Proposal: Human Brain Evolution

[mark kennedy]

I do this from time to time and evolutionists run for the trees but here goes. I am proposing a debate with an evolutionist who wants to defend the concept that the evolution of the human brain from that of apes has a molecular basis. Willing to discuss the specifics and the parameters of course, hoping for an honest open discussion.

Grace and peace,
Mark

 

[Ophiolite]

I do this from time to time and evolutionists run for the trees but here goes. I am proposing a debate with an evolutionist who wants to defend the concept that the evolution of the human brain from that of apes has a molecular basis. Willing to discuss the specifics and the parameters of course, hoping for an honest open discussion.

I am not well versed in molecular biology, so I may not be an appropriate individual to engage you on this. I am, however, seeking clarification of what you mean by brain evolution having a molecular basis. It seems as if you wish to suggest that structure and nature of the brain are not the product of molecular processes initiated by DNA. Since that is an apparently nonsensical position, I suspect you mean something else, but am at a loss to see what it may be. Would you explain?

 

[mark kennedy]

I am not well versed in molecular biology, so I may not be an appropriate individual to engage you on this. I am, however, seeking clarification of what you mean by brain evolution having a molecular basis. It seems as if you wish to suggest that structure and nature of the brain are not the product of molecular processes initiated by DNA. Since that is an apparently nonsensical position, I suspect you mean something else, but am at a loss to see what it may be. Would you explain?

Gladly, in order for a human brain to have emerged from that of apes it would require a molecular basis. There is no such thing. We know from genetics and medical science what the effects of mutations on brain related genes are and they are invariably deleterious. The molecular basis for the evolution of the human brain from that of apes, that is the challenge. I could offer you a reading list if you interested.

 

[Ophiolite]

Gladly, in order for a human brain to have emerged from that of apes it would require a molecular basis. There is no such thing. We know from genetics and medical science what the effects of mutations on brain related genes are and they are invariably deleterious. The molecular basis for the evolution of the human brain from that of apes, that is the challenge. I could offer you a reading list if you interested.

Thank you for your reply. I am still somewhat unclear of your precise intent, as your usage of terminology does not appear to be standard. However, you are very clear in this statement:

We know from genetics and medical science what the effects of mutations on brain related genes are and they are invariably deleterious.

Assuming your reading list has citations from reputable peer reviewed journals I would be interested to see the three you consider to be most important in supporting that assertion. I shall likely have further questions, or my first observations, once I have digested those.

 

[mark kennedy]

Thank you for your reply. I am still somewhat unclear of your precise intent, as your usage of terminology does not appear to be standard. However, you are very clear in this statement:

We know from genetics and medical science what the effects of mutations on brain related genes are and they are invariably deleterious.

Assuming your reading list has citations from reputable peer reviewed journals I would be interested to see the three you consider to be most important in supporting that assertion. I shall likely have further questions, or my first observations, once I have digested those.

There is a long list:

Genetic Brain Disorders

Perhaps a simple place to start is here:

One of the study's major surprises is the relatively large number of genes that have contributed to human brain evolution. “For a long time, people have debated about the genetic underpinning of human brain evolution,” said Lahn. “Is it a few mutations in a few genes, a lot of mutations in a few genes, or a lot of mutations in a lot of genes? The answer appears to be a lot of mutations in a lot of genes. We've done a rough calculation that the evolution of the human brain probably involves hundreds if not thousands of mutations in perhaps hundreds or thousands of genes — and even that is a conservative estimate.” (Human Brain Evolution Was a 'Special Event')
​

You wanted peer reviewed papers, specifically the three most important. Ok, no problem:

An RNA gene expressed during cortical development evolved rapidly in humans, Nature, 443: 167-172.
Genetics and the making of Homo sapiens Nature 422, 849-857. 24 April 2003.
Accelerated evolution of nervous system genes in the origin of Homo sapiens. Cell. 2004 Dec 29
​

A word of caution, the genetic basis is inextricably linked to fossilized skulls of supposed ancestors.

This will give you an idea of the comparative anatomy:

FIGURE 2. Comparative neuroanatomy of humans and chimpanzees. Genetics and the making of Homo sapiens Nature 422, 849-857. 24 April 2003.​

Grace and peace,
Mark

 

[Ophiolite]

This is an interim response, therefore do not feel obligated to make any reply. I have not yet studied the references you have provided. (Thank you for those.) However, you appear to have offered two things:
1. A list of brain disorders that are genetically controlled.
2. Examples of many mutations that would have been necessary to evolve the brain.

Neither of these even approaches a demonstration that mutations affecting the brain "are invariably deleterious". I know of no one who would claim that there are not many negative mutations. Anyone who makes that claim deserves to be roundly castigated, mocked and then ignored. However, listing some of those many negative mutations is not the same as demonstrating that only negative mutations have occurred.

At this early stage of our discussion I am rather disappointed if this represents the heart of your argument. I had hoped there might be something of substance to debate.

 

[Armoured]

in order for a human brain to have emerged from that of apes it would require a molecular basis.

Could you try to rephrase this? I can't even guess at what you mean by it.

 

[USincognito]

Could you try to rephrase this? I can't even guess at what you mean by it.

It's the same shtick he's been trotting out for 10 years. "There's no molecular basis for human brain evolution" and his reasoning is "human brains are three times the size of chimpanzee and HAR1 was conserved fro 310 million years".

He'll ignore or talk around anything else brought up on the subject.

 

[Papias]

At this early stage of our discussion I am rather disappointed if this represents the heart of your argument. I had hoped there might be something of substance to debate.

That's because is the same line of misinformation and distortions mark has been bringing up for nearly a decade. Each time, people who know the science of what he's talking about correct him, and his points are thoroughly refuted. After that, he resorts to his common lines about shooting fish in a barrel, chasing ghosts in the fog, and several others.

If you'd like a preview of what the entire debate will contain, simply click on any of these links to see the process described above as it played out time after time in the past - note that these go back to 2007:

http://www.christianforums.com/search/5024724/?q="Comparative+neuroanatomy+of+humans+and+chimpanzees"&o=relevance&c[user][0]=29337

In Christ-

-Papias

 

[Ophiolite]

@mark kennedy

So far I have read one of your recommended papers and will want to comment on that later, but I return to your statement that "We know from genetics and medical science what the effects of mutations on brain related genes are and they are invariably deleterious".

Before we can advance any further I need you to provide clear evidence that this is the case. A list of breakfast cereals is not proof that salads do not exist. A list of deleterious mutations is not proof that beneficial mutations do not exist. Please provide evidence to support your contention that "the effects of mutations on brain related genes are ....... invariably deleterious."

I continue to accept that you are serious about conducting a serious discussion on this subject. Perhaps you would be willing to amend the word invariably to read often, or some such equivalent. I would not consider such an amendment devalued your entire argument, but would feel it more accurately reflected what the literature on the topic would tell us. So, an amendment, or some hard evidence. The choice is entirely yours.

 

[46AND2]

So, an amendment, or some hard evidence. The choice is entirely yours.

Prediction:

"C: none of the above"

 

[mark kennedy]

This is an interim response, therefore do not feel obligated to make any reply. I have not yet studied the references you have provided. (Thank you for those.) However, you appear to have offered two things:
1. A list of brain disorders that are genetically controlled.
2. Examples of many mutations that would have been necessary to evolve the brain.

Neither of these even approaches a demonstration that mutations affecting the brain "are invariably deleterious". I know of no one who would claim that there are not many negative mutations. Anyone who makes that claim deserves to be roundly castigated, mocked and then ignored. However, listing some of those many negative mutations is not the same as demonstrating that only negative mutations have occurred.

At this early stage of our discussion I am rather disappointed if this represents the heart of your argument. I had hoped there might be something of substance to debate.

There are two things to discuss here, first the comparative anatomy of the human and chimpanzee brain, then the genetic differences that cause them. The human brain is about 2 to 3 times larger then a chimpanzee which means it would require an adaptive evolution:

Is it a few mutations in a few genes, a lot of mutations in a few genes, or a lot of mutations in a lot of genes? (Bruce Lahn)
​

The problem is that brain related genes are highly conserved and do not respond well to mutations.

The 118-bp HAR1 region showed the most dramatically accelerated change , with an estimated 18 substitutions in the human lineage since the human–chimpanzee ancestor, compared with the expected 0.27 substitutions on the basis of the slow rate of change in this region in other amniotes . Only two bases (out of 118) are changed between chimpanzee and chicken, indicating that the region was present and functional in our ancestor at least 310 million years (Myr) ago. No orthologue of HAR1 was detected in the frog (Xenopus tropicalis), any of the available fish genomes (zebrafish, Takifugu and Tetraodon), or in any invertebrate lineage, indicating that it originated no more than about 400Myr ago (An RNA gene expressed during cortical development evolved rapidly in humans, Nature 2006)
​

Now that indicates that the gene originated no more then 400 years ago and was present and functional 300 million years ago. Then it allows only two substitutions until 2-5 million years when it gets 18. The fact is that brain related genes do not respond well to mutations, there is a long list of deleterious effects and virtual no beneficial effects from mutations in human brain related genes known to modern science.

There are some pretty good papers on the subject:

An RNA gene expressed during cortical development evolved rapidly in humans. Nature 2006
Accelerated Evolution of Nervous System Genes in the Origin of Homo sapiens, Cell 2004
Genetics and the making of Homo sapiens Nature 2003​

There is a whole genome sequence of the Gorilla genome out there if it seems relevant, as well as an assortment of hominid fossilized skulls. There is a large body of work surrounding the subject matter so narrowing things down to a few comparisons and specific genomic sequences might prove helpful.

Have a nice day
Mark

 

[Ophiolite]

There are two things to discuss here, first the comparative anatomy of the human and chimpanzee brain, then the genetic differences that cause them. The human brain is about 2 to 3 times larger then a chimpanzee which means it would require an adaptive evolution:

Is it a few mutations in a few genes, a lot of mutations in a few genes, or a lot of mutations in a lot of genes? (Bruce Lahn)
​

The problem is that brain related genes are highly conserved and do not respond well to mutations.

The 118-bp HAR1 region showed the most dramatically accelerated change , with an estimated 18 substitutions in the human lineage since the human–chimpanzee ancestor, compared with the expected 0.27 substitutions on the basis of the slow rate of change in this region in other amniotes . Only two bases (out of 118) are changed between chimpanzee and chicken, indicating that the region was present and functional in our ancestor at least 310 million years (Myr) ago. No orthologue of HAR1 was detected in the frog (Xenopus tropicalis), any of the available fish genomes (zebrafish, Takifugu and Tetraodon), or in any invertebrate lineage, indicating that it originated no more than about 400Myr ago (An RNA gene expressed during cortical development evolved rapidly in humans, Nature 2006)
​

Now that indicates that the gene originated no more then 400 years ago and was present and functional 300 million years ago. Then it allows only two substitutions until 2-5 million years when it gets 18. The fact is that brain related genes do not respond well to mutations, there is a long list of deleterious effects and virtual no beneficial effects from mutations in human brain related genes known to modern science.

There are some pretty good papers on the subject:

An RNA gene expressed during cortical development evolved rapidly in humans. Nature 2006
Accelerated Evolution of Nervous System Genes in the Origin of Homo sapiens, Cell 2004
Genetics and the making of Homo sapiens Nature 2003​

There is a whole genome sequence of the Gorilla genome out there if it seems relevant, as well as an assortment of hominid fossilized skulls. There is a large body of work surrounding the subject matter so narrowing things down to a few comparisons and specific genomic sequences might prove helpful.

Have a nice day
Mark

Thank you for the courtesy of your reply. I would now appreciate it if you would address my request. I repeat it here for your convenience.

Please provide evidence to support your contention that "the effects of mutations on brain related genes are ....... invariably deleterious."

 

[mark kennedy]

Thank you for the courtesy of your reply. I would now appreciate it if you would address my request. I repeat it here for your convenience.

Please provide evidence to support your contention that "the effects of mutations on brain related genes are ....... invariably deleterious."

You can't prove a negative, I don't need proof for something that doesn't happen. Alzheimer's, Schizophrenia, Brain Cancer. Hundreds, if not thousands of mutations in hundreds, if not thousands of genes is not a formula for adaptive evolution. It's a formula for extinction.

Now if you don't buy the fact that they are invariably deleterious, show me an exception.

Have a nice day
Mark

 

[Ophiolite]

You can't prove a negative, I don't need proof for something that doesn't happen. Alzheimer's, Schizophrenia, Brain Cancer. Hundreds, if not thousands of mutations in hundreds, if not thousands of genes is not a formula for adaptive evolution. It's a formula for extinction.

Now if you don't buy the fact that they are invariably deleterious, show me an exception.

Have a nice day
Mark

I shall certainly do so, though not immediately. Work may consume much of my time for the next few days and it is Wimbledon.

Do you not think it would have been more accurate and therefore less misleading to say that, in your opinion, "there was no evidence that mutations relevant to the brain were invariably deleterious"? I agree you cannot prove a negative, but if what you claim to be the case is true then there should be megastudies out there that report of the hundreds, if not thousands of mutations known to have occurred none of them were deleterious. You can't come up with even a single study showing that?

 

[mark kennedy]

I shall certainly do so, though not immediately. Work may consume much of my time for the next few days and it is Wimbledon.

Of course, there is no need to rush this. I think the challenge is going to be boiling it down. That will take some time, I'm well aware we both have other more pressing matters.

Do you not think it would have been more accurate and therefore less misleading to say that, in your opinion, "there was no evidence that mutations relevant to the brain were invariably deleterious"? I agree you cannot prove a negative, but if what you claim to be the case is true then there should be megastudies out there that report of the hundreds, if not thousands of mutations known to have occurred none of them were deleterious. You can't come up with even a single study showing that?

That was a general inference based on years of search through the scientific literature. What you will find when gleaning through the scientific literature are comparative studies that identify what would have had to happen. For instance, Bruce Lahn has done extensive research in this area and I have found him to be an invaluable source:

Human evolution is characterized by a rapid increase in brain size and complexity. Decades of research have made important strides in identifying anatomical and physiological substrates underlying the unique features of the human brain. (Genetic basis of human brain evolution NCBI Trends Neurosci. Dec 2008)
​

I don't know what your experience in college was but I learned to become an excellent skimmer. I say that because if you were to follow the link in the citation you would find a list of related articles. No one attempts to do something like you are suggesting so I doubt seriously you are going to find a genome wide analysis and comparison of all mutations effecting the human brain. You have to understand, this kind of comparison has only been possible since 2001, that's not a lot of time for the kind of research you are suggesting.

Lahn's team sequenced an impressive number of human DNA samples to look for polymorphisms: 90 ethnically diverse individuals in both whole gene regions, later extending to more than 1000 individuals for more restricted haplotyping. (Evolutionary Genetics: Is brain evolution still continuing in modern humans? European Journal of Human Genetics 2006)
​

That's what I mean about Lahn, he has done this on the largest scale I'm aware of. The review of Lahn's work linked above is a commentary, which has the advantage of being more comprehensive then a peer reviewed scientific paper. It can help you get a feel for how the research is conducted, presented and reviewed. With that in mind, when you do manage to wade through the dense scientific literature you have a better over all view of what's being discussed and the terminology being used.

Enjoy Wimbledon, will you be competing this year? Just kidding, take your time on this, trust me on that. It's worth it in the long run and this kind of study just goes on forever.

Grace and peace,
Mark

 

[Loudmouth]

Gladly, in order for a human brain to have emerged from that of apes it would require a molecular basis. There is no such thing.

There is such a thing, and it is the mutations that separate chimps and humans. Mark has been shown this on multiple occasions, yet he can't seem to figure it out.

He claims that any changes to any of these brain related genes is deleterious, yet here are humans with changes in those very genes and they benefit from them. These are the facts that Mark avoids every single time.

 

[Loudmouth]

You can't prove a negative, I don't need proof for something that doesn't happen. Alzheimer's, Schizophrenia, Brain Cancer. Hundreds, if not thousands of mutations in hundreds, if not thousands of genes is not a formula for adaptive evolution. It's a formula for extinction.

Then why haven't humans gone extinct when they have mutations in brain related genes as compared to chimps?

 

[mark kennedy]

There is such a thing, and it is the mutations that separate chimps and humans. Mark has been shown this on multiple occasions, yet he can't seem to figure it out.

Talking about me in the third person, begging the question of proof yet again. At least you are consistent.

He claims that any changes to any of these brain related genes is deleterious, yet here are humans with changes in those very genes and they benefit from them. These are the facts that Mark avoids every single time.

Because that's what the reading of the requisite scientific literature will tell you. Mutations in brain related genes when they have an effect produce disease, disorder and death. LM has been shown this many times and continues to ignore this obvious and unavoidable fact concerning these highly conserved genes involved in the most vital organ in human anatomy.

Then why haven't humans gone extinct when they have mutations in brain related genes as compared to chimps?

Because the differences are due to the fact of independent creation and lineage. The differences are only called single base substitutions, indels and chromosome rearrangements because that is the presumed cause.

I can remember the time when there were a dozen trollers in every thread. The culture wars are over dude, God didn't go anywhere.

Have a nice day
Mark

 

[Loudmouth]

Talking about me in the third person, begging the question of proof yet again. At least you are consistent.

I don't have proof that there are 40 million differences between the chimp and human genomes?

I don't have proof that the sequence of brain related genes differs between chimps and humans?

Mutations in brain related genes when they have an effect produce disease, disorder and death.

Then why do you think the human and chimp brains are different sizes and different shapes? What is the cause of those physical differences if it is not the differences seen between their genomes?

Because the differences are due to the fact of independent creation and lineage.

Hold on a second. You are saying that if the natural process of mutation causes a specific mutation, then it is deleterious. However, if a deity produces that very same mutation then it isn't deleterious? How does that work?

The differences are only called single base substitutions, indels and chromosome rearrangements because that is the presumed cause.

No. Those are the observed differences. Whether a deity produced the difference or if natural processes produced the difference, they are still substitutions, indels, and recombinations.