Researchers Trace Evolution To Relatively Simple Genetic Changes

[wit>trope]

No, now you ARE wrong....

lol. You said I was wrong before but then you edited your post and admitted I was right. I expect you'll do the same again

I said, what's the probability that ANY two people SHARE THE SAME BIRTHDAY.

No you didn't. Your original problem statement was:

"You're at a party, and there are 23 people there. What is the probability that one of those 23 will share your birthday?"

 

[Mise]

Gah, I knew I shouldn't have bothered...

1) I wanted you to work out the probability of 1 person sharing your birthday
2) I wanted you to work out the probability of ANY two people sharing a birthday
3) I wanted you to compare those probabilities
4) I wanted you to compare the probability of getting ONE type of fish with the probability of getting ANY type of fish.

EDIT:
The prob of getting ONE type of fish is very small, but if that ONE type didn't happen, ANOTHER type would have happened, or another or another, or MAYBE no fish at all -- just like if Mr Bloggs didn't win the lottery, someone else would have won it, or someone else, or someone else, or MAYBE no-one.

lol. You said I was wrong before but then you edited your post and admitted I was right. I expect you'll do the same again

Incidentally, my confusion was that I didn't realise that I had assumed that in deriving the formula for the probability of no-one having the same birthday -- it was, in effect, two different ways of expressing the same probability.

EDIT2: It seems to make sense now - the probability that no-one has the same birthday requires them all to have different birthdays

 

[anarres]

Hmm. Aren't we avoiding the issue dear creationists?

This all goes back to the claim that maths can prove evolution is false.

Do MeteorPunch and cierdan still claim this crazy nonsense????

If so, please say so and I can rebut your claims.

In not, please say so, and I will stop reading these replies in the vain hope that there will be a MATHMATICAL response to any of my posts.

I am not here to score points, I am not even here because I enjoy it (really I don't enjoy this thread). I am here because there is a tiny chance that misinformation could do harm to people like Bozo. I want to protect the Bozos of the world.

Edit: Bozo I love you! My secret is out.

 

[Bozo Erectus]

Its also possible that one year on his birthday, Mr Bloggs will win the lottery and then be eaten by a fish as he splashes around in the water shouting 'Yahooo! Im rich!"

 

[Bozo Erectus]

Edit: Bozo I love you! My secret is out.

I thought we vowed to never cheapen our love by discussing it in front of strangers who cant understand us

 

[MeteorPunch]

I've lost interest as well. I'll just wait around for the next evolution post which will statistically occur in a couple days.

 

[Yom]

I was hoping that this thread wouldn't turn into another evolution vs. creationism debate, but, of course, it did.

Let me rebut some misconceptions.

There is a fundamental mathematical problem with the theory of evolution. It's fine mathematically speaking to suppose that changes occurred that are the results of one or even a few bits of the genetic code mutating. But one or a few bits of genetic code mutating cannot make a lizard grow wings and fly. So while changes like much stronger armor or the loss of armor or much longer necks can theoretically occur through evolution. Changes like say a dog mutating to grow wings and fly are just statistically impossible -- even after a google generations or a google number of years. You can't suppose that mutations piled together to form the wings that made certain animals able to fly because the first in this long series of mutations wouldn't be favored by natural selection in the first place -- i.e. having 1 millionth (or 1 thousandth or whatever figure) of the genetic progression towards a wing would not be favored by natural selection; if anything it would be disfavored by natural selection.

The problem is that there ISN'T! 1 thousandth (or 1 millionth or whatever figure) of the genetic progression towards a wing is not favored by natural selection. It's completely useless. One round of mutations wouldn't produce a wing-like appendage anyway but even assuming that it did, what use would it have natural-selection wise? It wouldn't help you fly. You can't fly with something that doesn't function at all as a wing. If anything it'd be selected AGAINST because of the unnecessary added weight. I think some people have this idea that natural selection has some mystical character to it that guides it to certain long term goals. But the mechanism by which natural selection functions is purely from generation to generation. Long term effects do result. But this kind of long term effect just can't result from it.

Just use your head!

Let's suppose you had something that was 1 thousandth of the constitution of a functioning wing. Well what good does it do? Unless it actually functions, it won't do you any good and will just be extra weight which natural selection will actually select against.

No it doesn't. It boils down to some basic mathematics. There is no plausible account ANYWHERE in the literature that I have read which shows how a single round of mutations constituting a genetic progression towards functioning wings is favored by natural selection. All the evidence would seem to indicate that if anything it would be DISfavored by natural selection. Thus the probability that each out of thousands or millions of rounds of mutations would occur necessary for the development of functiong wings can be calculated to be AT LEAST as low as the result when calculating the probabilty of each round independently and multiplying them (in reality the probability will be lower). The resulting probability is astronomically low. Even after a google generations (for those of you who don't know google is actually a defined number), it's statistically impossible for it to happen.

First of all, mathematics doesn't have anything to do with this unless you're talking about the probability of any mutation in spermatogenesis or oogenesis (provided we're talking about evolution after animals evolved), which is quite high. DNA mutations happen all the time to create new traits, but only those that are beneficial are kept, as the deleterious ones destroy the cell (before it gets a chance to fertilize an egg cell, if it's a sperm cell, or before it gets fertilized by a sperm cell, if it's an egg cell). For instance, a mutation in DNA could cause the production of a new protein in a small dinosaur, causing its arms to have hollow, light bones. Since the lightness lowers its metabolism (less to support means less calorie intake required) as well as making it faster, the trait will be selected for. Over a number of generations, the whole species will have lighter bones. That would most likely be the first step to evolving wings. How it could have evolved after that has also been documented. There are many possible methods; it could have originated from tree-dwelling creatures developing the ability to glide and then fly, or from bipedal animals living on the ground.

Here is a site that spells out how the evolution of wings could occur. A lack of imagination is not an adequate argument against evolution. In fact, it is a logical fallacy: argumentum ad ignorantium.

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

http://www.ucmp.berkeley.edu/vertebrates/flight/evolve.html

All I had to do was type in "wings evolution" (without quotation marks) into google, and this was the first page that came up. You cannot say that you have never seen a way that the evolution of wings could occur.

 

[wit>trope]

Incidentally, my confusion was that I didn't realise that I had assumed that in deriving the formula for the probability of no-one having the same birthday -- it was, in effect, two different ways of expressing the same probability.

EDIT2: It seems to make sense now - the probability that no-one has the same birthday requires them all to have different birthdays

Yes that's right.

But you still have confusion on another front. Lemme explain. Suppose you are in a room and part of an experiment whose nature is not known to you. So you don't know who is conducting it or any purpose it might have. But what you are told is that will be given a series of 10,000 numbers and that you are to come to a reasonable belief as to whether that series of numbers was generated randomly or not (don't assume it involves computer science -- you aren't told anything about how they were generated). Now if the series of 10,000 numbers (let's make the numbers integers between 0 and 9 inclusive) was truly generated randomly, even though any particular sequence of 10,000 numbers has an equal probability of being generated than any other particular sequence of 10,000 numbers that does NOT mean that every class of sequences is as likely to occur as any other class of sequences. For example if the series of 10,000 numbers is truly generated randomly it is expected that when it forms a decimal numeral with the first in the series being the first digit and so on, that the resulting number will exhibit the property of being a normal number:

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

If the resulting number does not show signs of that property (for example if the digits repeated your wedding anniversary over and over again), then that would be evidence that the series was not randomly generated (even if it were a normal number that wouldn't mean that the series was for certain randomly generated; but if it's not a normal number then the series in all probability would not have been randomly generated)

 

[wit>trope]

Here is a site that spells out how the evolution of wings could occur.

All I had to do was type in "wings evolution" (without quotation marks) into google, and this was the first page that came up. You cannot say that you have never seen a way that the evolution of wings could occur.

Um what I said was that I never saw any plausible account as to how wings would have evolved. In fact your site acknowledges that this issue is "most perplexing" One of the four proposed hypotheses on the first page of the article is acknowledged by the author to be not falsifiable which ironically is the same criticism sometimes leveled against creation science. Also ironically this non-falsifiable hypothesis is the very one that someone in this thread proposed! Another of the four hypotheses is nonsensical. And another actually begs the question in that it assumes that gliding creatures have evolved (this is not the author's fault since he wasn't discussing the question we are discussing here). One of the four is not nonsensical, but is it plausible? Well on the second page the article says that there is NO known plausible account!:

"But we really can't conceive of finding real evidence that will decide the plausibility of these hypotheses."

So your website actually SUPPORTS what I said and strengthens it. Now I can say not only that I do not know of any plausible account but that even a top evolutionist ADMITS that there is no known plausible account!

 

[Mise]

Yes that's right.

But you still have confusion on another front. Lemme explain. Suppose you are in a room and part of an experiment whose nature is not known to you. So you don't know who is conducting it or any purpose it might have. But what you are told is that will be given a series of 10,000 numbers and that you are to come to a reasonable belief as to whether that series of numbers was generated randomly or not (don't assume it involves computer science -- you aren't told anything about how they were generated). Now if the series of 10,000 numbers (let's make the numbers integers between 0 and 9 inclusive) was truly generated randomly, even though any particular sequence of 10,000 numbers has an equal probability of being generated than any other particular sequence of 10,000 numbers that does NOT mean that every class of sequences is as likely to occur as any other class of sequences. For example if the series of 10,000 numbers is truly generated randomly it is expected that when it forms a decimal numeral with the first in the series being the first digit and so on, that the resulting number will exhibit the property of being a normal number:

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

If the resulting number does not show signs of that property (for example if the digits repeated your wedding anniversary over and over again), then that would be evidence that the series was not randomly generated (even if it were a normal number that wouldn't mean that the series was for certain randomly generated; but if it's not a normal number then the series in all probability would not have been randomly generated)

You mean to say that a randomly generated set of digits will more likely than not appear random, e.g. 5494213876, as opposed to an obvious sequence like 012345679? Agreed. I don't see how that changes anything; if anything it merely backs my point up. You assume that a particular type of fish is in some way special, like the sequence 0123456789 - that's true, a SPECIAL type of fish is SPECIAL. But ANY type of fish, e.g. 5494213876 or 8187654921 or 7554913568 is NOT special, it's completely random. That was the point I was trying to get across -- you are looking at the probability of getting a particular type of fish, or a particular type of number, or a particular person's birthday, or a particular person winning the lottery, when you should really be looking at the probability of getting ANY type of animal (say, a fish), ANY type of number (say, a prime number), ANY (say) two people's birthday, or ANYone winning the lottery.

As I said before, if we multiply the probability of getting a particular fish in time dt (small) by the total number of different types of fish possible (large), and then integrate over however long geological evidence says fish took to evolve, you get a large probability. I mean, think of how many ways you could possibly make a fish! To use an analogy, think of how many ways you could walk to the supermarket -- the probability of going any one particular way is very low, but you are most likely going to get there, unless you get run over (or have sex )

 

[Birdjaguar]

Everyone is a evolutionist even the creationist. Noone denials AFAIK that natural selection is a factor in nature. Even Christians from the beginning agree with Darwin on this issue as they saw the different varities of a species. The different is evolutionist believe their little theory explains and created everything while those of ID see it's limits.

While this is interesting they found the switch that turn on and off these plates doesn't say nothing how did this switch evolved the start with. While It easy to see that when I flip a switch on the wall a light on the ceilling turn on and off yet this is because hidden behind the walls an intelligent being wired the switch and the light so this would happen on purpose and not by accident.
I'm sure as time passes they will find more switches in the genetic code yet if only they can find the ape-man switch. Where could that switch be?

I read this post this morning and have been thnking about it; little did I realize this thread would add 80 posts before I got home from work!
I think we can lump folks into three basic groups: Young earth creationists (7 day creation 6000 years ago); Old earth creationists (limited evolution, ID, earth billions of years old); and evolutionists who don't believe that god created the universe.

As science continues to produce more and more evidence for evolution the bible literalists are in the toughest position. They can only rely on their faith to support their views. As we have seen here many times supporting the bible through bible quotes is more a statement of faith than reason. I think that the move to ID is an attempt to embrace "acceptable" science and get away from reliance on the faith only position of lliteralists. But because ID believers must end up in a position that supports ID, they must reject some fundamental thinking that science is built on. The previous 60 posts on probability are a testament to this idea. The science adopted by ID is necessarily twisted to fit the already determined goal of supporting ID. All other science must be rejected or ID must be rejected. I would expect the bickering over whose science is real to continue for many years. The advantage of the evolutionists is that they do not have a pre determined outcome, but will follow the twisty path of observation and measurement.

In the long run science will not lose the arguments about the nature of the universe. Religions (including christianity) will reconfigure their beliefs (and theology) to fit. The "next" discussions will be about the creation point, or how does llife on other planets fit into god's plan, or what is the nature of a being that is outside the universe. The real questions for evolution: "Could the evolution of life process as we know it been planned?" or "Could it have happened by chance?" Were any of the processes of evolution laid down before the process started? Or did they all evolve?

 

[Mise]

and evolutionists who don't believe that god created the universe.

An important point here: I know many so-called evolutionists who believe that God created the universe (or, at the very least, that God exists). These beliefs are entirely consistent with science. Why? Because science ONLY deals with TESTABLE hypotheses; God, by it's very nature, is untestable, and therefore science does not deal with it at all. It's quite consistent to hold a belief in God and still be an "evolutionist". Either your definition of evolutionist needs expanding, or you need a fourth category for such evolutionists who believe in a God outside what we can measure.

 

[wit>trope]

Because science ONLY deals with TESTABLE hypotheses

Apparently not at least when it comes to evolution science since the article by an evolution scientist Yom linked to is devoted to discussion of UNtestable hypotheses. This is not just my opinion. The AUTHOR of the article ADMITS that he is discussing things that are UNtestable:

"But the problem is that neither is testable! . . . These hypotheses also cannot be tested directly. They are interesting ideas, and some may even be right. But we really can't conceive of finding real evidence that will decide the plausibility of these hypotheses."

If your definition of science is a true one then it would seem that evolution science is not truly science by your own definition!

Anyway, the point I was making in this thread was not about denying that some kind of evolution occurs but rather pointing out that some classes of things can't (statistically speaking) result from evolution. For example biological wheels cannot result from evolution. Wheels would be incredible useful but wheels have never evolved nor could they ever stastically speaking evolve as they belong to a class of changes that statistically speaking are astronomically unlikely to result merely from evolution. Wings, I argue also belong in the class of things that include wheels, that cannot result merely from evolution. When one observes in nature some features of some animals that belong to a class of things that are astronomically unlikely even after a google generations to result merely from evolution, then the scientific thing to do is to come to the conclusion that something other than or at least something more than evolution is responsible for it. In contrast the dogmatic thing to do would be to cling to evolution science and trying to avoid the fact ADMITTED by the evolutionist article Yom linked to that there are no known plausible accounts of how some things such as wings could have evolved.

 

[Mise]

Apparently not at least when it comes to evolution science since the article by an evolution scientist Yom linked to is devoted to discussion of UNtestable hypotheses. This is not just my opinion. The AUTHOR of the article ADMITS that he is discussing things that are UNtestable:

He was talking about wings. EDIT: I should say something here that he was talking about the answer to the question, "Why did wings improve the ability of the sub-species to survive." Evolution, OTOH, doesn't need to know why, all it needs to know is that it improved the ability of the sub-species to survive. Evolution doesn't concern itself with the "why" -- the scientist is speculating on something related to but not formally part of the theory of evolution. [/EDIT]

Evolution, OTOH, is testable. For example, an evolutionary sequence goes:
a, b, c, d, e, f, ?, h, i.
Evolution "predicts" that the "?" is a "g" -- we can "test" that by looking at geological evidence in the form of fossils and bones -- if we find a "g", the prediction of evolution is true, if not, it's back to the drawing board. Such predicted missing links in the evolutionary chain have been tested and proven in the past. This is what we talk about when we consider a "provable" evolution.

For example biological wheels cannot result from evolution. Wheels would be incredible useful

Again, YOU think they are USEFUL. Evolution does NOT "think" at all, it does NOT "decide" what is "useful". All that happens is:

1) some random mutation is made (EDIT: in other words, ANY mutation)
2) if it affects the population of the sub-species containing the mutation, it is subject to selective pressure
3) If it increases the ability of the sub-species to reproduce (for example, by making it easier to run away from it's predators [i.e. survive], by making it easier to reproduce, by making it easier to catch prey, etc etc etc) then the sub-species will increase in number through greater reproduction, and the sub-species lacking the mutation will reduce in number relative to the original species.

As you can see, the only reason a mutation is "beneficial" is if it ultimately enables the mutated sub-species to increase its population relative to the parent species. That's something that you REALLY have to understand in order to understand the nature of natural selection.

Your clinging to the assumption that wings are in some way special (like 0123456789) shows your lack of understand for what natural selection entails. I have explained before that the probability of a SPECIFIC mutation is low, but that's not what you should be looking at -- you should be looking at the probability of ANY mutation, for the reason I have explained in the numbered points above.

In probability-speak:
- You are looking at: GIVEN that life has evolved, what is the probability that a wing (or wheel or specific type of fish etc etc) has evolved.
- You should be looking at: What is the probability that ANY mutation will occur in an infinitessimal time dt, and then integrate that probability over a geologically significant timescale.

It seems we have determined where exactly you've gone wrong -- you haven't grasped the basic fact of natural selection that what mutation is "beneficial" is SOLELY determined by the mutated sub-species ability to increase in population, and NOT by how "useful" we think it might be.

I admit, it is a tricky and somewhat unintuitive concept to grasp. But you merely have to look at how, for example, viruses develop resistance to antibiotics and antibodies to realise that it happens through unguided selective pressure.

EDIT: I know it's a tricky concept to grasp, because when I was at school, I found it difficult, and got a particular (and life changing) question wrong the GCSE mock exam.

 

[Shaihulud]

Wings, I argue also belong in the class of things that include wheels, that cannot result merely from evolution.

You harp on that, yet ignore every evidence presented with propabilistic argument that cannot be applied to rates of mutation or its outcome. Understand that evolution is not entirely random, there are factors that skew the genetic outcome in favour of survival of the species, features that are anachronistic are phased out, features that improve on the species are amplified. True mutation that emphasize on vestigial features may be rare, but if it was clearly a great evolutionary advantage, it will be amplified. Clearly flight has evolved several times in the past, insects, reptiles, birds. from this evidence we can see that it was clearly an advantage that several species have taken advantage of. Some dinosaurs, such as the archaeopteryx shows evidence that it was in the intermediate stage where more advance flying could develop. Flying squirrels may develop their skills into true flight in the future, if it was important enough to ensure survival.

Btw I do not see how the article says that there is no plausible ways that wings could hav evolved, they did show a couple of example.

 

[wit>trope]

Btw I do not see how the article says that there is no plausible ways that wings could hav evolved, they did show a couple of example.

It says it right here:

"But we really can't conceive of finding real evidence that will decide the plausibility of these hypotheses"

So according to the article YOM linked to there are no known plausible accounts of how wings could have evolved!

 

[Shaihulud]

Surly you can see that some of the hypothesis are likely even if they are not testable? I suppose in the field of archaeology there are no definite solutions, except the most propable one.

 

[wit>trope]

Again, YOU think they are USEFUL. Evolution does NOT "think" at all, it does NOT "decide" what is "useful"

My point was that if some animals were to possess wheels then natural selection would incredible FAVOR it and wheels would propagate in the gene pool. But wheels never evolved because there are some class of things that natural selection would favor, even incredibly favor, but which are not capable of spontaneously arising merely from the mechanism of natural selection. So you have to get out of the in-the-box thinking that just because something would be favored by natural selection that natural selection is capable of producing it.

If you're saying that natural selection wouldn't favor wheels if some animals somehow got wheels then I think you're wrong about that. If an animal had well-functioning wheels it could get away from predators faster than without them and so it'd be more likely to reproduce.

- You are looking at: GIVEN that life has evolved, what is the probability that a wing (or wheel or specific type of fish etc etc) has evolved.

Um no that's not what I'm looking at. You are lumping things together in a way that I haven't done. I'm looking at the probability of mutations falling under a certain class (a class whose definition I have in mind). Mutations which involve the evolving of fish of a certain color for example would NOT fall under this class.

- You should be looking at: What is the probability that ANY mutation will occur in an infinitessimal time dt, and then integrate that probability over a geologically significant timescale.

You don't need to do any of that. You can just examine the probability of a mutation over x generations. But I am not interested in the probability of any mutation. I am interested in the probability of there being mutations over x generations which fall under a certain class. More precisely or aptly I am interested in:

P(A\B) which by Bayes theorem is equal to P(B\A)P(A)/P(B)

where A is all life resulting from evolution and B is there existing features of some animals which features had they evolved would involve a series of mutations falling under a certain class (whose definition I have in mind and would include wings and wheels).

Bayes theorem:

http://en.wikipedia.org/wiki/Bayes_theorem
http://plato.stanford.edu/entries/bayes-theorem/

 

[wit>trope]

Surly you can see that some of the hypothesis are likely even if they are not testable?

I don't agree that any of these particular hypotheses is likely (nor does the author of the article btw say that any of them is likely; he doesn't even say that any of them is plausible), but I might agree that as a general matter a conjecture can be likely true even if it is not testable but then that would make it not science according to Mise's own definition:

"science ONLY deals with TESTABLE hypotheses"



Mise's definition not only leaves out evolution science but also leaves out mathematics! Mathematics includes many conjectures which are not testable. Maybe one day somehow some of them could be proved, but none of them can ever be tested. Example:

http://en.wikipedia.org/wiki/Goldbach's_conjecture

 

[Mise]

My point was that if some animals were to possess wheels then natural selection would incredible FAVOR it and wheels would propagate in the gene pool. But wheels never evolved because there are some class of things that natural selection would favor, even incredibly favor, but which are not capable of spontaneously arising merely from the mechanism of natural selection. So you have to get out of the in-the-box thinking that just because something would be favored by natural selection that natural selection is capable of producing it.

What are you talking about?? I don't see what this has to do with anything I said, anything you have said, or evolution in the general sense

If you're saying that natural selection wouldn't favor wheels if some animals somehow got wheels then I think you're wrong about that.

Again, when did I say that natural selection wouldn't favour wheels?

Um no that's not what I'm looking at. You are lumping things together in a way that I haven't done. I'm looking at the probability of mutations falling under a certain class (a class whose definition I have in mind). Mutations which involve the evolving of fish of a certain color for example would NOT fall under this class.

Yes that is what you are looking at: by defining a "class" at all, you are limiting yourself to those classes which you can conceive. There are other "classes" which you, being limited by human imagination, cannot conceive, and these are just as likely to occur as those you can conceive. Like I said - think of how many ways there are to go to the shop - now think of how many different variations can improve the ability of an animal to survive.

You don't need to do any of that. You can just examine the probability of a mutation over x generations. But I am not interested in the probability of any mutation.

Which is where you are going wrong.

I am interested in the probability of there being mutations over x generations which fall under a certain class. More precisely or aptly I am interested in:

P(A\B) which by Bayes theorem is equal to P(B\A)P(A)/P(B)

where A is all life resulting from evolution and B is there existing features of some animals which features had they evolved would involve a series of mutations falling under a certain class (whose definition I have in mind and would include wings and wheels).

And why exactly are you interested in that???

Regarding your pathetic demonstration of twisting my words given in good faith, they call it a CONJECTURE, because it is not a scientific THEORY.

A THEORY must be TESTABLE.

How many times must I say this? Please, get it through to your head and stop twisting my words, it's really pathetic, and quite irritating...

And thank you for ignoring the other part of my post... Why do I take the time to post at all, when you completely ignore them

He was talking about wings. EDIT: I should say something here that he was talking about the answer to the question, "Why did wings improve the ability of the sub-species to survive." Evolution, OTOH, doesn't need to know why, all it needs to know is that it improved the ability of the sub-species to survive. Evolution doesn't concern itself with the "why" -- the scientist is speculating on something related to but not formally part of the theory of evolution. [/EDIT]

Evolution, OTOH, is testable. For example, an evolutionary sequence goes:
a, b, c, d, e, f, ?, h, i.
Evolution "predicts" that the "?" is a "g" -- we can "test" that by looking at geological evidence in the form of fossils and bones -- if we find a "g", the prediction of evolution is true, if not, it's back to the drawing board. Such predicted missing links in the evolutionary chain have been tested and proven in the past. This is what we talk about when we consider a "provable" evolution.

I should add to this that we can show that a mutation enables a species to survive simply by looking at which sub-species have survived and which have become extinct (i.e. that the "a" has become extinct in favour of the "b" and so on).

Bottom line:
Do you or do you not admit that for a theory to be scientific it must be testable, and that the words of Yom's link in no way demonstrates that evolution is not a scientific theory?

Honestly, it is really quite offensive that you ignore parts of my posts and twist the other parts when it suits you.