Register | Sign In


Understanding through Discussion


EvC Forum active members: 65 (9162 total)
5 online now:
Newest Member: popoi
Post Volume: Total: 915,817 Year: 3,074/9,624 Month: 919/1,588 Week: 102/223 Day: 13/17 Hour: 0/1


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Paper Discussion: Epigenesis and Complexity: The Coming Revolution in Biology
Elmer
Member (Idle past 5904 days)
Posts: 82
Joined: 01-15-2007


Message 6 of 12 (441892)
12-19-2007 8:23 AM
Reply to: Message 5 by mobioevo
12-18-2007 10:50 PM


Hi mobioevo;
I'm not really interested in critiquing or defending a certain author's (somewhat dated) opinion on certain issues. I'd rather discuss the issues on their own merits.
That is, if you wish to dicuss the notion of 'genetic determinism', and/or the supposed role played by that supposed phenomenon in heredity and/or evolution, and/or the role that epigenetics plays in evolution, that would suit me far better.
In that light, when you say--
My answers to the authors critique of genetic determinism is, so what.
I think that just about everybody has now denied and distanced themselves from the old, 'genetic determinism' model. The answer to your 'so what' is that the selectionist approach to evolution, being dependent upon Fisher, Haldane, and Wright's RM+NS model, does not hold water if those random mutations are not solely responsible for, and do not entirely compel, phenotypic traits and their variations. That is, how can random genetic mutations be the cause of evolution if genes are not the determining cause of traits? If, as modern science shows, 'genes' do not 'cause' traits, that is, do not compel and determine traits but only enable and facilitate their development, then how can random genetic mutation be said to be responsible for the origins of biological novelty? To enable and to facilitate is not the same as to cause.
Mechanisms are compelling causes, not the conditions that enable them to operate. A forest fire is not caused by dry timber, although that does enable one; only a flame from a fire started by a match or a lightning bolt is the direct, immediate and compelling cause. If 'genes' are only the 'dry timber' wrt evolution and development, then what is the 'flame'?
Evolution needs to act on hereditary information.
How so? This sounds good, but what does it really mean? For one thing, evolution is an action, not an actor.
Whether this hereditary information is genetic, protein, RNA, methylation patterns, or cell membranes, it does not change the fact that they all are hereditary.
Again, meaning what? Pre-existing? That won't account for novelty, for origins, for evolution.
A knowledge of epigenetic phenomenon only confirms that what is the hereditary unit is the ultimate source of selection.
Says who? From wikipedia, 'epigenetics'--
"Epigenetics is distinct from epigenesis, which is the long-accepted description of embryonic morphogenesis as a gradual process of increasing complexity, in which organs are formed de novo (as opposed to preformationism). However, because all of the cells in the body inherit the same DNA sequences (with a few exceptions, such as B cells), cellular differentiation processes crucial for epigenesis rely almost entirely on epigenetic rather than genetic inheritance from one cell generation to the next. [bold added]
Since morphogenesis is responsible for the actual trait, and since the expressed trait is all that 'natural selection' has to work with, and since morphogenesis relies upon epigenetic, ('not genetic'), inheritance, then the 'gene' cannot be "the ultimate source of selection". Even assuming, [which I do not], that 'selection' means anything.

This message is a reply to:
 Message 5 by mobioevo, posted 12-18-2007 10:50 PM mobioevo has not replied

Replies to this message:
 Message 7 by AdminWounded, posted 12-19-2007 1:12 PM Elmer has replied

  
Elmer
Member (Idle past 5904 days)
Posts: 82
Joined: 01-15-2007


Message 9 of 12 (442017)
12-19-2007 4:54 PM
Reply to: Message 7 by AdminWounded
12-19-2007 1:12 PM


Re: Veering off topic
Could the above post serve as the PNT required, under the heading, "Is 'genetic determinism' empirically valid, and is it essential to the "Modern Synthesis"? I've never started a thread in this forum, so I do not know how such things should be set up.

This message is a reply to:
 Message 7 by AdminWounded, posted 12-19-2007 1:12 PM AdminWounded has not replied

Replies to this message:
 Message 10 by RAZD, posted 12-19-2007 5:31 PM Elmer has not replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024