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Author Topic:   New Species Creation?
Inquisitive Believer
Inactive Member


Message 1 of 16 (48643)
08-04-2003 3:34 PM


Hi,
I'm new to this board...this is my first post, in fact. Could someone point me in the right direction in this (I'm tired of searching online, only to find half-baked arguments on both sides that are riddled with sarcasm, but backed by little scientific fact)?
I'm searching for information regarding the mutation of an organism into a different organism (as opposed to a variation of the same organism). I hope that makes sense. I've read some arguments that indicate that this has happened, and I'd love to read further on the subject.
Thanks in advance
[This message has been edited by Inquisitive Believer, 08-04-2003]

Replies to this message:
 Message 2 by mark24, posted 08-04-2003 3:56 PM Inquisitive Believer has replied
 Message 3 by kjsimons, posted 08-04-2003 4:10 PM Inquisitive Believer has replied

  
mark24
Member (Idle past 5195 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 2 of 16 (48644)
08-04-2003 3:56 PM
Reply to: Message 1 by Inquisitive Believer
08-04-2003 3:34 PM


Inquisitive,
Welcome to EvC!
I'm not clear on what you want. Speciation in a single generation, or large scale morphological change in a single generation?
Mark
------------------
Occam's razor is not for shaving with.

This message is a reply to:
 Message 1 by Inquisitive Believer, posted 08-04-2003 3:34 PM Inquisitive Believer has replied

Replies to this message:
 Message 4 by Inquisitive Believer, posted 08-04-2003 5:18 PM mark24 has replied

  
kjsimons
Member
Posts: 821
From: Orlando,FL
Joined: 06-17-2003
Member Rating: 6.7


Message 3 of 16 (48646)
08-04-2003 4:10 PM
Reply to: Message 1 by Inquisitive Believer
08-04-2003 3:34 PM


I'm searching for information regarding the mutation of an organism into a different organism (as opposed to a variation of the same organism).
There is a very good website that spells out in detail, or links to details, the specifics of speciation/macroevolution.
http://www.talkorigins.com
specifically:
29+ Evidences for Macroevolution: The Scientific Case for Common Descent

This message is a reply to:
 Message 1 by Inquisitive Believer, posted 08-04-2003 3:34 PM Inquisitive Believer has replied

Replies to this message:
 Message 5 by Inquisitive Believer, posted 08-04-2003 5:22 PM kjsimons has not replied

  
Inquisitive Believer
Inactive Member


Message 4 of 16 (48654)
08-04-2003 5:18 PM
Reply to: Message 2 by mark24
08-04-2003 3:56 PM


I was looking for speciation in a single generation. I wasn't aware that large scale morphological change had ever ocurred in a single generation.

This message is a reply to:
 Message 2 by mark24, posted 08-04-2003 3:56 PM mark24 has replied

Replies to this message:
 Message 6 by mark24, posted 08-04-2003 5:30 PM Inquisitive Believer has replied

  
Inquisitive Believer
Inactive Member


Message 5 of 16 (48655)
08-04-2003 5:22 PM
Reply to: Message 3 by kjsimons
08-04-2003 4:10 PM


Thank you very much. The site is very comprehensive and useful.

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mark24
Member (Idle past 5195 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 6 of 16 (48656)
08-04-2003 5:30 PM
Reply to: Message 4 by Inquisitive Believer
08-04-2003 5:18 PM


Inquisitive,
I wasn't aware that large scale morphological change had ever ocurred in a single generation.
It has, in fact, many of the polyploid plants are significantly larger than their "mono"ploid counterparts, but that's about it as far as I'm aware.
Single generation speciation occurs via polyploidy, the replication of the entire genome. There is good evidence this is common in plants, possibly much less common in animals.
Some more information
Mark
------------------
Occam's razor is not for shaving with.
[This message has been edited by mark24, 08-04-2003]

This message is a reply to:
 Message 4 by Inquisitive Believer, posted 08-04-2003 5:18 PM Inquisitive Believer has replied

Replies to this message:
 Message 7 by Inquisitive Believer, posted 08-05-2003 12:50 AM mark24 has not replied
 Message 9 by Andya Primanda, posted 08-05-2003 5:07 AM mark24 has not replied

  
Inquisitive Believer
Inactive Member


Message 7 of 16 (48704)
08-05-2003 12:50 AM
Reply to: Message 6 by mark24
08-04-2003 5:30 PM


Thank you very much for this.
Whew! Wading through all of this makes me wish I had either paid closer attention in high school biology, or at the very least taken some entry level genetics stuff in university.

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Replies to this message:
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crashfrog
Member (Idle past 1467 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 8 of 16 (48705)
08-05-2003 1:06 AM
Reply to: Message 7 by Inquisitive Believer
08-05-2003 12:50 AM


Wading through all of this makes me wish I had either paid closer attention in high school biology
It's probably not your fault - there wasn't anything there to pay attention to in the first place. (I paid pretty close attention and never heard anything about the actual mechanisms of speciation.) I think it's a failure of high school biology programs that largely tip-toe around evolutionary mechanisms in deference to imagined creationists waiting in the wings to decend on the school.

This message is a reply to:
 Message 7 by Inquisitive Believer, posted 08-05-2003 12:50 AM Inquisitive Believer has not replied

  
Andya Primanda
Inactive Member


Message 9 of 16 (48739)
08-05-2003 5:07 AM
Reply to: Message 6 by mark24
08-04-2003 5:30 PM


Speciation by other means?
Since we're talking speciation here, I was wondering if anybody entertains Lynn Margulis' idea that some speciation occured through symbiosis? I read her 'Acquiring Genomes' and she does not seem content with the Mayr formula of geographic speciation. Is there any recorded case of symbiotic speciation?
Maybe I should try to confirm it myself on my animals. Termites have various bacterial and protist symbionts, could it be that different termite species have different symbionts, or, better yet, we could trace the evolution of termite species by comparing their gut contents?

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Quetzal
Member (Idle past 5872 days)
Posts: 3228
Joined: 01-09-2002


Message 10 of 16 (48742)
08-05-2003 5:55 AM
Reply to: Message 9 by Andya Primanda
08-05-2003 5:07 AM


Re: Speciation by other means?
There are quite a few examples of organisms we consider "species" that are actually symbionts. Lichens, portuguese man-of-war, etc. Dr. Margulis, unfortunately, has gone way outboard by proclaiming that symbiosis is the primary means of speciation. I don't think that contention is even remotely supported. Development of genetic incompatibility through geographic or behavioral isolation remains the key ingredient in speciation. (See for example, Orr 1995, "The Population Genetics of Speciation: The Evolution of Hybrid Incompatibilities", Genetics 139:1805-1813).
Where I think Margulis might have a better case is in early metazoan evolution - how did those first cells or multi-cellular critters evolve? In this case, symbiosis and serial endosymbiosis seems to be a pretty likely scenario.
And yeah, assuming termites are like ants in that respect, each species should have different gut bacterial symbionts that evolved along with their hosts.

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Wounded King
Member
Posts: 4149
From: Cincinnati, Ohio, USA
Joined: 04-09-2003


Message 11 of 16 (48758)
08-05-2003 7:31 AM
Reply to: Message 10 by Quetzal
08-05-2003 5:55 AM


How valid is it to even talk about speciation within unicellular asexual populations and compare it to that seen in multicellular sexually reproducing populations, the criteria are obviously not the same there can be no reproductive isolation in the asexual organism, I am ignoring lateral transfer as that just makes things even more complicated.
Speciation in the unicellular asexuals can simply be a heritable gain or loss of some specific structural or genetic feature,the proto-mitochondrion for example, and is distinct from the speciation seen in sexually reproducing multicellular organisms.

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Replies to this message:
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mark24
Member (Idle past 5195 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 12 of 16 (48763)
08-05-2003 8:39 AM
Reply to: Message 11 by Wounded King
08-05-2003 7:31 AM


Wounded King,
I agree, it is simply an arbitray decision by us that decides when an asexual species speciates. The same goes for fossil lineages, for example, when exactly does a fish become a basal tetrapod, or when does an Australopithecine become Homo?
Mark
------------------
Occam's razor is not for shaving with.

This message is a reply to:
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Replies to this message:
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MrHambre
Member (Idle past 1393 days)
Posts: 1495
From: Framingham, MA, USA
Joined: 06-23-2003


Message 13 of 16 (48767)
08-05-2003 9:13 AM
Reply to: Message 12 by mark24
08-05-2003 8:39 AM


The arbitrary nature of such distinctions is the hallmark of Darwinism. I realize this thread's title (the c-word) gives away its hidden agenda, but is species essentialism making a comeback? Can't we give our inquisitive friend a lesson in the Tree of Life?
------------------
En la tierra de ciegos, el tuerco es el Rey.

This message is a reply to:
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Replies to this message:
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Quetzal
Member (Idle past 5872 days)
Posts: 3228
Joined: 01-09-2002


Message 14 of 16 (48868)
08-06-2003 3:13 AM
Reply to: Message 11 by Wounded King
08-05-2003 7:31 AM


I don't disagree WK. About the only useful distinction you can make with unicellular organisms is clonal lineage. Mayr (or somebody) coined the term "agamaspecies" to describe what happens when bacterial lineages (for example) diverge through conjugation/mutation/etc and the intermediate lineages die out or disappear. It's an even squishier concept than species - and we all know how indeterminate that is. After all, unlike the pre- or post-zygotic barriers in sexually reproducing organisms or the instant speciation by polyploidy, there's literally no barrier to preventing these agamaspecies from re-homogenizing down the road. Still, I think conceptually for the purposes of this particular discussion, the idea can be used.
Anyway, I was talking about serial endosymbiosis creating instant new single cell organisms and hence new clonal lineages and hence new "species". Isn't that basically the scenario for the encorporation of mitochondria and chloroplasts, and possibly other organelles, in the first eukaryotes? It's not that great a stretch of imagination to get from there to colony organisms to colonial organisms with specialization like the man-of-war.
Anyway, this is way beyond my expertise. Someone might want to chime in here.

This message is a reply to:
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Inquisitive Believer
Inactive Member


Message 15 of 16 (48919)
08-06-2003 10:40 AM
Reply to: Message 13 by MrHambre
08-05-2003 9:13 AM


The arbitrary nature of such distinctions is the hallmark of Darwinism. I realize this thread's title (the c-word) gives away its hidden agenda, but is species essentialism making a comeback? Can't we give our inquisitive friend a lesson in the Tree of Life?
Actually, I thought my user name made it quite clear where I am coming from. I make no secret that I "believe", however, I put inquisitive in my name because I am here to learn. I was very excited to find this forum because it's a great resource, and is full of people more learned than I am. My mind is open, and I am here to explore the evidence. I don't find scientific evidence threatening to my beliefs in the least. I LOVE learning, and being given things to mull over.
Some other users already pointed me in the direction of very comprehensive reading material (some of which is admittedly a little beyond my grasp), so again, I thank them.
If you see my posts in the future, I would appreciate it if you take them at face value, since again, I am here to learn, and am not ashamed to admit that I know very little about the subject (hence the fact that you won't see me posting much, except to pose questions for more information).
Now...another question...what is species essentialism?

This message is a reply to:
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Replies to this message:
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