesarily due to environmental selection.