How does natural selection determine which mutations remain and which do not?

[tas8831]

and not every chemoreceptor is able to detect an odor molecule too:

"that can activate a nearby nerve fiber if the chemosensor is a specialized sensory receptor cell, such as the taste receptor in a taste bud[2][3] or in an internal peripheral chemoreceptor such as the carotid body"

Chemoreceptor - Wikipedia

as i said: an olfactory receptor is a special kind of receptor and not every receptor is able to bind an odor molecule.

Forest and trees comes to mind.

At least you are no longer relying on failed analogies presented as evidence.

 

[tas8831]

and yet: we will need a new mutation in moving to olfactory receptor from non olfactory receptor.

Amazing.

How were all the different chemoreceptors Created, and what is your evidence?

 

[xianghua]

New mutations happen all the time, so again, relevance?

again: if the first mutation is neutral (and i showed here why it need to be neutral), then we need to calculate what is the chance to get about 3 different parts by a nautral evolution. and the chance is very low.

 

[PsychoSarah]

again: if the first mutation is neutral (and i showed here why it need to be neutral)

You sincerely don't demonstrate that. A mutation that results in a new structure that has no function isn't neutral. Neutral mutations, by definition, have no recognizable impact on physiology.

, then we need to calculate what is the chance to get about 3 different parts by a nautral evolution. and the chance is very low.

-_- the first mutation being neutral would be irrelevant; chances are it wouldn't even alter the impact of the next benign or detrimental mutation on that gene very much. That is, unless you confuse the generation of a useless structure with neutrality.

Not that you have once demonstrated that the first steps in the development of any structure have to involve developments that change physiology in ways that lead to absolutely no benefit.

 

[tas8831]

again: if the first mutation is neutral (and i showed here why it need to be neutral), then we need to calculate what is the chance to get about 3 different parts by a nautral evolution. and the chance is very low.

Show your work.

Also show that evolution operates in the manner in which you seem to be demanding it should.

 

[tas8831]

Amazing.

How were all the different chemoreceptors Created, and what is your evidence?

Hello?

What are the odds that a deity would create a chemoreceptor, and then had to wait around for 3 more miracles to create the olfactory receptor? very low. Very, very low odds.

 

[xianghua]

You sincerely don't demonstrate that. A mutation that results in a new structure that has no function isn't neutral. Neutral mutations, by definition, have no recognizable impact on physiology.

i find no problem to consider it as a neutral mutation since it have no biological rule. so for the sake of discussion lets consider any such mutation as neutral.

 

[PsychoSarah]

i find no problem to consider it as a neutral mutation since it have no biological rule.

Is it just me, or has your grammar and sentence structure gotten significantly worse? I'm actually starting to have trouble reading your posts, and that has not always been the case.

My guess is that you consider it a neutral mutation because whatever structure added has no function. That's not the same thing as it doing nothing; it takes up space and resources. The type of mutation you are describing would be mildly detrimental, not neutral.

Also, you STILL have not demonstrated that the situation you are talking about has to happen for new structures to form. There is no demonstrable reason that a structure couldn't have various functions as it changes from start to "finish" (air quotes because evolution is a continuous process that never stops).

so for the sake of discussion lets consider any such mutation as neutral.

No, you don't get to redefine these established terms for the sake of discussion. I don't even understand why you want to, considering that the mutations you are describing would be considered mildly detrimental. Wouldn't it be more in your favor to argue that detrimental mutations would be a necessary part of the development of a benign structure, and thus natural selection couldn't possibly select for it? Why am I a better creationist than you, come on, a challenge would be nice.

 

[xianghua]

Also, you STILL have not demonstrated that the situation you are talking about has to happen for new structures to form. There is no demonstrable reason that a structure couldn't have various functions as it changes from start to "finish" (air quotes because evolution is a continuous process that never stops).

but we already seen that an olfactory receptor dont have any function by itself. so if we will consider it as step 1 (out of 3), then the first mutation (olfactory receptor) will be non functional.

 

[FrumiousBandersnatch]

Xianhua, if you're really curious about how specialized cells such as olfactory cells could have evolved, spend a little time looking at the evolution of multicellular organisms and how independently living cells can form colonies where groups of cells specialize to perform different roles - there are plenty of examples of contemporary creatures that form or are cooperative colonies, from bacteria, algae, and fungi, to sponges and jellyfish, and so-on (bear in mind that the earliest colony organisms would have been rather less refined).

Here's a theoretical paper on the evolution of functional specialization for your enjoyment

 

[FrumiousBandersnatch]

but we already seen that an olfactory receptor dont have any function by itself. so if we will consider it as step 1 (out of 3), then the first mutation (olfactory receptor) will be non functional.

Consider a simple organism that uses surface cells with flagellae for orientation and locomotion. Suppose now that a surface cell becomes sensitized to some class of external chemicals by a mutation, and this sensitivity results in a cellular signal (biochemical transmitter, membrane depolarization, or whatever) being triggered when this class of chemicals is encountered. If this signal influences the surrounding flagellae, either to reduce or increase their motility, the organism will correspondingly move towards or away from, respectively, the sensitizing chemical signal.

If movement towards that chemical signal is advantageous, the mutation is likely to persist in the offspring of the organism. If disadvantageous, it is not likely to persist - and so a primitive olfactory 'organ' begins to evolve.

 

[PsychoSarah]

but we already seen that an olfactory receptor dont have any function by itself.

We know that this structure is CURRENTLY dependent upon others to function, but you have yet to demonstrate that it isn't derived from a structure that functioned independently, or that it didn't develop until after the basic accessory structures it utilizes already existed.

so if we will consider it as step 1 (out of 3),

If we did that, we'd already be making a huge mistake.

then the first mutation (olfactory receptor) will be non functional.

You are ASSUMING that it started out this way, which is hugely erroneous. That's like saying that the first limb was a complete human arm missing an elbow.

 

[tas8831]

but we already seen that an olfactory receptor dont have any function by itself.

You mean a chemoreceptor has no function unless it is an olfactory receptor?

so if we will consider it as step 1 (out of 3), then the first mutation (olfactory receptor) will be non functional.

So you are saying that the step-by-step Design of an olfactory receptor is false?

 

[xianghua]

Suppose now that a surface cell becomes sensitized to some class of external chemicals by a mutation, and this sensitivity results in a cellular signal (biochemical transmitter, membrane depolarization, or whatever) being triggered when this class of chemicals is encountered.

so you just replace one complex system by another one with even more components: flagellum, receptor, processing system, a signal transition system etc. even so i dont see how by adding a new olfactory receptor to a motion system we will end up with an olfactory system. its like moving from a dvd into a video camera.

 

[xianghua]

We know that this structure is CURRENTLY dependent upon others to function, but you have yet to demonstrate that it isn't derived from a structure that functioned independently, or that it didn't develop until after the basic accessory structures it utilizes already existed.

again: we can compare it with a car for instance. if you agree that a car cant evolve stepwise then why we cant conclude the same for living systems?

 

[Speedwell]

again: we can compare it with a car for instance. if you agree that a car cant evolve stepwise then why we cant conclude the same for living systems?

Because cars only "evolve" in a metaphorical sense, not through the random variation of heritable traits followed by natural selection.

 

[xianghua]

Because cars only "evolve" in a metaphorical sense, not through the random variation of heritable traits followed by natural selection.

so lets say that we will have a self replicating matter. do you think that it can evolve stepwise into a car?

 

[xianghua]

You mean a chemoreceptor has no function unless it is an olfactory receptor?

roughly.

 

[Speedwell]

so lets say that we will have a self replicating matter. do you think that it can evolve stepwise into a car?

What is design and how do you detect it in an object?

 

[tas8831]

roughly.

Explain how you know this.

Are you a scientist?