Video: Randomness vs Evolution

[Ophiolite]

that is the main question. we know for instance that many proteins are very different from each other. so we need many mutations to such conversion in these specific cases.

How many? You are saying too many, but you have failed to state how many are actually involved, or to state how many would be too many. (In Lallans Scot I would say "you wis haverin". )

 

[xianghua]

How many? You are saying too many, but you have failed to state how many are actually involved, or to state how many would be too many. (In Lallans Scot I would say "you wis haverin". )

i think that it can be as many as 100-200 amino acids changes. depend on the proteins involve. even homologous proteins (similar proteins) can be different from each other at about 70% of their sequence.

 

[Kylie]

because in such a case the chance is far more higher.

Chance for what?

but if we need many changes at once (many amino acids changes) its a problem.

Why?

And regarding these changes, I have two questions.

How many changes at one time are required?
How large does each change need to be?

 

[xianghua]

Chance for what?

to evolve a new function.

How many changes at one time are required?

depend on the function but it may requires up tp 100-200 changes at once.

How large does each change need to be?

see above-. 100-200 depend on the function. for instance: globin and histone have similar length (about 100-150 aa). i will take many amino acids to change a globin into histone or vice versa.

 

[pitabread]

depend on the function but it may requires up tp 100-200 changes at once.

Citation needed.

 

[xianghua]

Citation needed.

globin sequence is very different from histone sequence. this is the sequence of human beta globin:HBB - Beta-globin - Homo sapiens (Human) - HBB gene & protein

10 20 30 40 50
MVHLTPEEKS AVTALWGKVN VDEVGGEALG RLLVVYPWTQ RFFESFGDLS
60 70 80 90 100
TPDAVMGNPK VKAHGKKVLG AFSDGLAHLD NLKGTFATLS ELHCDKLHVD
110 120 130 140
PENFRLLGNV LVCVLAHHFG KEFTPPVQAA YQKVVAGVAN ALAHKYH

the histone one:

HIST1H3A - Histone H3.1 - Homo sapiens (Human) - HIST1H3A gene & protein

10 20 30 40 50
MARTKQTARK STGGKAPRKQ LATKAARKSA PATGGVKKPH RYRPGTVALR
60 70 80 90 100
EIRRYQKSTE LLIRKLPFQR LVREIAQDFK TDLRFQSSAV MALQEACEAY
110 120 130
LVGLFEDTNL CAIHAKRVTI MPKDIQLARR IRGERA

 

[pitabread]

globin sequence is very different from histone sequence. this is the sequence of human beta globin:

You're claiming that the changes have to happen all at once. That is what I'm asking about. Why would the changes need to happen in a single step? What is your source for that claim?

 

[Kylie]

to evolve a new function.

Please tell me how you figure that the chance for a new function in a protein to evolve is higher when that protein has no lower limits on its size.

depend on the function but it may requires up tp 100-200 changes at once.

Do you have a source to back up this claim?

see above-. 100-200 depend on the function. for instance: globin and histone have similar length (about 100-150 aa). i will take many amino acids to change a globin into histone or vice versa.

No, this is a different question. There is a difference between how many changes are required and how big each of those changes needs to be.

 

[xianghua]

You're claiming that the changes have to happen all at once. That is what I'm asking about. Why would the changes need to happen in a single step? What is your source for that claim?

because we know that if we want to evolve 2 new binding sites for insatnce we will need many changes. say that there is a protein that bind 2 molecules. even if we will evolve the first binding site it will be usless without the second binding site.

 

[xianghua]

Do you have a source to back up this claim?

here is one paper about atp binding:

Functional proteins from a random-sequence library

about 45 amino acids are need to bind atp molecule. and many proteins needs at least2-3 sites.

 

[Kylie]

here is one paper about atp binding:

Functional proteins from a random-sequence library

about 45 amino acids are need to bind atp molecule. and many proteins needs at least2-3 sites.

Evolution isn't random.

And are you suggesting that evolution must have gone from no binding to binding exactly the way it is today in just one step?

 

[xianghua]

Evolution isn't random.

And are you suggesting that evolution must have gone from no binding to binding exactly the way it is today in just one step?

let me put it this way: what make you think that all the functional proteins are near each other so you can change any functional protein into other functional protein just by few changes every step? think about this too: can you change your hand watch by small steps and get a new systm like a cell-phone by changing a single part each step?

 

[Kylie]

let me put it this way: what make you think that all the functional proteins are near each other so you can change any functional protein into other functional protein just by few changes every step? think about this too: can you change your hand watch by small steps and get a new systm like a cell-phone by changing a single part each step?

I don't think you understand how it works. We are dealing with a population of organisms here. Imagine that each one of them made a very slight change. Some of the changes wouldn't work at all, and those individuals would die. Some of the changes would work, but not as good as the original. THose individuals would have a reproductive disadvantage. Some changes would be neutral and have no bearing on the reproductive fitness. Other changes would be beneficial, and the individuals with those changes would have a reproductive advantage.

Obviously, those individuals with the beneficial changes would be more likely to produce offspring, and those offspring would have the beneficial change genes passed on to them.

Now, repeat this many times over many generations. Do you not see how this can lead to large changes?

 

[xianghua]

Obviously, those individuals with the beneficial changes would be more likely to produce offspring

sure. the question is how many mutations we need to some changes like evolving a protein\s that can make amino acids or other function. as i said- we need many amino acids changes to evolve such proteins.

 

[Kylie]

sure. the question is how many mutations we need to some changes like evolving a protein\s that can make amino acids or other function. as i said- we need many amino acids changes to evolve such proteins.

The mutations happen bit by bit over many generations.

I literally could not have been clearer about this.

 

[pitabread]

because we know that if we want to evolve 2 new binding sites for insatnce we will need many changes. say that there is a protein that bind 2 molecules. even if we will evolve the first binding site it will be usless without the second binding site.

How do you know any of this is true? You seem to making specific, unsupported assumptions about how you think evolution works or how things proceed.

It reminds me of the creationist who used to post how half-flippers/half-legs would be a useless feature, until I showed him examples of such things on living animals.

 

[xianghua]

How do you know any of this is true? You seem to making specific, unsupported assumptions about how you think evolution works or how things proceed.

It reminds me of the creationist who used to post how half-flippers/half-legs would be a useless feature, until I showed him examples of such things on living animals.

here is a simple way: if you will remove parts from your cell-phone eventually you will end up with no function at all. right? the same is with proteins or biological systems. if you will remove some genes\amino acids you will end up with no function.

 

[pitabread]

here is a simple way: if you will remove parts from your cell-phone eventually you will end up with no function at all. right? the same is with proteins or biological systems. if you will remove some genes\amino acids you will end up with no function.

So this is just something you are making up and you don't have an actual source for. Understood.

 

[Kylie]

here is a simple way: if you will remove parts from your cell-phone eventually you will end up with no function at all. right? the same is with proteins or biological systems. if you will remove some genes\amino acids you will end up with no function.

Cellphones were designed, not evolved. And cell phones don't reproduce. ANd cell phones don't have variation when they reproduce. Your analogy is flawed and doesn't work.

 

[xianghua]

So this is just something you are making up and you don't have an actual source for. Understood.

here is one example i already gave:

Construction of a minimum-size functional flagellin of Escherichia coli.

so any protein will be non-functional if we will remove some parts of it.