Query on the God Delusion Book

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Folks,

I came across an extract Steve Grant on page 416 of the God Delusion by Dawkins See attached photo.

I dont quite understand what he is saying about us being waves. Could some-one give me a physical explanation what he meant?

I realise that the actual age of our body is not from the day we were born because the cells keep regenerating etc but I cannot extent the idea to the extract.

Thanks
 
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  • #2
Evo
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It's a really serious mistake on the part of Steve Grand. Although many of our cells die and are replaced it simply isn't true that there is 100% replacement of all cells in the human body.
 
  • #3
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So if my wife catches me at something I can always say that it wasn't really me?
 
  • #4
Ryan_m_b
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It's a really serious mistake on the part of Steve Grand. Although many of our cells die and are replaced it simply isn't true that there is 100% replacement of all cells in the human body.

Whilst true it is unlikely that any of the sub-cellular components of the cells are the same, all the biochemistry making up a cell is eventually recycled. I've never encountered a biological process that allowed something to be statically stored in the body.
 
  • #5
Evo
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Whilst true it is unlikely that any of the sub-cellular components of the cells are the same, all the biochemistry making up a cell is eventually recycled. I've never encountered a biological process that allowed something to be statically stored in the body.
To my knowledge, there are certain cells in the body that do not get replaced, such as the inner lens of the eye, some parts of the heart (recent research by Jonas Frisén shows that some cells of the heart do get replaced, however at a very slow rate). etc..

Since you are the expert on this, I'm moving to Biology. You most likely have the most up to date studies, and I'd love to have more recent information since this is a topic I am interested in.

My links

http://www.medicalnewstoday.com/articles/144917.php

Using this approach, Frisén and colleagues found that heart muscle cells renew gradually over our lifetime and the rate declines as we get older such that 1 per cent of our heart cells are replaced per year at age 25 and this falls to 0.45 per cent at age 75.

They also found that over a normal lifespan, fewer than 50 per cent of the heart's muscle cells are replaced.

and

http://www.ncbi.nlm.nih.gov/books/NBK28372/

Not all the populations of differentiated cells in the body are subject to cell turnover. Some cell types, having been generated in appropriate numbers in the embryo, are retained throughout adult life; they seem never to divide, and they cannot be replaced if they are lost.
 
  • #6
Ryan_m_b
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To my knowledge, there are certain cells in the body that do not get replaced, such as the inner lens of the eye, some parts of the heart (recent research by Jonas Frisén shows that some cells of the heart do get replaced, however at a very slow rate. etc..

Since you are the expert on this, I'm moving to Biology. You most likley have the most up to date studies, and I'd love to have more recent information since this is a topic I am interested in.

My links

http://www.medicalnewstoday.com/articles/144917.php

and

http://www.ncbi.nlm.nih.gov/books/NBK28372/

You are correct, there are indeed cells that last a lifetime, or at least cannot be renewed. However even if these cells themselves are not swapped they do regenerate their components. From the second reference you posted;

Most Permanent Cells Renew Their Parts
There are few cells as immutable as lens fibers. As a rule, even those cells that persist throughout life without dividing undergo renewal of their component parts. Thus, while they do not divide, heart muscle cells, auditory hair cells, and nerve cells are metabolically active and capable not only of synthesizing new RNA and protein, but also of altering their size and structure during adult life. Heart muscle cells, for example, replace the bulk of their protein molecules in the course of a week or two, and they will adjust the balance of protein synthesis and degradation so as to grow bigger if the load on the heart is increased - for example, by a sustained increase in blood pressure. Nerve cells also replace their protein molecules continuously; moreover, many nerve cells can regenerate axons and dendrites that have been cut off.

So over time these cells will have no constituent molecules that were there a set time before (even though at no point was the cell itself "gone"). Part of the problem with these http://en.wikipedia.org/wiki/Ship_of_Theseus" [Broken] thought experiments is that I am unaware of any study that has drawn together research to show exactly how long it takes the body to get to a state if having no atoms within it that were there X time ago. I'm not even sure how well this could be done, it's possible that some atoms by chance stay with us throughout life so it may be more appropriate to consider the idea of renewal as probabilistic rather than mechanical.
 
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  • #7
Evo
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So over time these cells will have no constituent molecules that were there a set time before (even though at no point was the cell itself "gone"). Part of the problem with these http://en.wikipedia.org/wiki/Ship_of_Theseus" [Broken] thought experiments is that I am unaware of any study that has drawn together research to show exactly how long it takes the body to get to a state if having no atoms within it that were there X time ago. I'm not even sure how well this could be done, it's possible that some atoms by chance stay with us throughout life so it may be more appropriate to consider the idea of renewal as probabilistic rather than mechanical.
I guess until we can run studies on humans with excessively long lifespans, we won't really know for certain. But based on what I've read, that even being in my early 50's I still have some original material.

Grand said:
Not a single atom that is in your body today was there when that event took place
Of course Grand was trying to make a point that physically we change, but wasn't 100% correct as far as our current knowledge goes, and what's the point? (yes, I hate philosophy)
 
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  • #8
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ok, so based on the replies given can we conclude that there is a probability that the sub components of a cell including atoms are eventually replaced?

Sorry I missed the previous thread. So the answer is theres a strong probability that some sub components of cells remain with us and hence we are nevered completely renewed. Thanks
 
  • #9
Ryan_m_b
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ok, so based on the replies given can we conclude that there is a probability that the sub components of a cell including atoms are eventually replaced?

Sorry I missed the previous thread. So the answer is theres a strong probability that some sub components of cells remain with us and hence we are nevered completely renewed. Thanks

I would say it is extremely unlikely that there would be some component that is never excreted. However the point is largely irrelevant, if all of the atoms in Alice's body when she dies were not there when she is born is there any real difference if Bob's body has a few carbon atoms locked in some proteins?
 
  • #10
Evo
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I would say it is extremely unlikely that there would be some component that is never excreted. However the point is largely irrelevant, if all of the atoms in Alice's body when she dies were not there when she is born is there any real difference if Bob's body has a few carbon atoms locked in some proteins?
Good answer!!
 
  • #11
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ok,

thanks folks!
 
  • #12
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I dont quite understand what he is saying about us being waves.

Say you have a glass tank and a single wave moves from left to right through a water medium in that tank. The atoms that started out being the wave on the left are not the same as the atoms that make the wave in the centre, or the atoms that are the wave on the right. Even though it is one and the same wave, it was made up of different pieces throughout it's lifespan (distance from left to right).

You are similar in some respects to the wave.
As you progress though life, your atoms, at varying stages and rates, may be replaced. What's important, what makes you, is the arrangement of those atoms at any given stage.

What the athur is trying to get across is that you aren't actually a "physical thing". What you consider to be you, the matter you're made of, is simply a medium through which you propogate.

At least that's my impression.
 
  • #13
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I see....
That is a tricly one to follow/imagine! Is this the generally accepted view on this for all living organisms?

Thanks
 
  • #14
I see....
That is a tricly one to follow/imagine! Is this the generally accepted view on this for all living organisms?

Thanks

Yes it is. No living system is static and components have to be replaced, added or removed in the course of metabolism, reproduction and repair.
 
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  • #15
Ryan_m_b
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I see....
That is a tricly one to follow/imagine! Is this the generally accepted view on this for all living organisms?

Thanks

I would hazard a guess that this is true of most things. For instance;

A river (never the same water nor the exact same path)
A nation (people are born, live, die)
Land (nutrients go in and out of the soil)
 
  • #16
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Hi, I had to pull off the shelf my hard copy of The God Delusion by Richard Dawkings. Has anyone besides myself read chapter 10 "A MUCH NEEDED GAP?" wherein the OP's attachment is located?
 
  • #17
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I would hazard a guess that this is true of most things.

The impression I often have is that it appears to be true for all things. The only difference between any two given systems in this seems to be the time which needs to elapse before the pattern becomes distinguishable to human observers.

By the way, RyanMB, I wanted to take the opportunity of having a biologist in arm's reach to ask a question which has been on my mind since viewing a video about an evolutionairy phenomenon known as "Ring Species".


What I've wanted to ask a professional biologist about this is whether or not it is possible that this "Ring Species" phenomenon could also occur within humanity over a sufficiently long passage of generations. I.e.: Would it actually be possible that the so-called "races" of the human species (generally subjectively designated along the lines of "white", "black" and "yellow") can genetically diverge to such an extent over time that men & women from these groups would no longer be able to interbreed with one another?

The reason I can't quite get this out of my mind is because, as my name might already suggest to a biologist, I am a person of somewhat mixed heritage myself. In the end, we humans are a part of the cycle that we observe in nature. Therefore I wanted to ask you: Is there a reason to assume that these same rules do not (or do not any longer) apply to us, or is indeed possible that humanity may be heading towards a status of Ring Species at one point in the future?
 
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  • #18
DavidSnider
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It's possible, but not likely, since there are no physical barriers to interracial breeding. Humans can hop across the globe in under a days time. Too much possibility for gene flow.
 
  • #19
Ryan_m_b
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By the way, RyanMB, I wanted to take the opportunity of having a biologist in arm's reach to ask a question which has been on my mind since viewing a video about an evolutionairy phenomenon known as "Ring Species".


Potholer54 is a great channel :smile:

What I've wanted to ask a professional biologist about this is whether or not it is possible that this "Ring Species" phenomenon could also occur within humanity over a sufficiently long passage of generations. I.e.: Would it actually be possible that the so-called "races" of the human species (generally subjectively designated along the lines of "white", "black" and "yellow") can genetically diverge to such an extent over time that men & women from these groups would no longer be able to interbreed with one another?

The reason I can't quite get this out of my mind is because, as my name might already suggest to a biologist, I am a person of somewhat mixed heritage myself. In the end, we humans are a part of the cycle that we observe in nature. Therefore I wanted to ask you: Is there a reason to assume that these same rules do not (or do not any longer) apply to us, or is indeed possible that humanity may be heading towards a status of Ring Species at one point in the future?

At one point there were http://en.wikipedia.org/wiki/Homo#Species", the level of interbreeding between them ranged between zero to little. It's only been in recent history (~10 kiloyears ago) that Homo sapiens became the only species left.

The reason ring species allow speciation is because we have http://en.wikipedia.org/wiki/Mutation" [Broken] between populations. The geographical separation allows the species to diverge.

As DavidSnider correctly points out this no longer applies to humans. Thanks to our technology and society there are no geographical barriers to interbreeding. If a population of humans were to be isolated then after a while they would speciate from the rest of us.
 
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  • #20
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At one point there were http://en.wikipedia.org/wiki/Homo#Species", the level of interbreeding between them ranged between zero to little. It's only been in recent history (~10 kiloyears ago) that Homo sapiens became the only species left.

That is astonishing. If I understand you correctly, then the so-called "Ring Species" phenomenon has in fact already occurred within humanity in the distant past, and all the people on Earth today are the descendants of the sole surviving variation of "human"?

The reason ring species allow speciation is because we have http://en.wikipedia.org/wiki/Mutation" [Broken] between populations. The geographical separation allows the species to diverge. As DavidSnider correctly points out this no longer applies to humans. Thanks to our technology and society there are no geographical barriers to interbreeding. If a population of humans were to be isolated then after a while they would speciate from the rest of us.

That seems to raise some questions of its own. In the case of us modern humans, the effect of geographical seperation seems at least to some extent to have become emulated by various means of birth control, cultural doctrines (and resulting peer pressure), policies & laws (more of a thing of the past now), etc. I am about 1/4th Native American from my mother's side (Standing Rock), and having been raised mainly by my grandparents in my youth I've come to know firsthand the impact of the blood quantum. (How strictly it is applied can vary a lot depending on the tribe in question, however.)

What fascinates me as a mildly mixed person is that in the last twenty years or so, the cultural and political climate arguably has never appeared to be more favorable towards interbreeding between humans. Yet, when I examined the recent Census data for the United States (2010 statistics), I found that under these conditions too interracial marriages remain something of an absolute minority. Assuming their current level of growth persists, it will take a very long time before they come to represent for example 25% of the total marriages each year.

In that scenario, about 75% of the population of the various ethnicities still remain in a state of little to no interbreeding as time progresses. The impression I get from this is that the only real obstacle speciation faces in occurring once more among humans is that we likely won't survive the next few millennia to begin with, considering the way we have come to treat our world. (Not to mention each other.)

This seems to be increasingly moving into the territory of anthropology and sociology, so I should probably stop hijacking this thread. Thank you for the responses, and especially for those Wikipedia links! They will likely result in hours of reading pleasure on my part.
 
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  • #21
Ryan_m_b
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That is astonishing. If I understand you correctly, then the so-called "Ring Species" phenomenon has in fact already occurred within humanity in the distant past, and all the people on Earth today are the descendants of the sole surviving variation of "human"?

I'm unaware of any ring species event in human history. Ring species specifically occur when a population speciates in a huge circle (e.g. around a mountain range). The Homo genus speciated just because different groups migrated to different areas.

As an example I've thrown together a sketch and attached it. In the left example we have the first species on the far right (the red star). A group of red stars migrate south west around the lake and diverge slightly, but not so much that they couldn't breed with the original population. From this group another smaller group migrates further around the lake and also diverges slightly. Eventually a population arrives from the north west to where the original population still lives but they have diverged so much they are a different species. This is a collection of ring species.

On the right hand example we have a bunch of islands in a sea. Every now and then a small group from a population migrate to a new island. Because of this they diverge and become different species. This is not a ring species.

The defining difference is that when you get ring species every group can mate with it's close neighbours but not with those further away, this is because the neighbours are close enough for interbreeding. I'm not sure if this ever happened to humans, as far as I know we took the route displayed on the right and just moved away from each other.

In that scenario, about 75% of the population of the various ethnicities still remain in a state of little to no interbreeding as time progresses.

Even so It would take a very long time for speciation to occur, if it did it would be an example of http://en.wikipedia.org/wiki/Sympatric_speciation" [Broken] because the two groups live in the same geographical area but don't breed.

The impression I get from this is that the only real obstacle speciation faces in occurring once more among humans is that we likely won't survive the next few millennia to begin with, considering the way we have come to treat our world. (Not to mention each other.)

This is another discussion in of itself but personally I find it highly unlikely that we as a species will die out any time soon. Current cultures and societies are another matter but that's besides the point. Enjoy reading and learning :smile:
 

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  • #22
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As an example I've thrown together a sketch and attached it.

My god. It's full of stars!

Seriously though, thank you for clarifying this for me.
 
  • #23
Ryan_m_b
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My god. It's full of stars!

Seriously though, thank you for clarifying this for me.

No problem :wink:
 
  • #24
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Richard Dawkin's does mention on page 99 of his book about 'the official Human Genome Project'. And, I must admit that I'm not so keen on using Wikipedia.

The National Human Genome Research Instituteon May 6, 2010 published "Complete Neanderthal Genome Sequenced - DNA Signatures Found in Present-Day Europeans and Asians, But Not In Africans":
Researchers have produced the first whole genome sequence of the 3 billion letters in the Neanderthal genome, and the initial analysis suggests that up to 2 percent of the DNA in the genome of present-day humans outside of Africa originated in Neanderthals or in Neanderthals' ancestors.

The international research team, which includes researchers from the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health, reports its findings in the May 7, 2010, issue of Science [1].

The current fossil record suggests that Neanderthals, or Homo neanderthalensis, diverged from the primate line that led to present-day humans, or Homo sapiens, some 400,000 years ago in Africa. Neanderthals migrated north into Eurasia, where they became a geographically isolated group that evolved independently from the line that became modern humans in Africa. They lived in Europe and western Asia, as far east as southern Siberia and as far south as the Middle East.

Approximately 30,000 years ago, Neanderthals disappeared. That makes them the most recent, extinct relative of modern humans, as both Neanderthals and humans share a common ancestor from about 800,000 years ago. Chimpanzees diverged from the same primate line some 5 million to 7 million years ago.

The researchers compared DNA samples from the bones of three female Neanderthals who lived some 40,000 years ago in Europe to samples from five present-day humans from China, France, Papua New Guinea, southern Africa and western Africa. This provided the first genome-wide look at the similarities and differences of the closest evolutionary relative to humans, and maybe even identifying, for the first time, genetic variations that gave rise to modern humans.

"This sequencing project is a technological tour de force," said NHGRI Director Eric D. Green, M.D., Ph.D. "You must appreciate that this international team has produced a draft sequence of a genome that existed 400 centuries ago. Their analysis shows the power of comparative genomics and brings new insights to our understanding of human evolution."

The Neanderthal DNA was removed from bones discovered at Vindija Cave in Croatia and prepared in the clean room facility of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, to prevent contamination with contemporary DNA. The Max Planck group is led by their Department of Evolutionary Genetics Director Svante Pääbo, Ph.D., a well-known pioneer in Neanderthal genome research. The team deposited the Neanderthal genome sequence in the publicly available NIH genetic sequence database GenBank.

To understand the genomic differences between present-day humans and Neanderthals, the researchers compared subtle differences in the Neanderthal genome to the genomes found in DNA from the five people, as well as to chimpanzee DNA. An analysis of the genetic variation showed that Neanderthal DNA is 99.7 percent identical to present-day human DNA, and 98.8 percent identical to chimpanzee DNA. Present-day human DNA is also 98.8 percent identical to chimpanzee.

Please read on . . .
http://www.genome.gov/27539119

1. Science is an internationally known peer-reviewed journal. Here's the link to the 'May 7, 2010, issue of Science' as mentioned above:

Vol. 328 no. 5979 pp. 710-722
DOI: 10.1126/science.1188021
•Research Article
A Draft Sequence of the Neandertal Genome
Richard E. Green1,*†‡, Johannes Krause1,†§, Adrian W. Briggs1,†§, Tomislav Maricic1,†§, Udo Stenzel1,†§, Martin Kircher1,†§, Nick Patterson2,†§, Heng Li2,†, Weiwei Zhai3,†||, Markus Hsi-Yang Fritz4,†, Nancy F. Hansen5,†, Eric Y. Durand3,†, Anna-Sapfo Malaspinas3,†, Jeffrey D. Jensen6,†, Tomas Marques-Bonet7,13,†, Can Alkan7,†, Kay Prüfer1,†, Matthias Meyer1,†, Hernán A. Burbano1,†, Jeffrey M. Good1,8,†, Rigo Schultz1, Ayinuer Aximu-Petri1, Anne Butthof1, Barbara Höber1, Barbara Höffner1, Madlen Siegemund1, Antje Weihmann1, Chad Nusbaum2, Eric S. Lander2, Carsten Russ2, Nathaniel Novod2, Jason Affourtit9, Michael Egholm9, Christine Verna21, Pavao Rudan10, Dejana Brajkovic11, Željko Kucan10, Ivan Gušic10, Vladimir B. Doronichev12, Liubov V. Golovanova12, Carles Lalueza-Fox13, Marco de la Rasilla14, Javier Fortea14,¶, Antonio Rosas15, Ralf W. Schmitz16,17, Philip L. F. Johnson18,†, Evan E. Eichler7,†, Daniel Falush19,†, Ewan Birney4,†, James C. Mullikin5,†, Montgomery Slatkin3,†, Rasmus Nielsen3,†, Janet Kelso1,†, Michael Lachmann1,†, David Reich2,20,*† and Svante Pääbo1,*

Abstract
Neandertals, the closest evolutionary relatives of present-day humans, lived in large parts of Europe and western Asia before disappearing 30,000 years ago. We present a draft sequence of the Neandertal genome composed of more than 4 billion nucleotides from three individuals. Comparisons of the Neandertal genome to the genomes of five present-day humans from different parts of the world identify a number of genomic regions that may have been affected by positive selection in ancestral modern humans, including genes involved in metabolism and in cognitive and skeletal development. We show that Neandertals shared more genetic variants with present-day humans in Eurasia than with present-day humans in sub-Saharan Africa, suggesting that gene flow from Neandertals into the ancestors of non-Africans occurred before the divergence of Eurasian groups from each other.

http://www.sciencemag.org/content/328/5979/710.short

Another article on paleogenetics:
http://www.sciencemag.org/content/328/5979/680.summary
 
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