Register | Sign In


Understanding through Discussion


EvC Forum active members: 65 (9162 total)
6 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: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   "Microevolution" vs. "macroevolution."
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.3


Message 11 of 63 (300600)
04-03-2006 1:04 PM
Reply to: Message 10 by Faith
04-03-2006 12:48 PM


Re: It's all a definitional sleight of hand
Faith writes:
I can't define a Kind to genetic specifications..."
Using the creationist definition of macroevolution as evolution between kinds, as long as "kinds" remains without a formal definition then so does "macroevolution". But as Catholic Scientist notes, this isn't really much of a problem. Sure it leaves plenty of ambiguity, but so does the scientific definition of species. While we can't really know whether, for example, dogs and coyotes are different kinds, there is nothing forcing us to consider ambiguous cases in this thread, especially since the definition of kind is not the issue.
...and you can't prove that macroevolution occurs.
In a scientific context "prove" just means "well supported by evidence". There is plenty of evidence for macroevolution, but as subbie clearly states in bold in the OP, "I would like this thread to be limited to a discussion of the definition and usage of these terms, rather than a debate about whether "macroevolution" can be proved."
--Percy

This message is a reply to:
 Message 10 by Faith, posted 04-03-2006 12:48 PM Faith has not replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.3


Message 15 of 63 (300606)
04-03-2006 1:18 PM
Reply to: Message 10 by Faith
04-03-2006 12:48 PM


Re: It's all a definitional sleight of hand
Faith writes:
Nobody ever thought there could be variation beyond whatever a kind is until Darwin, and all Darwin did was suggest how it might be possible, which was nothing more than observing that the principles of domestic breeding occur haphazardly in nature.
This statement from you also bothered me, but I wasn't going to reply because I thought it might tend to draw this thread even more off-topic, but I see Chiroptera has replied, and upon reflection I think it important to provide additional detail. I don't want to derail the thread, and am only posting this to dispell your claim that Darwin derived his theory from "nothing more than" observations of domestic breeding. The chapter headings of Origin of Species are in essence an outline of the areas from which Darwin drew his evidence, so here are the chapter headings:
  • Introduction
  • Chapter I: Variation Under Domestication
  • Chapter II: Variation Under Nature
  • Chapter III: Struggle For Existence
  • Chapter IV: Natural Selection; Or the Survival of the Fittest
  • Chapter V: Laws of Variation
  • Chapter VI: Difficulties of the Theory
  • Chapter VII: Miscellaneous Objections to the Theory of Natural Selection
  • Chapter VIII: Instinct
  • Chapter IX: Hybridism
  • Chapter X: On the Imperfection of the Geological Record
  • Chapter XI: On the Geological Succession of Organic Beings
  • Chapter XII: Geographical Distribution
  • Chapter XIII: Geographical Distribution Continued
  • Chapter XIV: Mutual Affinities of Organic Beings: Morphology: Embryology: Rudimentary Organs
  • Chapter XV: Recapitulation and Conclusion
This should make clear how widely Darwin cast his net for evidence.
--Percy

This message is a reply to:
 Message 10 by Faith, posted 04-03-2006 12:48 PM Faith has replied

Replies to this message:
 Message 17 by Faith, posted 04-03-2006 1:39 PM Percy has replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.3


Message 16 of 63 (300607)
04-03-2006 1:26 PM
Reply to: Message 13 by Faith
04-03-2006 1:11 PM


Re: It's all a definitional sleight of hand
Hi Faith,
I again don't want to take this thread off-topic, but I do want to nip any misunderstandings in the bud.
Faith writes:
And since Percy is on my case for taking Wounded's bait about proof (which is what the challenge to define the Kinds is about)...
Wounded King never said anything about proof. He was only noting the inconsistency of making explicit claims about something that doesn't have a clear definition. It was you who first mentioned proof in the message Wounded King replied to, Message 7:
No, we can't yet define a Kind. But macroevolution, as it is now called in order to avoid confusion, has also not been proved.
And then you mentioned proof again in your reply to Wounded King in Message 10, which is where I stepped in to note that it was off-topic.
--Percy

This message is a reply to:
 Message 13 by Faith, posted 04-03-2006 1:11 PM Faith has replied

Replies to this message:
 Message 18 by Faith, posted 04-03-2006 1:42 PM Percy has not replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.3


Message 22 of 63 (300616)
04-03-2006 1:57 PM
Reply to: Message 17 by Faith
04-03-2006 1:39 PM


Re: It's all a definitional sleight of hand
This is again off-topic, but I just want to jump in again to correct your misstatements.
Faith writes:
The only other actual evidence suggested by Darwin's chapter headings is the fossil record.
Since you've just read the chapter headings, I don't see how you can say this. Let me put the relevant topics in my own words to make clear that Darwin drew on much more than domestic breeding and the fossil record:
  • Change in plants and animals under domestication.
  • Change in plants and animals in the wild.
  • Instinct.
  • Hybridism.
  • The geological record (includes fossil evidence).
  • Geographical distribution.
  • Morphology.
  • Embryology.
  • Vestigial organs.
And that should settle the matter about how widely Darwin sought out evidence for evolution.
Unless you're somehow tying it in to the definitions of microevolution and macroevolution, the rest of your post about the mechanisms of evolution seems even further off-topic. Not that it isn't a great topic for discussion, it's just that it isn't this topic.
--Percy

This message is a reply to:
 Message 17 by Faith, posted 04-03-2006 1:39 PM Faith has replied

Replies to this message:
 Message 25 by Faith, posted 04-03-2006 2:20 PM Percy has replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.3


Message 28 of 63 (300634)
04-03-2006 2:47 PM
Reply to: Message 25 by Faith
04-03-2006 2:20 PM


Re: It's all a definitional sleight of hand
Faith writes:
Seems to me nothing in Darwin's chapter headings could be a proof of evolution, and since the mechanism of natural selection, on which so much seemed to depend at the time, proves no more than domestic selection does, and in fact less since it's a less controlled process, I see no proof of macroevolution whatever in any of that.
Faith, step back for a moment. I'm was not talking about proving macroevolution. I was never talking about proving macroevolution. It literally did not cross my mind when I was composing my posts about Darwin's evidence.
I posted for one reason only, to correct your misstatement that Darwin drew upon only a single line of evidence, domestic breeding. That is not true, and I listed the other lines of evidence he drew upon to show that that is not true. Whether or not the evidence he presented is sufficient to support a theory of common descent is another matter, and it isn't the topic of this thread. Even Darwin's evidence is off-topic - I only posted because I didn't want readers left with the misimpression that Darwin considered only a superficial amount of evidence.
--Percy

This message is a reply to:
 Message 25 by Faith, posted 04-03-2006 2:20 PM Faith has replied

Replies to this message:
 Message 29 by Faith, posted 04-03-2006 3:01 PM Percy has replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.3


Message 32 of 63 (300664)
04-03-2006 4:16 PM
Reply to: Message 29 by Faith
04-03-2006 3:01 PM


Re: It's all a definitional sleight of hand
Faith writes:
{ABE: OK, I went back to the original statement and here's what I said:
Nobody ever thought there could be variation beyond whatever a kind is until Darwin, and all Darwin did was suggest how it might be possible, which was nothing more than observing that the principles of domestic breeding occur haphazardly in nature.
Yes, I quoted this when I replied in Message 15. I understand now from your clarification that you intended to say only that Darwin's proposal of natural selection was just casting onto nature what domestic breeders were already doing. And you are correct. There's actually a deeper picture here that is hinted at when you say that domestic breeding argues against cross-kind change, but this isn't the thread for that discussion.
In the interest of accuracy, the first part of your passage about nobody considering the possibility of change across kinds before Darwin is incorrect. That idea wasn't actually original with Darwin. The idea, though not the word, for evolution was already in the air, and Darwin's grandfather, Erasmus, had dabbled with the idea decades earlier, and it was still an idea in the naturalists' collective repertoir when Darwin came on the scene. But the idea garnered little serious consideration because there was no known mechanism for this type of change. It was Darwin's contribution to provide the mechanism, not the idea, of evolution.
--Percy

This message is a reply to:
 Message 29 by Faith, posted 04-03-2006 3:01 PM Faith has replied

Replies to this message:
 Message 34 by Faith, posted 04-03-2006 4:37 PM Percy has not replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.3


Message 41 of 63 (301347)
04-05-2006 7:57 PM
Reply to: Message 39 by Faith
04-05-2006 6:38 PM


Re: Time and Intent
Faith writes:
That is the theory. But my argument is about what it would take to PROVE it...
In a scientific context the question becomes, "What is the evidence supporting this theory?" At any point during the presentation of evidence you can say, "But you still haven't *proven* the theory," and of course in a technical sense you would be correct because in science theories are never proven, only supported by evidence. So in a scientific context you would have to instead say, "I don't find that evidence convincing," and would hopefully go on to explain why.
...and since we are at a disadvantage in that we cannot witness the supposed changes over those aeons of time,...
Yes, we are at a disadvantage, analogous to the police detective trying to solve a crime that has no witnesses but which does have evidence.
I don't think time can affect the principle involved. Microevolutionary variations don't automatically become macroevolutionary ones simply with the introduction of lots of time.
The key problem for you is the absence of anything preventing the accumulation of microevolutionary changes. Almost every reproductive act creates errors, and in sexual reproduction there's the mixing of alleles. You can take the chimpanzee genome and come up with a sequence of microevolutionary changes that eventually arrives at the human genome. If I were to present you that hypothetical sequence, how would you go about identifying the microevolutionary change that would somehow be prevented from happening and keep the chimp forever a chimp?
However, all he observed was the already familiar processes of what is now called "microevolution" via natural selection.
That might be all he observed of "evolution in action", but it is only a tiny part of his evidence.
He did not prove macroevolution...
Yes, that's true, of course he didn't prove macroevolution. And Newton didn't prove gravity and Einstein didn't prove relativity. But just as Newton and Einstein supported their theories with evidence, Darwin supported his theory of evolution with evidence drawn from artificial and natural selection, hybridism, geological distributions, the fossil record, instinct, morphology, embryology and vestigial organs. Since Darwin's time the evidence has only grown, and in the 1920's the work of population geneticists enabled Darwin's theory to be combined with the science of genetics to form the modern synthesis, otherwise known as the synthetic theory of evolution, which is what most evolutionists actually have in mind when talking about evolution.
To summarize: Time cannot possibly guarantee the kind of changes postulated...
Yes, you are right, time cannot guarantee. But that's because nothing is guaranteed in science. The process requires supplying evidence, not guarantees, and in the case of evolution there is much available evidence.
Just as there is nothing to prevent seconds from accumulating into millennia, which no one person can observe, there is nothing to prevent microevolution from accumulating into macroevolution, and this theoretical framework is consistent with the evidence.
--Percy
Fix typo. --Percy
This message has been edited by Percy, 04-06-2006 09:12 AM

This message is a reply to:
 Message 39 by Faith, posted 04-05-2006 6:38 PM Faith has not replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.3


Message 48 of 63 (301670)
04-06-2006 3:47 PM
Reply to: Message 47 by Faith
04-06-2006 3:26 PM


Re: Time and Intent
Faith writes:
But you aren't starting with pennies, you are starting with all the atoms in the universe from which you need to get very specific combinations.
Alasdair was pointing out an error in the way you're including natural selection in your thinking about probability. The principle is the same whether the objects are pennies or atoms. I expect he and others are willing to explain it again.
Calculate the probability of getting DNA from that.
The topic is micro versus macro evolution, not the origin of life.
--Percy

This message is a reply to:
 Message 47 by Faith, posted 04-06-2006 3:26 PM Faith 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