Random mutations cannot explain evolution of humans

[sol invictus]

I hope you agree that if the vast majority of this huge number of synaptic connections were built up randomly, a normal human behaviour could not emerge. On the one hand we a relevant genetic information of 10^7 or 10^8 byte for the total ontogenetic development, and on the other hand only in the brain an architecture involving 10^15 synaptic connections. This results in less than 10^-7 or 10^-8 byte genetic information per synapse.

So what?

I can write a few-line computer program that will generate an arbitrarily large amount of non-random data. Then I could compute the number of bytes of code per byte of output, and it would be an even smaller number (but equally meaningless).

 

[Reality Check]

A further example of the missing genetic information (quote from Wikipedia):

"The human brain has a huge number of synapses. Each of the 10^11 (one hundred billion) neurons has on average 7,000 synaptic connections to other neurons. It has been estimated that the brain of a three-year-old child has about 10^15 synapses (1 quadrillion). This number declines with age, stabilizing by adulthood."​

I hope you agree that if the vast majority of this huge number of synaptic connections were built up randomly, a normal human behaviour could not emerge. On the one hand we a relevant genetic information of 10^7 or 10^8 byte for the total ontogenetic development, and on the other hand only in the brain an architecture involving 10^15 synaptic connections. This results in less than 10^-7 or 10^-8 byte genetic information per synapse.

So whereas the genetic information of a human only constitutes a small fraction of the storage capacity of a DVD disc of 4.7 Gigabyte, in order to store all the synaptic connections of a three-year-old child, around a million DVD discs are needed.

Congratulations Wolfgang - you have just proved that learning is impossible since all of the synapse connections in the brain are hard-coded in DNA !
As any biologist can tell you, neural development starts from a mostly random network of synaptic connections. Connections are then reinforced by learning.

 

[zosima]

Congratulations Wolfgang - you have just proved that learning is impossible since all of the synapse connections in the brain are hard-coded in DNA !
As any biologist can tell you, neural development starts from a mostly random network of synaptic connections. Connections are then reinforced by learning.

While competition within a random network of synapses is an important part of the developmental process, I just thought I'd note, completely tangentially, that the importance of new synaptic growth in adults is often overstated. As I understand it, most adult learning is actually just modification in the strength of synapses that were formed during childhood(or after traumatic brain injury).

But wrt this thread, I agree with you, reality. Wogoga's argument is ludicrous.

 

[Dancing David]

I hope you agree that if the vast majority of this huge number of synaptic connections were built up randomly, a normal human behaviour could not emerge. On the one hand we a relevant genetic information of 10^7 or 10^8 byte for the total ontogenetic development, and on the other hand only in the brain an architecture involving 10^15 synaptic connections. This results in less than 10^-7 or 10^-8 byte genetic information per synapse.

Oh man!

You really don't have a clue do you!

There is no architecheture to the growth of individual neurons, the architecture is a gross feature of scale. The arrangement of neuron is not like the paths on a silicon chip.

Um here is the deal, the way that neurons work is not predesigned like computer architechture, it is a conditioned thing that happens over time, first there is growth and exposure and then there is attenuation and potentiation. There is no predesigned soft ware package. It is [plastic, fluid and based upon exposure, development and then conditioning.

You are so wrong, you are not even close to being in the ball park. In fact you aren't even in the right town.

 

[wogoga]

...

1. There are multiple mechanisms by which variation between individuals may occur in a population, that is all natural selection needs.​

However, all these mechanisms leading to variation represent changes and therefore are considered mutations. Whereas variation is a property of a population or species at a given point in time, mutation is a change over time in individuals. The concept mutation normally covers all such changes.

If you start with one bacterium in a culture solution, we have (in the normal case) no variation. Replication cycles then lead to variation. By the way, pandualist evolution leads to this prediction: If the original bacterium has an artificially induced silent mutation in a given gene, then mutations from the artificial form to the wild form are substantially higher than other mutations. See also

2. I showed you a mathematical demonstration, albeit simplified, where it is shown how natural selection might increase a trait in a population.​

I'm sorry, what you have shown seems to me not a mathematical demonstration but a simple obfuscation by bluffing. Please present the argument in a reasonable way or provide a link with a reasonable presentation.

3. You have not demonstrated in the least why genetic miscopies would always be detrimental.​

I said that "the probability of detrimental effects is substantially higher than of useful effects". Yet to demonstrate the simplest and most obvious is sometimes the most difficult.

Think about randomly changing a few bits or bytes of a computer program. Think about random changes in a production process. Think about replacing, doubling, removing randomly characters, words and sentences in a text. Think about the easiness to destroy the function of proteins by artificially induced mutations and the difficulty to increase fitness of proteins by such mutations. Think about the easiness to induce by artificial mutations defects (e.g. blindness in fruit flies) and the difficulty to induce positive effects.

Some mutations are essentially switches from one known allele to another known allele, or from one known strain (e.g. normal bacterial strain) to another known strain (e.g. resistant).

4. You show mistaken logic by saying that since there are other mechanisms through which variation can occur, mutations can not lead to variation that natural selection can act upon.​

My logic seems confused to you only because of your strange distinction between changes called mutations and changes not called mutations. The normal interpretation of your statement

"You don't need mutations, variation in the expression of traits is sufficient!"​

in the context of this discussion is equivalent to

No further genetic changes were needed in the evolution of humans from proto-chimp/humans, the already existing variation in the proto-chimp/human population was sufficient.​

Cheers, Wolfgang

 

[Mashuna]

I said that "the probability of detrimental effects is substantially higher than of useful effects". Yet to demonstrate the simplest and most obvious is sometimes the most difficult.

Think about randomly changing a few bits or bytes of a computer program. Think about random changes in a production process. Think about replacing, doubling, removing randomly characters, words and sentences in a text. Think about the easiness to destroy the function of proteins by artificially induced mutations and the difficulty to increase fitness of proteins by such mutations. Think about the easiness to induce by artificial mutations defects (e.g. blindness in fruit flies) and the difficulty to induce positive effects.


Cheers, Wolfgang

If only there were some method in evolution for weeding out these detrimental effects. Some natural method for the selection of positive traits.

I wouldn't know what to call it, but I'm sure it would be useful.

 

[Dr Adequate]

A further example of the missing genetic information (quote from Wikipedia):

"The human brain has a huge number of synapses. Each of the 10^11 (one hundred billion) neurons has on average 7,000 synaptic connections to other neurons. It has been estimated that the brain of a three-year-old child has about 10^15 synapses (1 quadrillion). This number declines with age, stabilizing by adulthood."​

I hope you agree that if the vast majority of this huge number of synaptic connections were built up randomly, a normal human behaviour could not emerge. On the one hand we a relevant genetic information of 10^7 or 10^8 byte for the total ontogenetic development, and on the other hand only in the brain an architecture involving 10^15 synaptic connections. This results in less than 10^-7 or 10^-8 byte genetic information per synapse.

No. Each synapse contains all the genetic information.

Your method of taking averages here is like saying "The human body contains ten trillion cells, and the human population is six billion, so that's less than two thousand cells per person. So how come humans are so big?"

So whereas the genetic information of a human only constitutes a small fraction of the storage capacity of a DVD disc of 4.7 Gigabyte, in order to store all the synaptic connections of a three-year-old child, around a million DVD discs are needed.

Why yes. And I could specify the Mandlebrot set in a single line of mathematics, and yet it is infinitely complex.

My statement is correct, at least according to my interpretation. If DNA corresponding to 1000 bytes is used to code for 10 proteins, then the (non-redundant) genetic information (coding for independent degrees of freedom) reduces to 100 bytes per protein.

Either you're making the same silly mistake about averages, or you are mixing up alternatively spliced genes with operons.

 

[Dr Adequate]

My statement is correct, at least according to my interpretation. If DNA corresponding to 1000 bytes is used to code for 10 proteins, then the (non-redundant) genetic information (coding for independent degrees of freedom) reduces to 100 bytes per protein.

Look, let me explain alternative gene splicing to you.

It's like a form letter, where the person sending it out deletes what's inappropriate (usually, nowadays, by ticking the appropriate boxes on a computer). Something like this:

Dear (Sir/Madam), we note with (regret/contempt/rage) that your payments are (three/six/nine/twelve) months overdue, and if you do not remit immediately we shall (write you another letter/repossess your cat/send Big Eddie to break your thumbs).

Now, this requires 244 characters to specify 72 different letters. On average, therefore, that's less than 4 characters per letter.

And yet somehow the shortest possible letter one can compose by this method is 135 characters long.

 

[Nancarrow]

My statement is correct, at least according to my interpretation. If DNA corresponding to 1000 bytes is used to code for 10 proteins, then the (non-redundant) genetic information (coding for independent degrees of freedom) reduces to 100 bytes per protein.

Without looking through the rest of the thread, I really just want to examine this one piece here: shouldn't that be about 996 bits per protein, rather than 100? To select one out of say 10 proteins, you need to specify 3-and-a-bit bits, which leaves 996+a bit left over. Have I got that right?

 

[Dancing David]

1. There are multiple mechanisms by which variation between individuals may occur in a population, that is all natural selection needs.​

However, all these mechanisms leading to variation represent changes and therefore are considered mutations. Whereas variation is a property of a population or species at a given point in time, mutation is a change over time in individuals. The concept mutation normally covers all such changes.

Really, stop right here for a moment.

So the heigth of all indivduals in a population is the same? Really, or I have a mutation that makes me taller than my grandmother?

Are you sure about that?

Variation in the expression of traits.

Are you sure that my hair and eyes are the same as my parents?

(I am a brunette, with brown eyes) they are both 'dirty blonds' with hazel eyes, as are both my brother and sister.

Is that not variation in the expression of traits? Or do I have a mutation that makes my hair brown?

If you start with one bacterium in a culture solution, we have (in the normal case) no variation. Replication cycles then lead to variation. By the way, pandualist evolution leads to this prediction: If the original bacterium has an artificially induced silent mutation in a given gene, then mutations from the artificial form to the wild form are substantially higher than other mutations. See also

2. I showed you a mathematical demonstration, albeit simplified, where it is shown how natural selection might increase a trait in a population.​

I'm sorry, what you have shown seems to me not a mathematical demonstration but a simple obfuscation by bluffing. Please present the argument in a reasonable way or provide a link with a reasonable presentation.

Oh, I see in other words you don't have a rebuttal , so you resort to politics. If you don't understand algebra that is okay to say.

Okay here you go:

Pop. 1 starts at ten
Pop. 2 starts at ten,
we say that N the ratio of increase is 2, or that the population doubles every generation and that the extra birth B is 1 just to make it simple

So Pop. 1 goes like this 10,20,40,80,160,320,640,1280 as I said I simplified the notation in that the actual formula instead of being Population 1=N^S is actually Pop. 1 at gebneration S will be Pop.1 =10xN^S
Now the case for Pop 2 where we have N growth per generation and B extra birth is a little more complex

We start at 10 so first generation goes like this 10x2+10=31 since we have an extra birth for each member of the pupulation which reproduces
then we have 31x2+31=93
93x2+93=93x3=279
279x3=837

10,31,93,279,837,2511,7533,22599

Hmm, so in Pop. 1 we have
10,20,40,80,160,320,640,1280
and in Pop 2 we have
10,31,93,279,837,2511,7533,22599

so after eight generations we have a factor 20 in the growth of Pop. 2 over Pop.1.

Total of Pop.1 + Pop. 2=23839 with Pop.1 at 5% and Pop. 2 at 95%, even though they started out the same. and it works out even if you set the extra births at .1 , the extra child in generation 2 of Pop. 2 will have 128 children in generation 9, so generation 9 of Pop. 2 ,P2[9] will have at least 128 more than P1[9] and so on.

does that make more sense?

3. You have not demonstrated in the least why genetic miscopies would always be detrimental.​

I said that "the probability of detrimental effects is substantially higher than of useful effects". Yet to demonstrate the simplest and most obvious is sometimes the most difficult.

Think about randomly changing a few bits or bytes of a computer program.

Think about the fact that genes are not computer programs.

Think about random changes in a production process. Think about replacing, doubling, removing randomly characters, words and sentences in a text. Think about the easiness to destroy the function of proteins by artificially induced mutations and the difficulty to increase fitness of proteins by such mutations.

Now see, you haven't demonstrated it, just asserted it, if most of the genetic material does not directly code for anything, then why would a mutation even effect protein folding and production?

There is a crucial meaning in the fact that some changes will have no effect, some will have little effect and some will have major effects. So then you have to show which ones are neutral, which ones detrimental and which ones are beneficial.

Which you haven't.

Think about the easiness to induce by artificial mutations defects (e.g. blindness in fruit flies) and the difficulty to induce positive effects.

more assertion, think about antibiotic resistence in bacteria.

Some mutations are essentially switches from one known allele to another known allele, or from one known strain (e.g. normal bacterial strain) to another known strain (e.g. resistant).

that still donsn't do anything to demonstrate your statement.

4. You show mistaken logic by saying that since there are other mechanisms through which variation can occur, mutations can not lead to variation that natural selection can act upon.​

My logic seems confused to you only because of your strange distinction between changes called mutations and changes not called mutations. The normal interpretation of your statement

"You don't need mutations, variation in the expression of traits is sufficient!"​

in the context of this discussion is equivalent to

No further genetic changes were needed in the evolution of humans from proto-chimp/humans, the already existing variation in the proto-chimp/human population was sufficient.​

Cheers, Wolfgang

I see you still haven't an understanding of basic sentence construction much less logic.

I stated that variation in the expression of traits is sufficient for natural selection to act upon.


You do understand that human reproduction is not machine assembly, I hope?
the correct rephrasing of my statement might be:


No further mutation changes might be needed in the evolution of humans from proto-chimp/humans, the already existing variation in the expression of traits as subject to reproductive genetics in the proto-chimp/human population might be sufficient

 

[zosima]

Why yes. And I could specify the Mandlebrot set in a single line of mathematics, and yet it is infinitely complex.

Again completely tangentially, I find this to be an interesting example. When I read it , I thought: "Is it?" I don't really know. If you define complexity in terms of information entropy then its probably pretty simple and just deceptive in its appearance. But if we take the mandlebrot set to be simple, I think it makes our definition of complexity rather lacking....

Dr. Adequate:
If its not too distracting from the central point, how would you define complexity?

 

[Dr Adequate]

Again completely tangentially, I find this to be an interesting example. When I read it , I thought: "Is it?" I don't really know. If you define complexity in terms of information entropy then its probably pretty simple and just deceptive in its appearance. But if we take the mandlebrot set to be simple, I think it makes our definition of complexity rather lacking....

Dr. Adequate:
If its not too distracting from the central point, how would you define complexity?

In this instance? Intuitively. Obviously it's not very complex in terms of Kolmogorov complexity.

That's kind of the point, isn't it? My genes don't need to specify separately where each cell goes and what each one does: the complexity of the finished object is greater (in an intuitive sense) than the complexity of the shortest specification of it.

The analogy is:

Cell-by-cell description <-> Pixel-by-pixel description.

Genes <-> Equation specifying the Mandelbrot set.

 

[Dr Adequate]

Without looking through the rest of the thread, I really just want to examine this one piece here: shouldn't that be about 996 bits per protein, rather than 100? To select one out of say 10 proteins, you need to specify 3-and-a-bit bits, which leaves 996+a bit left over. Have I got that right?

No, not really.

See my "form letter" analogy in post #48, and the SW article on [swiki]splicing[/swiki].

 

[zosima]

In this instance? Intuitively. Obviously it's not very complex in terms of Kolmogorov complexity.

That's kind of the point, isn't it? My genes don't need to specify separately where each cell goes and what each one does: the complexity of the finished object is greater (in an intuitive sense) than the complexity of the shortest specification of it.

The analogy is:

Cell-by-cell description <-> Pixel-by-pixel description.

Genes <-> Equation specifying the Mandelbrot set.

I think its a good point. I totally agree that the apparent complexity and the complexity of specification are rarely similar. I often could care less about the central theme of a post and just kinda pick out posts that seem interesting. I guess I'd rather think about complexity than the silliness of this thread's topic.

Plus Wogoga won't answer my questions anyway, so what am I gonna do? I think he feels threatened that my spaghetti monster theory of demographic decline is almost as wooey as his soul juice theory of demographic decline.


Although I guess the more accurate analogy(although it lacks that umph) would be taking a mandelbrot plot and adding a little bit of random data to the value at any given step. Because the genome specifies an algorithm that operates in a very entropic environment, I don't think there is probably even a good mathematical way to compress the information in any human being.

 

[sol invictus]

In this instance? Intuitively. Obviously it's not very complex in terms of Kolmogorov complexity.

Couldn't we use a form of Shannon entropy?

Imagine starting with an approximation to the Mandelbrot fractal as generated by the first iteration of a computer program. The structure is there at large scales, but not at small. The next pass (like when you zoom in) will compute and add the structure at a smaller scale, the pass after that at a still smaller scale, etc.

With each pass, higher frequency information gets added. The power in the Fourier transform (of the whole thing, not just the part zoomed in on) increases and spreads to higher and higher frequencies. This is roughly like increasing the temperature, and the entropy will increase with each iteration.

Now, can we think of an iteration of the Mandelbrot generating algorithm as analogous to a generation? With each generation, more of the possible fit creatures differentiate from the original creature, "filling in" the small-scale structure. So this would be a measure of the complexity of the genome of all living creatures.

 

[Dr Adequate]

I hope?
the correct rephrasing of my statement might be:

No further mutation changes might be needed in the evolution of humans from proto-chimp/humans, the already existing variation in the expression of traits as subject to reproductive genetics in the proto-chimp/human population might be sufficient

That's about as unlikely as anything wogoga has claimed. More so, because we don't know the rules for his magic "psychons", whereas we do have quite a good understanding of genetics as understood by geneticists.

 

[Dr Adequate]

Now, can we think of an iteration of the Mandelbrot generating algorithm as analogous to a generation?

Well, if natural selection didn't act in any way ... so that the population grew exponentially ... then this analogy would still not provide any additional insight ... into what wogoga's talking about ... or anything else.

Moreover, it conflicts with the analogy we're already using where the equation corresponds to the genome and the pixel corresponds to the cell. In your version, the pixel corresponds to ... the organism? and the equation corresponds to ... what?

So no, I don't like the idea.

 

[zosima]

I don't know why we're talking about this. I don't know why I'm addressing this claim directly.

Wogoga:
Your claim is so obviously and trivially false I'd much rather take my time making ad hominems, but this has gone on too far.

First, you assume that there is only one way for a phenotype to be encoded by a genotype. This is not the case. Just as there are a huge number of different ways to write a computer program to perform a single task, there are tons of different genetic codes that can perform a given task. For example, I had a friend in college that did genetic engineering in plants. The way they did this was using a special bacteria that would basically just insert copies of a gene coding a protein whereever. Basically is was a gene shotgun. Nonetheless, this technique was effective.

Two, I'm not going to address your argument from complexity until you make it clear and coherent. Moreover, your example using the brain has been addressed by the others in this thread. It is false as well as inconsequential.

Now lets look at the numbers you provided initially...

Take the case of humans after their separation from chimps some million years ago. An upper limit to the number of individuals having been born since then is 10^16 (i.e. 10^9 newborns per year for 10^7 years).

Let us assume that three factors must be affected for an increase in fitness to emerge. So even if the probability of a beneficial mutation in a newborn were as high as 10^-5 for each factor, the probability that beneficial mutations occur for all three factors is 10^-15, i.e. extremely improbable.

So neo-Darwinism requires essentially this hypothesis:

Every evolutionary innovation can produced by a sequence of single-step mutations, each of which alone responsible for a relevant increase in fitness.​

So just to summarize.
10^9 newborns per year(I'll actually assume this is the individuals in a generation so your argument makes sense)
10^7 years
10^-5 probability for each relevant factor
3 factors.

For example, you cite, 10^-15 as the probability all 3 factors would occur in any single individual simultaneously. This is true.

But evolution doesn't work this way. As you say, "each of which alone (is) responsible for a relevant increase in fitness".

10^9*10^-5=10^4 We can expect one beneficial mutation to occur in as many as 10000 individuals per generation.

So after the first year of our thought experiment we have:
10000 individuals with mutation A
10000 individuals with mutation B
10000 individuals with mutation C
The probability that any one of these individuals has any two mutations is unlikely and the probability that any one individual has all three is infinitesimally small at this point. But, since each of these mutations increases fitness independently, we can assume that these individuals will do better than the others. Increasing their numbers in the next generation. So lets say the number of individuals inheriting each one of the 3 mutations doubles each generation.

Then in generation 2 we have 20000 individuals with A by inheritance, 10000 with A by mutation. The same for the others leading to 10000+20000= 30000 each of A,B,C in generation 2.

So at this point we can write the recurrence relation describing this growth:
P(t) = 2*P(t-1)-1(ignoring the factor of 10000)
The first few numbers are 1,3,7,15,31,63
Its easy to fit an analytic function to this sequence: P(t)=2^t-1
So P(17) *10000= 2^17-1*10000=131071*10^4 =~ 1.31*10^9 individuals with each mutation. Since the number of individuals with each mutation is greater than the number of individuals in any generation, we can infer all individuals will have all 3 mutations. (This might be thought of as an application of the pigeonhole principle.)

Two things are clear from the recurrence relation:
1. Wogoga's numbers are wildly generous
2. Because the recurrence relation is exponential even far more conservative numbers will not yield a significantly different result.


Obviously this is a simplified model, but this is the simplified correct analysis that grows out of Wogoga's initial suppositions. Other complexities won't change the fundamental fact that this demonstrates. Once an individual has a beneficial mutation it will spread throughout the population, so the argument from the probabilistic contingency(or independent joint probability) is clearly wrong. Can we please stop this silliness now?

p.s. The genetic shotgun bacteria is crazy neat, if I remember all the details. As I remember it, the wild type naturally uses special plasmids to insert genes into a plant that it is attacking. These inserted genes basically cause tumors in the plant that happen to be very tasty for the bacteria. When they use it for genetic engineering, the tumor plasmids are replaced with whatever gene they want to insert. Since the bacteria was savaging the plant anyway, it never evolved much specificity to insertion, so tons of copies of the gene end up in all sorts of places. Sometimes it does what they want, sometimes it does something different, sometimes the plants just die. But they run a few iterations and normally end up with a variant that does what they want, which they select for. Then they add another gene. Do this enough and you can insert all the enzymes in an entire pathway.

 

[richardm]

If only there were some method in evolution for weeding out these detrimental effects. Some natural method for the selection of positive traits.

I wouldn't know what to call it, but I'm sure it would be useful.

Hmm. I'm sure we could come up with something if we all put our heads together.

natural selection

Damn! This is why Dr Adequate keeps winning those language awards.

 

[sol invictus]

Well, if natural selection didn't act in any way ... so that the population grew exponentially ... then this analogy would still not provide any additional insight ... into what wogoga's talking about ... or anything else.

I've got no idea what wogoga's talking about, nor do I care. I'd rather have an interesting discussion.

Moreover, it conflicts with the analogy we're already using where the equation corresponds to the genome and the pixel corresponds to the cell. In your version, the pixel corresponds to ... the organism? and the equation corresponds to ... what?

It does conflict, yes - I didn't read your post carefully enough. Sorry about that.

In my version, the equation is natural selection plus mutations, and each iteration is a generation. Each pixel is the genome of a species. So this is a way of defining complexity of the metagenome (I don't know the right word) - the genomes of all species in existence at a given time.