Evolution Opponents Lose Kansas Board Majority

[bandwagon]

And that set would need to be homochiral, all the monomers of the same chirality. And we don't have any idea how that would happen.


No. It has to select the "correct" monomers every single time, or the replication will stop. Period. And if you're suggesting that the original ribozyme wasn't stereoselective, then that just bumps the problem forward.

You mistook my meaning on this point. Yes the correct monomer has to be selected for every single nucleotide in the whole sequence on a given RNA molecule. I meant that the correct selection for a whole RNA molecule could happen by chance occasionally. But the primordial RNA could be very small, just a few nucleotides, because as I say, the sequence has no function yet. To have the potential for replication there would need to be a minimum of one pair. Taking the case of RNA with a total of 2 pair, the chances of correct selection leading to replication would be 1:16.

Yes, they would need to be homochiral to begin with. Well, isn't polymerisation with homochiral nucleotides slightly more stable*, so there is a greater chance over time that the "mother" RNA, the one that first started replicating and progressed, would have been homochiral. Under critical conditions even a slight difference in stability would cause a threshold effect, leading to a dominance of homochiral RNA.



*I have only a vague memory of that and could be wrong. Let me find some info.

[ArmchairGeneral]

You mistook my meaning on this point. Yes the correct monomer has to be selected for every single nucleotide in the whole sequence on a given RNA molecule. I meant that the correct selection for a whole RNA molecule could happen by chance occasionally. But the primordial RNA could be very small, just a few nucleotides, because as I say, the sequence has no function yet. To have the potential for replication there would need to be a minimum of one pair. Taking the case of RNA with a total of 2 pair, the chances of correct selection leading to replication would be 1:16.

That would be plausible, if such a small RNA is capable of replication to begin with, which is something I don't know.

Yes, they would need to be homochiral to begin with. Well, isn't polymerisation with homochiral nucleotides slightly more stable*, so there is a greater chance over time that the "mother" RNA, the one that first started replicating and progressed, would have been homochiral. Under critical conditions even a slight difference in stability would cause a threshold effect, leading to a dominance of homochiral RNA.



*I have only a vague memory of that and could be wrong. Let me find some info.

Hm. If that is so, it would make sense. But (and I'm making an educated guess here), I believe any such stability is on such a small scale that it is completely overwhelmed by much larger forces which tend to randomize any chiral molecules. I seem to recall that it has something to do with the weak atomic force, which is, after all, called the weak force for good reason. I believe I have read that even completely homochiral molecules have a tendency to racemize over time, which seems like it would rule the possibility of long term homochiral selection out. At least in the vast majority of molecules. The discoveries regarding serine octamers makes it plausible to me that there are other compounds out there with stereoselective properties. I wonder if there are any people playing with serine to try to make optically pure compounds?

On another note, are you aware of any ribozymes that are able to replicate segments without using activated ribonucleotides? Activated nucleotides are bonded to high energy ATP molecules by kinase enzymes, providing the needed oomph to get the replication reaction going. Just another question I have about the whole idea, wondered if you could shed any light on it.

[dalem]

Are you telling me that evolution theory does not predict a common ancestor?

If it does, then i'm hardly wrong.

Evolutionary Theory is about modification BY DESCENT.

All that it "predicts" is how life changes over time, not where it came from.

-dale

[bandwagon]

On another note, are you aware of any ribozymes that are able to replicate segments without using activated ribonucleotides? Activated nucleotides are bonded to high energy ATP molecules by kinase enzymes, providing the needed oomph to get the replication reaction going. Just another question I have about the whole idea, wondered if you could shed any light on it.

I have not seen it said that it happened without activated nucleotides, but I wonder whether the bonding to an activated base could have happened without an enzyme if there was a suitable source of energy. UV light or lightening, but this also casuses degradation as you pointed out. I like the idea of concentrated pockets in ocean floor rock cavities in hot volcanic areas, but the heat required produce activated nucleotides would be to high for polymerisation. There was also that theory that energy could be derived from redox reactions involving minerals in the rock surface, such as iron sulphide or pyrites, perhaps as an autocatalytic set.

Thanks for the compliment earlier. I am not a biochemist and know more about nipples (I see loads every day ) but like you I 've always found this stuff fascinating.

[Bill]

Half the problem is that your definition of "far more capable preditor" revolves around some kind of cartoon like Discovery Channel "Worlds Meanest Preditors" caricature. You think that "more capable preditor" must always mean longer and longer teeth, thicker and longer arms and thicker and thicker armor.

Indeed that's the case the vast majority of the time IMO.

Longer teeth, bigger size, faster movement, greater agility, greater endurance, thicker armor(skin or fur or exoskeleton), more powerful venom, greater bite/grip strength, greater leaping ability...all these things are how predators are measured. Just like we use these sorts of things to measure the abilities of a soldier.(something i know something about).

You are not even contemplating that improvements have downsides as well as upsides. For exampe you have not even considered the fact that having forearms too long and too heavy will slow a bipedal therapod down, or that having armor too thick will also slow a preditor down. You could have the meanest looking preditor out there, but if it cannot even catch up to it's prey then it's useless. It is more than likely that therapod arms are the optimal length. Simply saying that they should be longer has absolutely no evidence going for it.

Bigger arms would indeed add mass, but that would lead to increased lower body strength as the muscles developed to a larger size to bear the extra weight. And you don't need to be quite as fast or jump quite as far when you can reach out and grab something. The greater muscular density and mass of the legs would also increase the T-rex's ability to suffer battle damage with prey animals, and it's longer, more muscular arms would be excellent for fending off counter-attacks, and would themselves be more robust than the twigs T-rex is said to have had.

So yes, clearly a long-armed tyranousaur would be a far more capable predator. It would add grappling to it's bag of tricks. Grappling is a proven hunting skill all throughout the animal kingdom. One that the classical T-Rex couldn't do.

Whether evolution predicts that species will improve or not is irrelevant to the fact that a long armed T-rex is obviously a better predator, in all demonstrable ways.

No it's not the same. But the fact is that if therapod's small arms are pointless then NATUARL SELECTION has failed. Saying it's speciations responsibility doesn't make it so. At the end of the day it is natural selection that will determine the optimal length of therapod dinosaur arms. So immediately you should think "hmm maybe my assumption that longer arms would be a huge advantage might be misplaced" rather than thinking natural selection has failed.

According to Armchair natural selection is a result of accidental mutation, not of what works best or societal pressures(which i always thought was the case), so therefore whether t-rex's arms are long or short appears to be incidental as long as it can still feed itself. So no, one could not opine that the stub-arms were optimal, only that they're not detrimental.

Seems like i'm getting some differing opinions of which way is up from all the experts on this thread....LOL.

[Bill]

Evolutionary Theory is about modification BY DESCENT.

All that it "predicts" is how life changes over time, not where it came from.

-dale

Tha'ts not my understanding of the issue because we've heard again and again about this lovely common ancester -in this thread, many times- that all life sprung from.

So if the common ancester is not a theorum of evolution(which im sorry, if its not it really ought to be- big bang can at least point to the singularity as the common ancestor, and tell us where it was even), what's the premise for some of the posters on this thread insisting a common ancestor is a legitimate hypothesis?

[Bill]

I have not seen it said that it happened without activated nucleotides, but I wonder whether the bonding to an activated base could have happened without an enzyme if there was a suitable source of energy. UV light or lightening, but this also casuses degradation as you pointed out. I like the idea of concentrated pockets in ocean floor rock cavities in hot volcanic areas, but the heat required produce activated nucleotides would be to high for polymerisation. There was also that theory that energy could be derived from redox reactions involving minerals in the rock surface, such as iron sulphide or pyrites, perhaps as an autocatalytic set.

Thanks for the compliment earlier. I am not a biochemist and know more about nipples (I see loads every day ) but like you I 've always found this stuff fascinating.

So if im reading you right, you believe abiogensis is correct, yes?

[bandwagon]

So if im reading you right, you believe abiogensis is correct, yes?

Yessir. In anticipation to your next question, yes, in view of the lack of evidence, it is a faith.

[Bill]

The fossil is intact. They can compare that with snakes. A reptile that looks very very similar to a snake rather than a lizard...that must be a snake. That's the problem. You don't.(understand)

That's some real shaky reasoning dude, and there is FAR from universal agreement even among biologists as to whether or not your above OPINION is even the case.

There are three sects(that i read about last night).

1) believes what you just said.
2) believes that ONLY with DNA proof can that determination be made
3) believes that DNA and similar traits are required

So only under 1 of the 3 view on this matter are you correct in this issue.
Both type 2 and type 3 would be unswayed without DNA evidence....just like i am.

So perhaps it'd be best to stop passing things off as fact and telling me i don't understand when there isn't even agreement among the experts, and when you are only passing off one of the three scientific views on the subject.(which after reading up on a lot of this stuff last night it seems to be a trend among many on this thread- there is widespread disagreement among many scientists wrt all kinds of details of all the things we've been debating here)

And finally, is there such DNA evidence proving that the legged 'snake-like' lizard is acutally a snake, or does it just look like one?

[bandwagon]

Longer teeth, bigger size, faster movement, greater agility, greater endurance, thicker armor(skin or fur or exoskeleton), more powerful venom, greater bite/grip strength, greater leaping ability...all these things are how predators are measured. Just like we use these sorts of things to measure the abilities of a soldier.(something i know something about).

All, a few or none of those. It depends entirely on their niche.

[Bill]

Yessir. In anticipation to your next question, yes, in view of the lack of evidence, it is a faith.

I'd say a stretch....but OK, you're an American, you can believe in the KFC bunny that brings friend chicken on Columbus day morning for all the kiddies if you want.

[bandwagon]

According to Armchair natural selection is a result of accidental mutation, not of what works best or societal pressures(which i always thought was the case), so therefore whether t-rex's arms are long or short appears to be incidental as long as it can still feed itself. So no, one could not opine that the stub-arms were optimal, only that they're not detrimental.

Seems like i'm getting some differing opinions of which way is up from all the experts on this thread....LOL.

No. Accidental mutation only provides variety. Selection only happens in the face of competition.

[bandwagon]

I'd say a stretch....but OK, you're an American, you can believe in the KFC bunny that brings friend chicken on Columbus day morning for all the kiddies if you want.

Show me direct evidence for the existence of a creator and I might change my mind. Otherwise the steamroller of discovey will soon show that the bible is metaphorical rather than literal.

[Bill]

All, a few or none of those. It depends entirely on their niche.

Would you agree that the more of the things on that list that are present the better the hunter in question will be?

A snake that constricts is good.

But a snake that constricts and has arms with big-asssed claws, heavy armor plate, venom, and huge tearing teeth....or even a bigger brain is FAR better.

You know, like a Komodo Dragon.

This is not to say evolution predicts such a beast should emerge because of 'natural pressures'(apparently its a lot more random than i though according to current thinking which took hold in 1998 according to what i read last night), it's just to say that said predator would clearly be better.

Longer arms are just a better weapons system, and would give a T-rex just one more way to attack his enemy.

Were i an Intelligent designer- ie if im gonna design a T-rex from the ground up to be the best- i assure you it would have much longer arms with dual opposable thumbs and six fingers ALONG with all it's other already present traits. I'd probably make it spit poison like a cobra too.

It's really like adding a co-ax to a tank, or putting a bigger engine in it, or giving it more armor, etc. The more 'weapons' or 'armor' or 'mobility' you've got the better the predator- or tank- in question is. The only drawback is logistics, ie fuel consumption(which equates to metabolism/rate of energy consumption in a living beast).

So to the fella that scoffed 'except that a snake doesnt have tracks', well, a snake has the animal kingdom equivelant to tracks. Tracked vehicles ARE called earth crawlers for a reason, y'know?

[dalem]

So no, one could not opine that the stub-arms were optimal, only that they're not detrimental.

[Obi-wan voice]
You have taken you're first step into a larger world.
[/Obi-wan voice]

-dale