Two Plus Two Newer Archives  

Go Back   Two Plus Two Newer Archives > Other Topics > Science, Math, and Philosophy

Reply
 
Thread Tools Display Modes
  #41  
Old 08-29-2007, 11:59 AM
luckyme luckyme is offline
Senior Member
 
Join Date: Apr 2005
Posts: 2,778
Default Re: Speciies? you gotta be kidding.

[ QUOTE ]
Would it help the debate at all to come to a compromise whereby the idea of species is useful and explanatory but the edges are blurry? In other words, it's hard to actually draw distinct lines at the borders of each species, but the concept describes a very real distinction between animals?

[/ QUOTE ]

That's essentially a watered down version of what I've been stating, other than the last point which overstates the position 'species' can possibly hold.

A) In many lifeforms there is only an arbitrarily chosen difference between variety and species or any other split you want to make.

B) In lineage studies, changing 'species' every 27 paces or some arbitrary point will add nothing to what you learn or can teach.

C) In those lifeforms , such as mammals, where the ability to interbreed plays a large role in evolution it is still 'just' a major constraint on their future path and not 'the' only influence and it still faces ring species type issues.

C seems the sticking point, but surely ABC make "a VERY REAL distinction" a tough claim to make, unless species were simply built on "the ability to interbreed" and then it would serve the limited ( but important) role that Rduke correctly stresses. Obviously that restricted definition doesn't apply in A and B and is not the lone factor in C.

My split puppy litter on two islands touches on some of that. If one island looks like Hawaii and the other Greenland will the driving force in their evolution be the environment or the isolated gene pool. I asked "have I created two species by splitting them" because they certainly can't interbreed to try and bring down interbreeding to the constraint that it is.

Let's say every 100 years we exchange 1 puppy between islands to slow down the loss of the ability to interbreed. That would modify how they evolve also, but are we going to wait until it's 100% before we call them a new species. WHen it finally happened that mean that a new species appeared in less than 100 years?

I've quoted Dawkins to try and keep myself on target, I'll add a quote from Prof of Genetics, Steve Jones of University College London in his book "Darwins Ghost" p.48 discussing variation and labels -
"For plants and animals - unlike cheese labels - even to discuss whether a particular form is a species or a variety is, quite often, vainly to beat the air."

If species were a cleaned up version of (C) where rings species and hybrids didn't occur then it would serve those restricted areas of biology as the clean, natural joint that Rduke argues for. But they don't and in a large part of nature the more holistic flow arises from genetic study serves much better. Evolution is after all about small changes and slipping 'clean joint species' in places it isn't even helpful needs attention ( as comments by Dawkins and Jones point out).

I 'spose a nutshell of the two positions is that I think evolution could be studied without the concept of species at all ( to take it to the extreme for illustration). We'd study the flow of changes over time and note all the factors driving them including the role isolation of a group plays, whether isolated by islands, mountains or infertile breeding. That is the direction that DNA knowledge tends to send us in anyway. We could computer model evolution without having to teach the computer 'species' ( I'm only guessing but I suspect that's how it is done).

hope that's clearer, luckyme
Reply With Quote
  #42  
Old 08-29-2007, 01:36 PM
Rduke55 Rduke55 is offline
Senior Member
 
Join Date: Aug 2004
Location: Nashville, TN
Posts: 2,958
Default Re: Speciies? you gotta be kidding.

I think that a lot of yours, Dawkins, and Jones' comments are concerning our difficulties putting organisms into groups, both currently and across their evolutionary history. This doesn't mean to me that there aren't groups.

[ QUOTE ]
it is still 'just' a major constraint on their future path

[/ QUOTE ]

This is an understatement. It can be considered the major constraint on their future path. Again, just because it is hard for us to define and that there are transitional groups now does not mean that it's not a real distinction.

[ QUOTE ]
where rings species and hybrids didn't occur

[/ QUOTE ]

But these are essential to the formation of species. Just because something goes from point A to Point B gradually does not mean that those two points aren't different things.

[ QUOTE ]
will the driving force in their evolution be the environment or the isolated gene pool.

[/ QUOTE ]

Both, with varying strengths depending on population size, etc.

[ QUOTE ]
I asked "have I created two species by splitting them" because they certainly can't interbreed to try and bring down interbreeding to the constraint that it is.

[/ QUOTE ]

But they can interbreed - they just can't now because they are separated. What you've done here is give them a better opportunity to speciate.

[ QUOTE ]

I 'spose a nutshell of the two positions is that I think evolution could be studied without the concept of species at all

[/ QUOTE ]

It would be radically different with much, much less explanatory power than what we have now.
Reply With Quote
  #43  
Old 08-29-2007, 04:29 PM
UpstateMatt UpstateMatt is offline
Senior Member
 
Join Date: Nov 2003
Location: raising 6th street
Posts: 119
Default Re: Speciies? you gotta be kidding.

If we lined up 1,000,000 baseball players according to ability, you wouldn't be able to tell the difference in skill between any two people standing next to each other, no matter how hard you watched them practice or play. But that doesn't mean #847,843 has a prayer of hitting #71's curveball.

There's obvious reasons for creating a taxonomy of living things, and grouping together organisms that can reproduce is a sensible category that makes a meaningful distinction.
Reply With Quote
  #44  
Old 08-29-2007, 04:44 PM
luckyme luckyme is offline
Senior Member
 
Join Date: Apr 2005
Posts: 2,778
Default Re: Speciies? you gotta be kidding.

[ QUOTE ]
There's obvious reasons for creating a taxonomy of living things, and grouping together organisms that can reproduce is a sensible category that makes a meaningful distinction.


[/ QUOTE ]

It 'species' could work that way it would be a much more useful tool than it is in many of the problems it creates these days.
Raising issues around the 'species problem' does not equate with suggesting that we ignore how breeding/interbreeding constraints affect the evolution of lifeform.
I'm not sure you're aware that 'species' does not start or stop at 'can fertilely breed' ??

luckyme
Reply With Quote
  #45  
Old 08-29-2007, 08:18 PM
Taraz Taraz is offline
Senior Member
 
Join Date: Feb 2005
Location: CA
Posts: 2,517
Default Re: Speciies? you gotta be kidding.

[ QUOTE ]

It 'species' could work that way it would be a much more useful tool than it is in many of the problems it creates these days.
Raising issues around the 'species problem' does not equate with suggesting that we ignore how breeding/interbreeding constraints affect the evolution of lifeform.
I'm not sure you're aware that 'species' does not start or stop at 'can fertilely breed' ??

luckyme

[/ QUOTE ]

So all you are saying is that our current boundaries are drawn poorly? What would you propose as a better term and set of classifications for these distinctions?

I think some of us might have misunderstood what you were saying because I certainly thought you were saying something else.
Reply With Quote
  #46  
Old 08-30-2007, 02:04 PM
Valentyno Valentyno is offline
Member
 
Join Date: Dec 2005
Location: GTA
Posts: 73
Default Re: Speciies? you gotta be kidding.

BFOD's.

They're rascals when they need to be.

Think of scalar time, not linear. Give it three-dimensional growths against a 'brane matrice.

And you realize at a very, very basic level that every baryonic bit has its opposite (and far more than that, but see above paragraph/statement, you get the idea.)

Since this is still the early 21st, and the advances, while faster, aren't automatic, each and every previous definition shouldn't be thrown out, but be used as a evolutionary concept/frame.

For the previous centuries, it was enough to develop Darwinism, because it was an interpretation that made sense at the time.

And I guess today both creationism and Darwinism and evolution/devolution can be merged based on individual perception.

Art is creation. Because you create, that does not make you an isolated source drawing something out of clay. As ever was, this species draws its art from what it perceives.

Or something. Y'all get the idea. Take tuna. It exists, both as individual fish, schools of fish, and in canned form. It's mutatable because society and progress has made it so. You draw resources when you eat it, and it, in essence, becomes part of you.

Does that make you tuna? No. But the interaction pretty much makes it a Gaean mesh.

GL with the rest.
Reply With Quote
  #47  
Old 08-30-2007, 02:16 PM
Rduke55 Rduke55 is offline
Senior Member
 
Join Date: Aug 2004
Location: Nashville, TN
Posts: 2,958
Default Re: Speciies? you gotta be kidding.

[ QUOTE ]
BFOD's.

They're rascals when they need to be.

Think of scalar time, not linear. Give it three-dimensional growths against a 'brane matrice.

And you realize at a very, very basic level that every baryonic bit has its opposite (and far more than that, but see above paragraph/statement, you get the idea.)

Since this is still the early 21st, and the advances, while faster, aren't automatic, each and every previous definition shouldn't be thrown out, but be used as a evolutionary concept/frame.

For the previous centuries, it was enough to develop Darwinism, because it was an interpretation that made sense at the time.

And I guess today both creationism and Darwinism and evolution/devolution can be merged based on individual perception.

Art is creation. Because you create, that does not make you an isolated source drawing something out of clay. As ever was, this species draws its art from what it perceives.

Or something. Y'all get the idea. Take tuna. It exists, both as individual fish, schools of fish, and in canned form. It's mutatable because society and progress has made it so. You draw resources when you eat it, and it, in essence, becomes part of you.

Does that make you tuna? No. But the interaction pretty much makes it a Gaean mesh.

GL with the rest.

[/ QUOTE ]

Problem solved.
Reply With Quote
  #48  
Old 08-30-2007, 05:40 PM
vhawk01 vhawk01 is offline
Senior Member
 
Join Date: Feb 2006
Location: GHoFFANMWYD
Posts: 9,098
Default Re: Speciies? you gotta be kidding.

[ QUOTE ]
Finally, somebody who seems to agree with me that species ( like most human categories) don't really exist and often just muddy up ones thinking.
Ran across this in Dawkins, The Ancestors Tale -

"If only all the intermediates were still alive, attempting to separate dogs from cats would be a doomed enterprise, as it is with the salamanders and the gulls." ( He had given an example of rings species issues using them.).

He uses a neat thought experiment - move back in time 1000 years at a pop. Each time take a breeding age male or female from the time you are in back one hop. They will be breedable with the older group. Now take a new one from there and hop back another 1000 years and they will be breedable. You'll eventually reach a point where you can't breed with the locals but your current 1000 year co-traveller will be able to. Did you just bump into a new species?

luckyme

[/ QUOTE ]

I agree with you, and I've actually used this exact same Ancestor's Tale argument no less than half a dozen times here. Its one of my favorites.
Reply With Quote
  #49  
Old 08-30-2007, 06:10 PM
luckyme luckyme is offline
Senior Member
 
Join Date: Apr 2005
Posts: 2,778
Default Re: Speciies? you gotta be kidding.

[ QUOTE ]
[ QUOTE ]
Finally, somebody who seems to agree with me that species ( like most human categories) don't really exist and often just muddy up ones thinking.
Ran across this in Dawkins, The Ancestors Tale -

"If only all the intermediates were still alive, attempting to separate dogs from cats would be a doomed enterprise, as it is with the salamanders and the gulls." ( He had given an example of rings species issues using them.).

He uses a neat thought experiment - move back in time 1000 years at a pop. Each time take a breeding age male or female from the time you are in back one hop. They will be breedable with the older group. Now take a new one from there and hop back another 1000 years and they will be breedable. You'll eventually reach a point where you can't breed with the locals but your current 1000 year co-traveller will be able to. Did you just bump into a new species?

luckyme

[/ QUOTE ]

I agree with you, and I've actually used this exact same Ancestor's Tale argument no less than half a dozen times here. Its one of my favorites.

[/ QUOTE ]

Well, I hope you've done better with it. I haven't been able to get past the divorce of 'species' from one of it's better known possible conditions ... interbreeding constraint. If that were all that the use of 'species' entailed, a specific constraint label, what'd be to discuss?

gluck on the 7th try, luckyme
Reply With Quote
  #50  
Old 08-30-2007, 06:15 PM
vhawk01 vhawk01 is offline
Senior Member
 
Join Date: Feb 2006
Location: GHoFFANMWYD
Posts: 9,098
Default Re: Speciies? you gotta be kidding.

[ QUOTE ]
This is a topic that always sticks in my craw. People make it out to be that there's no way to separate these groups into any legitimate categories and that just isn't true with the overwhelming majority of animals (ring-species aside).

Of course species breaks are impossible to locate if you go over the entire time. You're right that the point is that with all the die-off there are reproductively isolated groups in existence that have different selection pressures and evolutionary histories because of that isolation.
Without considering these groups different species we wouldn't have near the understanding of evolution we do.

[/ QUOTE ]

You and I have had this discussion several times, and I get the impression you think I'm saying something I'm not, or asserting something stronger or more controversial than what I'm really trying to say. Basically, exactly what you've said here, thats my main point. If I can get you to admit that, over the span of time, we are all ring species (and in fact, ring life-on-Earth is probably better) then I have just completely demolished the microevolution/macroevolution argument. Of course, you don't subscribe to this argument, but pretend you are an average creationist. If, over time or geography or ANY barrier, we are in fact all just ring species, then there cannot be any mechanism that divides microevolution from macroevolution, and thus, although these terms might have some practical use, they don't represent any true boundary. Maybe a temporal boundary, but thats irrelevant to creationism.

Its an incredibly difficult and counterintuitive point, in my experience, to try to get people to see the beauty and wonder of ring species. Its really just about the coolest concept in evolution, IMO. And this is exactly the reason why.

I use inflammatory and potentially misleading phrases like "speciation doesn't really exist" or "there are no such things as species" and I think that raises red flags for you. I should probably stop doing it, but I have a specific audience in mind when I say things like that. My goal is to try to shake up peoples preconceptions and shock them a little bit, and get them interested in showing me how stupid and wrong I obviously am. Of course, when I say something like that to someone, such as yourself, who fully understands the concept of ring species and how that applies to all living organisms, it really just becomes an exercise in me backpeddling. But thats just because you don't labor under the misconceptions that I'm trying to confront, so the argument doesn't go as I've planned it.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 10:59 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.