What’s your problem?

[Micaiah]

It doesn’t matter if it’s an eagle with poor sight or a slow impala. Any trait that gives an organism a disadvantage leads to less reproductive success in the long run. I think you understand that much at this point.

A mutation may spread through a population, whether it does or doesn't is only very slightly influenced by the survival advantage that the mutation may bestow.

The probability an animal such as an impala is the result of a number of small genetic mutations and natural selection can be and has been calculated. The chance of this happening is a function of the chance the mutation occurs in the first place, and then the chance the mutation survives and is passed onto the the population.

To support the claim that animals are the result of evolution, you need to be able to quantify statistically that this is feasible.

 

[Dannager]

The probability an animal such as an impala is the result of a number of small genetic mutations and natural selection can be and has been calculated.

For Pete's sake, quit moving the goalposts. We're not talking about the evolution of the first impalas yet! We're just talking about mutation and natural selection as they pertain to impala speed. We haven't finished with that yet. Now go back to my last post on impala speed and show me which numbers you don't like...or you could always offer a retraction.

 

[Jet Black]

come on Micaiah, keep going with the example of dannanger's that you were so critical of, and of course you might like to explain your use of the word "tacit" as well. we can all see you furiously trying to keep these under the carpet

 

[shinbits]

Okay… although I have no explicit studies on impala speed you should be able to pull together what you have learned so far to understand the bigger picture.

Well, any animal would do. Pick any bird or mammal. Are there any studies or anything that show natural selection resulting in animals with improved performance in the entire population?

 

[Jet Black]

Well, any animal would do. Pick any bird or mammal. Are there any studies or anything that show natural selection resulting in animals with improved performance in the entire population?

yeap. quite alot actually.

 

[AnEmpiricalAgnostic]

A mutation may spread through a population, whether it does or doesn't is only very slightly influenced by the survival advantage that the mutation may bestow.

Throwing around words like “slightly” isn’t even a valid objection to the discussion at hand. As long as there is an advantage of any sort it is enough for a selection pressure to act upon. The only thing the advent of “slightly” gives you is more time. We already discussed this when talking about blind eagles compared to eagles with mediocre sight. The more extreme the detrimental trait the faster and harder selection pressure acts against it. Whether a trait offers a slight advantage or great advantage it will eventually proliferate throughout the population. This is dramatically illustrated in the sickle cell anemia example.

The probability an animal such as an impala is the result of a number of small genetic mutations and natural selection can be and has been calculated. The chance of this happening is a function of the chance the mutation occurs in the first place, and then the chance the mutation survives and is passed onto the the population.

To support the claim that animals are the result of evolution, you need to be able to quantify statistically that this is feasible.

You aren’t ready for this level of discussion yet. Please stick to the discussion at hand and we will eventually move to more advanced tops once everyone understands the fundamental concepts first.

 

[Micaiah]

Fine. The first step would be to quantify the probability of such an event is to quantify the survival advantage a mutation would typically provide. Your estimate please.

 

[shinbits]

yeap. quite alot actually.

I guess you're waiting for me to ask for a link.

Can u please post a link?

 

[AnEmpiricalAgnostic]

Well, any animal would do. Pick any bird or mammal. Are there any studies or anything that show natural selection resulting in animals with improved performance in the entire population?

Why don’t we use the sickle cell anemia example for this purpose. It’s a little more complicated than the other examples we have been working with but it offers a modern real life example and it will help pull your mind away from using only physical attributes like strength and speed.

Do you understand why in areas where malaria is prevalent populations have a high instance of sickle cell anemia?

Edited to add a link: http://sickle.bwh.harvard.edu/malaria_sickle.html

 

[Micaiah]

Sickle cell anemia is not the kind of mutation required to explain common descent. If your point is that beneficial mutations can be passed onto a populations, then on that we can agree.

I await your estimate requested previously.

 

[Jet Black]

I guess you're waiting for me to ask for a link.

Can u please post a link?

sorry no, that's what university libraries are for Really, I think you should actually head into a university library and go and find some of this stuff for yourself. links and websites are all well and good, but a bit of hard graft is even better, and really makes you realise the magnitude of the stuff out there.

 

[shinbits]

Do you understand why in areas where malaria is prevalent populations have a high instance of sickle cell anemia?

Edited to add a link: http://sickle.bwh.harvard.edu/malaria_sickle.html

If I'm correct, I think it has something to do with malaria affecting a red blood cell's ability to take transort oxygen.

Correct?

 

[Jet Black]

Sickle cell anemia is not the kind of mutation required to explain common descent. If your point is that beneficial matations can be passed onto a populations, then o that we can agree.

I await your estimate requested previously.

stop shifting the goalposts and hiding from your own shoddy arguments. It's really obvious, we can all see what you are doing, we aren't stupid Micaiah

 

[shinbits]

sorry no, that's what university libraries are for Really, I think you should actually head into a university library and go and find some of this stuff for yourself. links and websites are all well and good, but a bit of hard graft is even better, and really makes you realise the magnitude of the stuff out there.

You just said there was tons of stuff on this.......

 

[Jet Black]

If I'm correct, I think it has something to do with malaria affecting a red blood cell's ability to take transort oxygen.

Correct?

well when one has no sickle cell alleles, the blood cells are the normal donutty round shape (they make me think of a mint actually) and are squashy, so have no problem getting round the capillaries. When one has two sickle cell alleles, then the cells become rigid and shaped like a sickle (hence the name) This means that the cells cannot transport oxygen as well, and have a hard time getting through all the capillaries. When one has a single sickle cell and a single normal allele, then most of the time, the cells look normal, but when oxygen levels are low, the cells sickle. Now when the malarial parasite enters the blood cells, they use up the oxygen, and so the cells sickle and kill the parasite. This stops people with one allele from being infected, and it stops the parasite from causing haemolysis.

 

[Jet Black]

You just said there was tons of stuff on this.......

there is. University libraries aren't small places you know (well not in decent universities anyway)

just to clarify, by "sorry no" I didn't mean I can't, I meant I'm not going to.

 

[shinbits]

well when one has no sickle cell alleles, the blood cells are the normal donutty round shape (they make me think of a mint actually) and are squashy, so have no problem getting round the capillaries. When one has two sickle cell alleles, then the cells become rigid and shaped like a sickle (hence the name) This means that the cells cannot transport oxygen as well, and have a hard time getting through all the capillaries. When one has a single sickle cell and a single normal allele, then most of the time, the cells look normal, but when oxygen levels are low, the cells sickle. Now when the malarial parasite enters the blood cells, they use up the oxygen, and so the cells sickle and kill the parasite. This stops people with one allele from being infected, and it stops the parasite from causing haemolysis.

Okay.

What does this have to do with natural selection?

 

[shinbits]

just to clarify, by "sorry no" I didn't mean I can't, I meant I'm not going to.

why? this is what your whole point starts to lead up to.


Basically, if there's no evidence that animals have been improving in performance over time, then there's no evidence for natural selection and it's supposed role in evolution of a population into a more advanced or adapted species.

 

[AnEmpiricalAgnostic]

If I'm correct, I think it has something to do with malaria affecting a red blood cell's ability to take transort oxygen.

Correct?

For our purposes the bottom line for malaria is that it attacks the red blood cells in the host and can easily kill them (especially children). However, for people that carry the sickle cell trait it’s a different story:

Sickle trait provides a survival advantage over people with normal hemoglobin in regions where malaria is endemic. Sickle cell trait provides neither absolute protection nor invulnerability to the disease. Rather, people (and particularly children) infected with P. falciparum are more likely to survive the acute illness if they have sickle cell trait. When these people with sickle cell trait procreate, both the gene for normal hemoglobin and that for sickle hemoglobin are transmitted into the next generation.

People with full blown sickle cell disease often die also. What makes this particular example so interesting is that while the detrimental sickle cell trait is killing off individuals in the population (which should eventually lead to the removal of that trait) the malaria problem is also acting as a strong selection pressure on those without a sickle cell trait at all.

In the center are people with sickle cell trait who possess one gene for normal hemoglobin and one gene for sickle hemoglobin. These children are more likely to survive their initial acute malarial attacks than are people with two genes for normal hemoglobin. Also, they suffer none of the morbidity and mortality of sickle cell disease. Therefore, the people with sickle cell trait are more likely to reach reproductive age and pass their genes on to the next generation

So here you have a balancing act that natural selection has created. I know it’s a bit more complicated since there are two factors working simultaneously here but I think you’re ready.

 

[Dannager]

why? this is what your whole point starts to lead up to.


Basically, if there's no evidence that animals have been improving in performance over time, then there's no evidence for natural selection and it's supposed role in evolution of a population into a more advanced or adapted species.

I think Jet Black realizes, as I am beginning to, that you are basically on the threshold. You are looking out over a wealth of information that you previously did not have and are actually intellectually honest enough to not back away from it. We can provide you with our sources all day long but they will always be our sources until you go out and do the work for yourself. I think a university library would be a good place to look. You won't be getting partial, bank-on-the-controversy books like you would find on the Barnes & Noble display table. The resources you'll be able to find will be scholarly in nature and based on current understanding.