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Author Topic:   About New Lamarckian Synthesis Theory
Percy
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Posts: 20832
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.6


Message 13 of 264 (674645)
10-01-2012 11:39 AM
Reply to: Message 11 by nwr
10-01-2012 8:31 AM


I think the way Zi Ko is looking at this is that if a behavior can be considered an acquired characteristic, then if that behavior is heritable it could be considered Lamarckian because it would be a heritable acquired characteristic, and it could be considered guided by the environment because the environment could have trained in the behavior, either naturally in the wild or experimentally through laboratory training, or through a classroom, and just through normal day-to-day activities.

Zi Ko: Whether or not I've accurately captured your views, this is an example of the kind of explanation that *you* should be providing. You shouldn't be relying on others to make guesses as to what a bald assertion with no explanation might mean.

--Percy


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 Message 11 by nwr, posted 10-01-2012 8:31 AM nwr has replied

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 Message 17 by zi ko, posted 10-01-2012 2:12 PM Percy has seen this message
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Percy
Member
Posts: 20832
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.6


Message 45 of 264 (675128)
10-06-2012 12:18 PM
Reply to: Message 42 by herebedragons
10-04-2012 9:51 PM


herebedragons writes:

It has been explained that epigenetics is not the same thing as mutation. Now you complain that no one is presenting the evidence for mutations being random.

I just read up a little bit (a very little bit) on epigenetic inheritance to understand how it creates heritable changes if the underlying DNA sequence remains unchanged, and one of the examples was DNA methylation. As explained by Wikipedia:

Wikipedia writes:

It involves the addition of a methyl group to the 5 position of the cytosine pyrimidine ring or the number 6 nitrogen of the adenine purine ring (cytosine and adenine are two of the four bases of DNA). This modification can be inherited through cell division.

If we define mutations as changes to the DNA sequence of nucleotides then this kind of change is not a mutation, but it *is* a change in the DNA, it *is* heritable, and it *can* be caused by the environment. The Wikipedia article on Epigenetics argues at one point that if the genetic code represents the DNA sequence then the "epigenetic code" represents the total state of the cell.

Wikipedia mentions of the environment affecting epigenetic factors mostly mean the local cell environment. For single-celled non-communal organisms one could argue that the environment can guide evolution directly, but anything above this level is much more complicated. Most epigenetic discussion that I read was about internal chemical changes during fetal and juvenile development that turn processes on and off. For any external environmental changes to influence internal cellular processes in, say, a mammal would likely require a long chain of internal effects.

Zi Ko should pick an example of epigenetic inheritance so we have something concrete to talk about.

--Percy


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Percy
Member
Posts: 20832
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.6


Message 47 of 264 (675131)
10-06-2012 12:40 PM
Reply to: Message 44 by zi ko
10-06-2012 12:05 PM


The Time article that Zi Ko is referring to is here: Why Your DNA Isn't Your Destiny

It is well worth a read. It clearly describes some supporting evidence in an organized and well presented manner.

It includes the Lamarck argument that Zi Ko has been making. While Lamarck was wrong to think that acquired characteristics such as cutting off the tails of mice could be inherited, apparently less overt acquired characteristics *can* be inherited, though they are thought to be impermanent and in the absence of the original environmental factor will fade away and be lost.

--Percy


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 Message 44 by zi ko, posted 10-06-2012 12:05 PM zi ko has replied

Replies to this message:
 Message 53 by zi ko, posted 10-10-2012 11:19 AM Percy has replied
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Percy
Member
Posts: 20832
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.6


Message 50 of 264 (675161)
10-07-2012 8:39 AM
Reply to: Message 49 by zi ko
10-07-2012 5:02 AM


Re: Statement of mistake
Hi Zi Ko,

It doesn't matter whether there are quotes around it or who said it, it's just another unsupported assertion. What you need is evidence.

And there apparently *is* evidence out there for something somewhat resembling your point of view, but you're being remarkably inept in exploiting it. Why don't you go back to the Time article and use it to structure your arguments.

--Percy


This message is a reply to:
 Message 49 by zi ko, posted 10-07-2012 5:02 AM zi ko has replied

Replies to this message:
 Message 52 by zi ko, posted 10-10-2012 11:08 AM Percy has seen this message

  
Percy
Member
Posts: 20832
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.6


Message 64 of 264 (675419)
10-11-2012 9:15 AM
Reply to: Message 53 by zi ko
10-10-2012 11:19 AM


zi ko writes:

Yes I agree.But what if the original [environmental] factor will not fade away? Has science any answer on this?

Has science any answer? You're not asking anything complicated. Keeping with the example of DNA methylation, it is modestly heritable. As long as the original environmental factor responsible for the methylation remains present then the methylation will remain present. When the original environmental factor is removed then within a few generations the methylation will disappear.

But getting back to the topic of Lamarckian evolution, DNA methylation is somewhat Lamarckian in that the characteristics it confers are heritable for several generations.

--Percy


This message is a reply to:
 Message 53 by zi ko, posted 10-10-2012 11:19 AM zi ko has replied

Replies to this message:
 Message 65 by zi ko, posted 10-11-2012 3:00 PM Percy has seen this message

  
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