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Author Topic:   Is There Any Genetic Or Morphological Criterion For "Kind"?
Dr Adequate
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Posts: 16094
Joined: 07-20-2006
Member Rating: 8.2


Message 1 of 40 (352164)
09-25-2006 3:28 PM


How do I tell if two living or fossil species are the same "kind", or belong to two different "kinds"?

With thanks in advance to anyone who's willing to take a crack at answering this, or who can provide me with a link.


Replies to this message:
 Message 3 by RAZD, posted 09-25-2006 11:39 PM Dr Adequate has responded
 Message 5 by Faith, posted 09-26-2006 6:27 AM Dr Adequate has not yet responded
 Message 24 by Minority Report, posted 06-29-2011 6:33 AM Dr Adequate has responded
 Message 30 by Kaichos Man, posted 12-12-2011 5:30 AM Dr Adequate has responded
 Message 35 by dan4reason, posted 12-13-2011 12:16 AM Dr Adequate has not yet responded

  
AdminQuetzal
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Message 2 of 40 (352236)
09-25-2006 6:36 PM


Short But Sweet
Thread moved here from the Proposed New Topics forum.

Edited by AdminQuetzal, : No reason given.


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  • RAZD
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    Posts: 19819
    From: the other end of the sidewalk
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    Message 3 of 40 (352273)
    09-25-2006 11:39 PM
    Reply to: Message 1 by Dr Adequate
    09-25-2006 3:28 PM


    simple answer
    How do I tell if two living or fossil species are the same "kind", or belong to two different "kinds"?

    Easy.

    If there is a definite undeniable evolutionary link between the two species then it is clearly change within a kind.

    If there is no such link then it is two different kinds as it would take a "macro"evolutionary change to get from {A} to {B}.


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    This message is a reply to:
     Message 1 by Dr Adequate, posted 09-25-2006 3:28 PM Dr Adequate has responded

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    Dr Adequate
    Member
    Posts: 16094
    Joined: 07-20-2006
    Member Rating: 8.2


    Message 4 of 40 (352285)
    09-26-2006 1:12 AM
    Reply to: Message 3 by RAZD
    09-25-2006 11:39 PM


    Yes, but nothing is "undeniable", because creationists can deny anything.

    Some of them are still denying speciation, in which case every kind would be a monobaramin.

    On the other hand, if you merely mean irrefutable evidence, then life is a kind; but that's not what creationists think.

    This is why a criterion is needed which doesn't depend on the beliefs of the person applying it.


    This message is a reply to:
     Message 3 by RAZD, posted 09-25-2006 11:39 PM RAZD has not yet responded

      
    Faith
    Inactive Member


    Message 5 of 40 (352313)
    09-26-2006 6:27 AM
    Reply to: Message 1 by Dr Adequate
    09-25-2006 3:28 PM


    Expect it eventually will be defined genetically. But meanwhile I liked kuresu's list of hybrids which seemed to fit with what MJFloresta said about how a kind would be determined by ability to interbreed, even if that had to be tested artificially. I wasn't sure about this because I know there are cases where speciation has occurred and interbreeding ability has been lost though the new breed is certainly of the same kind. In any case I thought this made some kind of sense:

    kuresu's list

    My cleaned-up version of kuresu's list.


    This message is a reply to:
     Message 1 by Dr Adequate, posted 09-25-2006 3:28 PM Dr Adequate has not yet responded

    Replies to this message:
     Message 6 by Quetzal, posted 09-26-2006 8:52 AM Faith has responded
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    Quetzal
    Member (Idle past 3982 days)
    Posts: 3228
    Joined: 01-09-2002


    Message 6 of 40 (352338)
    09-26-2006 8:52 AM
    Reply to: Message 5 by Faith
    09-26-2006 6:27 AM


    Expect it eventually will be defined genetically. But meanwhile I liked kuresu's list of hybrids which seemed to fit with what MJFloresta said about how a kind would be determined by ability to interbreed, even if that had to be tested artificially. I wasn't sure about this because I know there are cases where speciation has occurred and interbreeding ability has been lost though the new breed is certainly of the same kind.

    The problem is that the two parts of this definition of "kind" appear mutually contradictory. I can sort of accept the "ability to interbreed", which is close to the biological species concept. Even though the "kind" definition stretches it a bit to include artificial breeding, it's not that far off (and certainly would be one way of showing that the two organisms are related, even if the F1's are sterile). However, adding in the part about "certainly the same 'kind'" even though reproductively isolated leaves us back in the same place, without a usable definition. "'Kind' = ability to interbreed except when they can't" isn't very useful.

    I'd also like your opinion concerning the second part of the question: how do you determine whether two fossils are the same "kind"? Obviously, an interbreeding test isn't going to work. So what's the criteria?


    This message is a reply to:
     Message 5 by Faith, posted 09-26-2006 6:27 AM Faith has responded

    Replies to this message:
     Message 7 by mjfloresta, posted 09-26-2006 11:37 AM Quetzal has responded
     Message 18 by Faith, posted 09-27-2006 12:18 AM Quetzal has responded

      
    mjfloresta
    Member (Idle past 4104 days)
    Posts: 277
    From: N.Y.
    Joined: 06-08-2006


    Message 7 of 40 (352368)
    09-26-2006 11:37 AM
    Reply to: Message 6 by Quetzal
    09-26-2006 8:52 AM


    My definition for the Kind, as I have oft pointed out, is that individuals of the same kind CAN produce offspring, not that they necessarily will in nature. The issue here is genetics - the actual ability of organisms to produce offspring - not behavior, which may determine whether two organisms in nature [i]will[/w] produce offspring, but say nothing about whether they can or can't.
    This message is a reply to:
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    Replies to this message:
     Message 8 by Dr Adequate, posted 09-26-2006 12:00 PM mjfloresta has responded
     Message 9 by Quetzal, posted 09-26-2006 12:37 PM mjfloresta has not yet responded
     Message 17 by Dr Adequate, posted 09-26-2006 11:02 PM mjfloresta has not yet responded

        
    Dr Adequate
    Member
    Posts: 16094
    Joined: 07-20-2006
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    Message 8 of 40 (352382)
    09-26-2006 12:00 PM
    Reply to: Message 7 by mjfloresta
    09-26-2006 11:37 AM


    My definition for the Kind, as I have oft pointed out, is that individuals of the same kind CAN produce offspring, not that they necessarily will in nature.

    But doesn't this make "kind" the same as the biological species concept? --- "groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups" (Ernst Mayr, my italics).

    If so, then:

    (1) It doesn't solve the Noah's Ark problem.

    (2) We don't need a new word for it.


    This message is a reply to:
     Message 7 by mjfloresta, posted 09-26-2006 11:37 AM mjfloresta has responded

    Replies to this message:
     Message 12 by mjfloresta, posted 09-26-2006 5:52 PM Dr Adequate has responded

      
    Quetzal
    Member (Idle past 3982 days)
    Posts: 3228
    Joined: 01-09-2002


    Message 9 of 40 (352393)
    09-26-2006 12:37 PM
    Reply to: Message 7 by mjfloresta
    09-26-2006 11:37 AM


    MJFloresta writes:

    My definition for the Kind, as I have oft pointed out, is that individuals of the same kind CAN produce offspring, not that they necessarily will in nature. The issue here is genetics - the actual ability of organisms to produce offspring - not behavior, which may determine whether two organisms in nature [i]will[/w] produce offspring, but say nothing about whether they can or can't.

    So what? I already noted that, even though you're stretching the BSC a bit, this was a reasonable definition. Until, of course, you get to the part where two obviously related species can't interbreed, even artificially. Why don't you try actually answering/responding to the post made, rather than simply re-asserting your original point? Try this:

    Quetzal writes:

    "'Kind' = ability to interbreed except when they can't" isn't very useful.

    Faith's contention is that there is some way to objectively identify "kind" even in the absence of the interbreeding criteria.

    After you finish that, you can address the second part of the question, which dealt with how a creationist determines whether two fossil organisms are the same "kind".

    Edited by Quetzal, : wrong attribution


    This message is a reply to:
     Message 7 by mjfloresta, posted 09-26-2006 11:37 AM mjfloresta has not yet responded

    Replies to this message:
     Message 10 by MangyTiger, posted 09-26-2006 3:57 PM Quetzal has responded

      
    MangyTiger
    Member (Idle past 4464 days)
    Posts: 989
    From: Leicester, UK
    Joined: 07-30-2004


    Message 10 of 40 (352427)
    09-26-2006 3:57 PM
    Reply to: Message 9 by Quetzal
    09-26-2006 12:37 PM


    Mistaken identity
    I don't think Tusko will be too happy you mistook him(?) for mjfloresta :)


    Oops! Wrong Planet
    This message is a reply to:
     Message 9 by Quetzal, posted 09-26-2006 12:37 PM Quetzal has responded

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    Quetzal
    Member (Idle past 3982 days)
    Posts: 3228
    Joined: 01-09-2002


    Message 11 of 40 (352442)
    09-26-2006 5:24 PM
    Reply to: Message 10 by MangyTiger
    09-26-2006 3:57 PM


    Re: Mistaken identity
    You're absolutely right. I've fixed it. Bizarre brain burp there...
    This message is a reply to:
     Message 10 by MangyTiger, posted 09-26-2006 3:57 PM MangyTiger has not yet responded

      
    mjfloresta
    Member (Idle past 4104 days)
    Posts: 277
    From: N.Y.
    Joined: 06-08-2006


    Message 12 of 40 (352445)
    09-26-2006 5:52 PM
    Reply to: Message 8 by Dr Adequate
    09-26-2006 12:00 PM


    It's true that Mayr does make that distinction; But as commonly applied, species refers only to those populations that do interbreed, not those that might. Jackals and wolves may be able to interbeed, lions and lynx may be able to interbreed, but no one to my knowledge would call or even think of these organisms as belonging to the same species, respectively. Practically speaking, the concept of species strictly refers to those populations that do interbeed.
    This message is a reply to:
     Message 8 by Dr Adequate, posted 09-26-2006 12:00 PM Dr Adequate has responded

    Replies to this message:
     Message 13 by Coragyps, posted 09-26-2006 6:10 PM mjfloresta has not yet responded
     Message 15 by RickJB, posted 09-26-2006 7:01 PM mjfloresta has not yet responded
     Message 16 by Dr Adequate, posted 09-26-2006 8:09 PM mjfloresta has not yet responded

        
    Coragyps
    Member
    Posts: 5381
    From: Snyder, Texas, USA
    Joined: 11-12-2002
    Member Rating: 8.4


    Message 13 of 40 (352448)
    09-26-2006 6:10 PM
    Reply to: Message 12 by mjfloresta
    09-26-2006 5:52 PM


    Think about Greenish Warblers until I get home and post a bit about them............
    This message is a reply to:
     Message 12 by mjfloresta, posted 09-26-2006 5:52 PM mjfloresta has not yet responded

        
    RickJB
    Member (Idle past 3101 days)
    Posts: 917
    From: London, UK
    Joined: 04-14-2006


    Message 14 of 40 (352453)
    09-26-2006 6:44 PM
    Reply to: Message 5 by Faith
    09-26-2006 6:27 AM


    Faith writes:

    Expect it eventually will be defined genetically.

    I won't be holding my breath....;)


    This message is a reply to:
     Message 5 by Faith, posted 09-26-2006 6:27 AM Faith has not yet responded

      
    RickJB
    Member (Idle past 3101 days)
    Posts: 917
    From: London, UK
    Joined: 04-14-2006


    Message 15 of 40 (352455)
    09-26-2006 7:01 PM
    Reply to: Message 12 by mjfloresta
    09-26-2006 5:52 PM


    mjf writes:

    Jackals and wolves may be able to interbeed, lions and lynx may be able to interbreed, but no one to my knowledge would call or even think of these organisms as belonging to the same species..

    What if a human/chimp hybrid was possible?

    Would that make us both the same "kind"?

    Edited by RickJB, : No reason given.


    This message is a reply to:
     Message 12 by mjfloresta, posted 09-26-2006 5:52 PM mjfloresta has not yet responded

      
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