Name It / Claim It: Epigenetics Now Just Another Evolutionary Mechanism

_{Cornelius Hunter
April 19, 2016

Epigenetics, Intelligent Design

1}_{Categories
Epigenetics
Intelligent Design}

Share: Facebook; Twitter/X; LinkedIn; Flipboard; Print; Email

It is often said that all truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident. And so it is with epigenetics which evolutionists opposed and blackballed for a century before finally appropriating it as just another mode of evolutionary change. (see here, here, andhere for more discussion of this history of misdirections regarding Lamarckism and epigenetics). Here is an example of evolutionists, after a century of denial and rejection, claiming epigenetics as their own. Read more

Comments

Origenes @86 Good point.Dionisio_{April 29, 2016
April
04
Apr
29
29
2016
03:53 AM
3
03
53
AM
PST}

gpuccio @81-85,87 Wow! Eccellente! Juicy comments. Thank you!Dionisio_{April 29, 2016
April
04
Apr
29
29
2016
03:44 AM
3
03
44
AM
PST}

Zachriel: 1) Uncoordinated (or minimally coordinated) distributed decisions: a1) Fishes swimming in aquarium: http://www.welovedates.com/date-ideas/first-date-ideas/aquarium-date/ b1) Passersby in a street: http://visitbirmingham.com/files/2012-02-08/NewStreet-ET.jpg c1) Birds: http://www.pageresource.com/wallpapers/wallpaper/flying-birds-apple-animals-blue-sky.jpg 2) Coordinated distributed decisions: a2) Fishes swimming in formation: https://s-media-cache-ak0.pinimg.com/736x/54/17/ab/5417abbff9b7942a7219dc47d4558391.jpg b2) A choreography: http://assets7.capitalxtra.com/2016/05/the-royal-family-dance-crew-1454588979-article-0.png c2) Birds flying in formation: http://betterphotography.in/wp-content/uploads/2011/05/v-formation-rajesh.jpg I think the concept is clear. In all the examples in the second set, some supervising control, based on specific information, gives order and function to the outcome. Which is, I believe, the central concept in ID. And there is nothing here which is even vaguely comparable to the complexity and functional order in C. elegans' first division: http://www.wormbook.org/chapters/www_asymcelldiv.2/asymcelldiv.2.htmlgpuccio_{April 29, 2016
April
04
Apr
29
29
2016
02:42 AM
2
02
42
AM
PST}

Dionisio: Perhaps one reason why the number of biology research papers keeps increasing so fast has to do with their bottom-up approach to investigation? Sometimes don’t they seem barking up the wrong trees? Maybe that’s also why we see so many instances of expressions like “surprisingly” and “unexpectedly” in the biology research papers? What do they expect when they get so surprised by the discoveries they make?
I'm thoroughly convinced that a "bottom-up" view on biology doesn't make any sense. From the level of fermions and bosons one cannot explain the coherence and organization we find at higher levels — a flock of birds notwithstanding. IOWs biology is simply off-limits to true materialism. The only versions of materialism that can join the debate are the ones which incorporate "information", "function", "control", "instructions" and so forth. To his credit Zachriel rejects the acceptance of such teleological concepts, because he holds them to be incompatible with materialism.Origenes_{April 29, 2016
April
04
Apr
29
29
2016
02:22 AM
2
02
22
AM
PST}

Zachriel: 2) Instead, you seem to mean that the decision making, the control, is distributed. But in what sense? It is obvious that the decision making happens in different places and at different times, therefore in that sens it is distributed by default. And that is true also of computer software: decisions are taken in different parts of the processor, at different times. But you seem to imply something different. You discuss the example of the flock of birds. And you say: "Each member need only follow a few basic rules, and the result of these individual decisions result in a global pattern." So, you seem to say: there are separate decision makings in each cell, and they give a global pattern. And so? It is obvious that each cell makes its decisions. And it is obvious that the sum of individual decisions gives a global pattern. You cannot mean something so trivial. At the level of the individual cell, it is obvious that individual parts make their own decisions, and that the sum of individual decisions gives a global pattern in the cell. For example, let's consider the first asymmetric division of the C. elegans zygote: a) PAR-3, PAR-6, PKC-3 "decide" to be restricted the anterior cortex b) PAR-1 and PAR-2 "decide" to be restricted to the posterior cortex c) PAR-4 and PAR-5 "decide to remain distributed evenly throughout the cortex and the cytoplasm. And a lot of other decisions take place, involving many other "actors", just to prepare the first asymmetrical division which will generate two cells with a completely different destiny. But I think that the behaviour of the PAR complex is enough to give an idea. So, each PAR molecule takes individual decisions (obviously as a response to some signals), and there is no doubt that the sum of those decisions gives a global pattern. That's what happens in any software in any functional complex system, and more generally in any machine. In a spreadsheet software, decisions are distributed and give a global functional pattern. In a car engine, decisions are distributed and give a global functional pattern. Please. look well at the word "functional". Because you may well understand that, when decisions are distributed, the global pattern could well not be functional at all. The general principle is: a) When decisions are distributed and coordinated by some supervising program, or set of instructions, or whatever, they can well give a global functional pattern, corresponding to the information in the "supervising set of instructions". b) When decisions are distributed and they are not coordinated in any way by any supervising information, the resulting global pattern is random and not functional at all More about that in next post .gpuccio_{April 29, 2016
April
04
Apr
29
29
2016
02:12 AM
2
02
12
AM
PST}

Zachriel: Now, let's try to understand your repeated argument about "distribution". For example: a) "The decision-making apparatus that forms the global pattern is distributed throughout the entire system, which includes the genome and the epigenome" b) "A Turing Machine can simulate a branching process, but processes linearly. This is distinct from an oak tree, wherein decisions about branching are distributed." c) "So, the decision making is distributed." d) “The control is distributed through the process” I am not sure that I understand really what you mean, so I will make two different hypotheses (although I think that the second is probably the right one): 1) With "distributed" you mean that the information which controls the process in written in many different parts (of the genome and/or epigenome). Now, while this is certainly true, it is also certainly irrelevant. We know all too well that the information can be as fragmented as we like (see for example hard disks), but nothing changes, provided that the system can retrieve it correctly. So, I suppose that this is not what you mean. Let's go on (in next post).gpuccio_{April 29, 2016
April
04
Apr
29
29
2016
01:55 AM
1
01
55
AM
PST}

Zachriel: Let's go yo your post #69, where you are supposed to have answered my questions. Let's make it simple. My main question was: "If you look at some complex software in its machine language form, would you say that it is just a cascade of signals?" You give a comment as follows: "With computers there is a distinction between the processor and the memory of the computer." Is that an answer? No, it isn't. But let's imagine that it is an answer. Reasonably, then it should mean: "No, I would not say that it is just a cascade of signals, because with computers there is a distinction between the processor and the memory of the computer". As an answer, it really makes no sense. If you look at a software running in its machine language form, either you describe it as "just a cascade of signals", or you don't. It seems that you don't. Now, what is the reason for that? You say: in computers there is a memory and there is a processor. But, as I have said, even in cells there are memories (mainly the genome) and processors (the epigenome, the translation system, and so on). The memory (the genome) is read differently in hundreds of different ways according to epigenetic processing. So, where is the difference? My next question, strictly related to the first one, was: "Would you say that there is no set of instructions there?" You "answer": "Computers also generally make a distinction between the program and the data." And so? The cell does, too. You can well consider protein coding genes as "data", and all the rest, for example promoters, enhancers, regulatory RNAs, as "program". Where is the difference? And you have definitely not asnswered the real question, which I will ask again, with some more detail: Looking at a complex software running, of which you can only see the machine language form, you can see two different things: a) The information in machine language form b) The outcome of the running (what the computer does) So, let's say that you are not a machine language monster, and you cannot identify a "set of instructions" in the complex sequence of bits. But you see that the software behaves, for example, as a very good spreadsheet. My question is: "Would you say that there is no set of instructions there?" Yes or no, please. And then an explanation, if possible. To the third question, you comment: "Computers generally work sequentially" But that means nothing. Any algorithm can be more or less sequential, parallel, branching, but in the end each signal determines an outcome, so in a sense it can always be described as a cascade of signals. Again, where is the difference? More on distributed things in the next distributed post.gpuccio_{April 29, 2016
April
04
Apr
29
29
2016
01:30 AM
1
01
30
AM
PST}

Zachriel: "the control is distributed through the process" You keep using that word! I do not think it means what you think it means. :) More in next post. (With your permission, I will give a distributed answer)gpuccio_{April 29, 2016
April
04
Apr
29
29
2016
12:30 AM
12
12
30
AM
PST}

Origenes: "I like your argument. When we look at some complex software at the level of its machine language form, we no longer see instructions and things don’t make sense. Another view point (higher level language) from which things do make sense, is obviously a strong indication of what the software is. Similarly when we look at embryo development as a purely chemical series of events, as Zachriel proposes, things don’t make sense. How can this process work without being controlled? How is homeostasis maintained? It makes much more sense when we look at embryo development as a system with data and procedures." That's exactly my point! Strange that you have understood and expressed it so well, while Zachriel... :)gpuccio_{April 29, 2016
April
04
Apr
29
29
2016
12:26 AM
12
12
26
AM
PST}

Origenes @79
[...] unwilling to answer [...]
Well, it's even worse that that. Note that sometimes you've got links to silly movie clips as the only explanation some folks can come up with in response to serious challenging statements. Perhaps one reason why the number of biology research papers keeps increasing so fast has to do with their bottom-up approach to investigation? Sometimes don't they seem barking up the wrong trees? Maybe that's also why we see so many instances of expressions like "surprisingly" and "unexpectedly" in the biology research papers? What do they expect when they get so surprised by the discoveries they make? However, sometimes being surprised could be good too: I've been wonderfully surprised by amazing grace.Dionisio_{April 28, 2016
April
04
Apr
28
28
2016
08:15 PM
8
08
15
PM
PST}

Gpuccio: The whole cellular machine is an incredibly complex system where data and procedures are strictly interwoven, and while we understand something of data, we still understand very little of the procedures. But that’s exactly what can happen if we look at some complex software in its machine language form.
I like your argument. When we look at some complex software at the level of its machine language form, we no longer see instructions and things don't make sense. Another view point (higher level language) from which things do make sense, is obviously a strong indication of what the software is. Similarly when we look at embryo development as a purely chemical series of events, as Zachriel proposes, things don't make sense. How can this process work without being controlled? How is homeostasis maintained? It makes much more sense when we look at embryo development as a system with data and procedures. It's no surprise to me that Zachriel is unwilling to answer your questions.Origenes_{April 28, 2016
April
04
Apr
28
28
2016
05:58 PM
5
05
58
PM
PST}

Origenes: However there are some striking differences between a flock of birds and embryo development, to name but a few: the birds are interchangeable without disrupting the global flock pattern and although the flock pattern is orderly it lacks specificity and specified parts. Sure. There are vast differences. However, the example suffices to show that global structure doesn't require global command. gpuccio: Why have I the impression that you have not answered my questions in post #68, repeated in post #70? What's the integer number between 68 and 70? gpuccio: Why? As explain, the control is distributed through the process. gpuccio: The branching of an oak tree, which you seem to like so much, is no good model for cell differentiation. It's not a model, but an example of how local decisions can result in a global pattern. Origenes: There is no conceivable bottom-up explanation for the orchestration of this directionality. InconceivableZachriel_{April 28, 2016
April
04
Apr
28
28
2016
02:25 PM
2
02
25
PM
PST}

It is an obvious truth that during embryo development homeostasis (HS) needs to be maintained. Here I would like to argue that HS is not compatible with neither Zachriel’s view nor any materialistic view. When we ponder HS we quickly realize that: —- 1. HS implies orchestrated/coordinated directionality of all parts of the organism. 2. There is no conceivable bottom-up explanation for the orchestration of this directionality. Therefore (from 1 & 2) 3. An explanation for HS must stem from oneness at the level of the whole organism or beyond — which is in direct contradiction to the claims of materialism. Conclusion: HS is not compatible with materialism. Ad (1). If all cells follow their own trajectory there can be no overall coherence and hence no HS. So all the parts of an organism must be coherently aimed at performing HS. N.B. the organism is in a dynamic equilibrium, even a single cell can be said to be never the same during its life cycle, and therefore we witness a constant reshifting and refocusing wrt HS. Also note, during HS, the parts of the organism behave subordinate to the whole, which is obviously suggestive of a hierarchical relationship between whole and the parts. Ad (2). There is no “master-regulator-molecule” in the cell — DNA included — which can even in principle be a cause for a multicellular organism’s HS; any molecule simply operates at the wrong level to do so. Communication between cells is obviously helpful, but a “democracy of cells” cannot produce the dynamic decision-power combined with overview that is required wrt HS. —- HS constitutes a magnificent display of dynamic (living) unity at the macro-level for which there is zero explanation from the level of fermions and bosons. Even without the simple logic provided above, if an organism is a bag of chemicals, what on Earth would be able to keep the dynamic unity/coherence in place? Moreover, each (unpredictable) interaction with the environment (and sequence of interactions) is a threat to HS. Again, the assumption that HS is compatible with materialism ignores basic logic, ignores chemistry and ignores the tendency of the second law.Origenes_{April 28, 2016
April
04
Apr
28
28
2016
10:09 AM
10
10
09
AM
PST}

Zachriel: Why have I the impression that you have not answered my questions in post #68, repeated in post #70? About the comments that you have given: "You’re stretching the analogy too far." Why? "The decision-making apparatus that forms the global pattern is distributed throughout the entire system, which includes the genome and the epigenome." And so? That means only that the procedures are written in the global information in the genome and epigenome. And so? "This is distinct from an oak tree, wherein decisions about branching are distributed." The branching of an oak tree, which you seem to like so much, is no good model for cell differentiation. Branching can be a fractal process, more or less incorporating stochastic components. The branching of the respiratory tree, or of the vascular tree, can have some similarities to the branching of an oak tree. But cell differentiation is all another matter. Cells differentiate in specific phenotypes, completely different one from the other, and in specific places and times and relationships. That is extremely clear in C. elegans, where the 1000 or so cells are well known, and the differentiation process is well observed in every detail (observed, not understood!). When the C. elegans zygote makes its first asymmetric division, generating two completely different daughter cells through an incredibly complex process, there is no branching of anything: that's a complex program which is initiated and performed in that cell. And all the following divisions repeat the process, each time in completely different ways, and with completely different outcomes. Planned, controlled. I really don't understand your problem with instructions being "distributed". How should they be? Aren't instructions distributed in a running software? Isn't the constant exchange of information between the stored information and the recruited information in RAM and CPU memory what keeps the program running? This is so similar to what happens between genome and epigenome! Again, why am I "stretching the analogy too far"? "So, the decision making is distributed." There is a decision making that decides what transciption factors will be transcribed at a certain moment. That happens through other TFs, which regulate the transcription of the final TFs. Which have, as seen, different roles in initiating and maintaining some final transcriptome and phenotype. Acting through other epigenetic levels. Because, as you know, even those cis regulatory elements which bind the specific TFs are present in every cell. So, why do they work only in the right cell at the right moment? Maybe they are inhibited in other contexts. Maybe by methylation of the CpG islands in their promoter regions. Or by some histone code. The simple truth is that, at the right moment and in the right cell: a) The right TFs are expressed to express the final TFs b) The right cis elements are ready to bind them c) The right histone code is present in the appropriate places of the genome d) The right regulatory RNAs are expressed and spliced and processed to regulate the transcription e) and so on, and so on... This global process is different in each kind of cell, for each functional transition. It is in itself dynamic, and never completely the same, even in the same cell type, especially in stem cell pools. So yes, the decision making is distributed. The whole cellular machine is an incredibly complex system where data and procedures are strictly interwoven, and while we understand something of data, we still understand very little of the procedures. But that's exactly what can happen if we look at some complex software in its machine language form. So, will you answer my questions, or not?gpuccio_{April 28, 2016
April
04
Apr
28
28
2016
09:17 AM
9
09
17
AM
PST}

Zachriel: There is no program other than the cascade itself. It’s a sequence of events, each one triggering the next.
According to your view, everything that happens during embryo development, internal or external to cells, is neither controlled by an external program, nor information. So, there is nothing external to the sequence of events that steers the elements involved to their correct locations. IOWs the elements involved have to find their correct locations at the right time on their own. You explain how this works by the flock of birds analogy:
Zachriel:
Origenes: The flight pattern of a flock of birds is controlled by its parts (birds), because each bird is capable of considering its relationship to its neighbor.
That’s right. Each member need only follow a few basic rules, and the result of these individual decisions result in a global pattern.
Can you expand on your concept and this analogy? I can understand that a bird has the ability to keep a correct distance to its neighbors and also how this produces an orderly overall flock pattern. However there are some striking differences between a flock of birds and embryo development, to name but a few: the birds are interchangeable without disrupting the global flock pattern and although the flock pattern is orderly it lacks specificity and specified parts.Origenes_{April 28, 2016
April
04
Apr
28
28
2016
08:43 AM
8
08
43
AM
PST}

gpuccio @71
Curr Top Dev Biol. 2016;116:167-80. doi: 10.1016/bs.ctdb.2015.11.011. Epub 2016 Jan 23. Securing Neuronal Cell Fate in C. elegans. Zheng C, Chalfie M.
Very interesting paper. Thank you for posting the reference to it. BTW, I noticed some of your interlocutors seem to have difficulties understanding your clear comments? :)Dionisio_{April 28, 2016
April
04
Apr
28
28
2016
07:55 AM
7
07
55
AM
PST}

gpuccio: And in cells there is a disctinction between epigenome and genome. It’s the epigenome which processes the genome at each moment. You're stretching the analogy too far. The decision-making apparatus that forms the global pattern is distributed throughout the entire system, which includes the genome and the epigenome. gpuccio: And isn’t a computer algorithm often similar to a branching process? A Turing Machine can simulate a branching process, but processes linearly. This is distinct from an oak tree, wherein decisions about branching are distributed. gpuccio: Transcription factors control neuronal differentiation by acting as “terminal selectors” that determine the specific cell fates of different types of neurons. So, the decision making is distributed. Origenes: If I understand your position correctly, then, it seems to me, precise position of the elements involved is everything. Signaling is based on the relative position of the cells as they differentiate. This can be tested by bisecting or rearranging components during development. Origenes: The flight pattern of a flock of birds is controlled by its parts (birds), because each bird is capable of considering its relationship to its neighbor. That's right. Each member need only follow a few basic rules, and the result of these individual decisions result in a global pattern. Origenes: Are you saying that, similarly, embryo development is controlled by the parts/elements involved, because each element can (just like a bird) find its correct position on its own? Or differentiate in place.Zachriel_{April 28, 2016
April
04
Apr
28
28
2016
06:36 AM
6
06
36
AM
PST}

Zachriel,
Zachriel:
Origenes: Is the precise position at the right time, of the elements involved, critical to a correct unfolding of the sequence of events?
Generally so.
There is a certain laconic aspect to your answer, which I find surprising. If I understand your position correctly, then, it seems to me, precise position of the elements involved is everything. According to you, the information wrt embryo development is not externally specified, so it can be said to be embedded in the position of the elements. What else is there? Similarly, according to evolutionary theory, there is no external design of an organism, so the information can be said to be embedded in the fitness landscape. Am I correct? Here is my question again: Is the precise position at the right time, of the elements involved, critical to a correct unfolding of the sequence of events?
Zachriel:
Origenes: Does the ‘process’/’sequence of events’/’embryo development’ control itself?
Think of the flock example, and then try to answer the question yourself.

Zachriel: A very simple example is how a flock forms a flight pattern. You might think that to form a flight pattern, each bird would have to consider the formation of the pattern, but what really happens is that each bird just considers its relationship to its neighbor.
The flight pattern of a flock of birds is controlled by its parts (birds), because each bird is capable of considering its relationship to its neighbor. Are you saying that, similarly, embryo development is controlled by the parts/elements involved, because each element can (just like a bird) find its correct position on its own?Origenes_{April 28, 2016
April
04
Apr
28
28
2016
01:39 AM
1
01
39
AM
PST}

Zachriel: An example of programs: Curr Top Dev Biol. 2016;116:167-80. doi: 10.1016/bs.ctdb.2015.11.011. Epub 2016 Jan 23. Securing Neuronal Cell Fate in C. elegans. Zheng C, Chalfie M. Abstract Transcription factors control neuronal differentiation by acting as "terminal selectors" that determine the specific cell fates of different types of neurons. The specification of cell fate, however, requires high fidelity, which relies on stable and robust expression of the terminal selectors. Our recent studies in C. elegans suggest that a second set of transcription factors function as reinforcing or protecting factors to stabilize the expression and activity of terminal selectors. Some serve as "guarantors" to ensure the activation and continuous expression of the selectors by reducing stochastic fluctuations in gene expression; others safeguard the protein function of selectors by repressing inhibitors that would block their activity. These transcription factors, unlike the terminal selectors, do not induce specification but secure neuronal cell fate and provide reliability in differentiation.gpuccio_{April 27, 2016
April
04
Apr
27
27
2016
11:59 PM
11
11
59
PM
PST}

Zachriel: "With computers there is a distinction between the processor and the memory of the computer." And in cells there is a disctinction between epigenome and genome. It's the epigenome which processes the genome at each moment. "Computers also generally make a distinction between the program and the data." And in the cell there is a distinction between the program (the whole set of regulatory information, promoters, enhancers, non coding DNA, TADs, etc.) and the data (for example, the protein coding genes). "Computers generally work sequentially." Let me understand. Wasn't it you who looked at cell development as a sequence of cascades? And isn't a computer algorithm often similar to a branching process? It is not clear to me what your distinctions mean, and what value you give to them. However, I don't see that you have answered my main question, so I ask it again: Would you say that there is no set of instructions there? And just for clarity, I repeat the whole context: If you look at some complex software in its machine language form, would you say that it is just a cascade of signals? Would you say that there is no set of instructions there? Would you describe it as a branching process? Would you say that there is nothing external to the process itself controlling that sequence of events?gpuccio_{April 27, 2016
April
04
Apr
27
27
2016
11:34 PM
11
11
34
PM
PST}

Origenes: Does the ‘process’/’sequence of events’/’embryo development’ control itself? Think of the flock example, and then try to answer the question yourself. Origenes: Is the precise position at the right time, of the elements involved, critical to a correct unfolding of the sequence of events? Generally so. gpuccio: If you look at some complex software in its machine language form, would you say that it is just a cascade of signals? With computers there is a distinction between the processor and the memory of the computer. gpuccio: Would you say that there is no set of instructions there? Computers also generally make a distinction between the program and the data. gpuccio: Would you describe it as a branching process? Computers generally work sequentially.Zachriel_{April 27, 2016
April
04
Apr
27
27
2016
06:28 PM
6
06
28
PM
PST}

Zachriel: Just a question for you. If you look at some complex software in its machine language form, would you say that it is just a cascade of signals? Would you say that there is no set of instructions there? Would you describe it as a branching process? Would you say that there is nothing external to the process itself controlling that sequence of events? Just to understand your position.gpuccio_{April 27, 2016
April
04
Apr
27
27
2016
03:09 PM
3
03
09
PM
PST}

Zachriel:
Origenes: So, to be clear, embryo development, is “a sequence of events” and there is nothing controlling that sequence of events.
Nothing external to the process itself.
Does the 'process'/'sequence of events'/'embryo development' control itself? Is the precise position at the right time, of the elements involved, critical to a correct unfolding of the sequence of events?Origenes_{April 27, 2016
April
04
Apr
27
27
2016
03:01 PM
3
03
01
PM
PST}

Origenes: So, to be clear, embryo development, is “a sequence of events” and there is nothing controlling that sequence of events. Nothing external to the process itself. Origenes: So, the sequence of events, depends on the precise position of the elements involved and the presence of the elements themselves and nothing else? Part of the process is the exchange of messenger molecules, which helps cells determine their position within the whole. A very simple example is how a flock forms a flight pattern. You might think that to form a flight pattern, each bird would have to consider the formation of the pattern, but what really happens is that each bird just considers its relationship to its neighbor. https://businessnetworkswdotorg.files.wordpress.com/2015/03/geese-v-formation02.jpgZachriel_{April 27, 2016
April
04
Apr
27
27
2016
02:42 PM
2
02
42
PM
PST}

Zachriel: There is no program other than the cascade itself. It’s a sequence of events, each one triggering the next.
So, to be clear, embryo development, is "a sequence of events" and there is nothing controlling that sequence of events. So, the sequence of events, depends on the precise position of the elements involved and the presence of the elements themselves and nothing else?Origenes_{April 27, 2016
April
04
Apr
27
27
2016
02:14 PM
2
02
14
PM
PST}

Origenes: So there is no epigenetic “program”. What would be a better term? We usually think of a program as a sequence of instructions acting on data. There is no program other than the cascade itself. It's a sequence of events, each one triggering the next. Origenes: Unfolding of what exactly? The sequence of events that results in development. So, in the most primitive bilaterians, there is an asymmetry between dorsal and ventral. This is then modified in more derived organisms so that distance from these poles determines additional differences. This is then modified into still more differences based on the relative position of neighboring cells. http://o.quizlet.com/i/LY8AJFFjsqUnXKHBXaS3Tg_m.jpgZachriel_{April 27, 2016
April
04
Apr
27
27
2016
01:55 PM
1
01
55
PM
PST}

Zachriel,
Z: The word “program” is misleading.
So there is no epigenetic "program". What would be a better term?
Z: You’re thinking of it as something outside having an overview of the process.
No, I'm don't think that a program is capable of overview. However a program can sequence events.
Z: Rather, each step triggers the next steps in a branching pattern.
But there is no program or information that controls the sequence of the cascade?
Z: There is no overview (...),
Do you mean: "there is nothing controlling the cascade/embryo development"?
Z: (...) but an unfolding.
Unfolding of what exactly?Origenes_{April 27, 2016
April
04
Apr
27
27
2016
10:28 AM
10
10
28
AM
PST}

Origenes: Are you saying that the cascade — the embryo development — is controlled by an epigenetic program? The word "program" is misleading. You're thinking of it as something outside having an overview of the process. Rather, each step triggers the next steps in a branching pattern. There is no overview, but an unfolding. Origenes: Feel free to explain why the compatibility does not pose a conundrum for evolutionary theory. Again, we have little idea what you are asking. You might want to expand on your view somewhat.Zachriel_{April 27, 2016
April
04
Apr
27
27
2016
09:52 AM
9
09
52
AM
PST}

Zachriel:
Origenes: is it your position that this cascade — the embryo development — is controlled by a genetic program?
Embryogenesis is epigenetic, of course.
Are you saying that the cascade — the embryo development — is controlled by an epigenetic program?
Zachriel: Because your question presupposes that it poses a conundrum.
Feel free to explain why the compatibility does not pose a conundrum for evolutionary theory.Origenes_{April 27, 2016
April
04
Apr
27
27
2016
09:04 AM
9
09
04
AM
PST}

Origenes: is it your position that this cascade — the embryo development — is controlled by a genetic program? Embryogenesis is epigenetic, of course. Origenes: You again fail to respond to my question about Venter’s Syn 3.0, which I take as an admission that its compatibility with an existing epigenome poses a conundrum for evolutionary theory. Because your question presupposes that it poses a conundrum.Zachriel_{April 27, 2016
April
04
Apr
27
27
2016
06:13 AM
6
06
13
AM
PST}

Prev 1 2 3 4 Next

You must be logged in to post a comment.

Leave a Reply