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Author Topic:   Ring Species!!
Dr Adequate
Member
Posts: 16097
Joined: 07-20-2006


Message 46 of 50 (520190)
08-19-2009 6:30 PM
Reply to: Message 43 by drpepperandmilk
08-19-2009 5:23 PM


Re: How are ring species evidence for upward change?
Mendel’s?

No, all of them.

You will find that genetics has moved on somewhat since the nineteenth century.

You can’t substantiate a claim by saying you simply “know” something happened.

You asked what proved that such changes have the potential to occur. The fact that they have occurred is surely very good evidence that they have the potential to do so.

By analogy, to show that acorns have the potential to grow into oaks it is sufficient to show that acorns have grown into oaks. It is then not necessary to go into the nitty-gritty of the biological details to prove this same proposition.

The sum of information I’m talking about is the total within each group, not the two “end” groups added together.

Then you have a strange idea of the meaning of the word "sum". What on earth could one mean by the "sum" of the information other than what you get if you add it up? That's what "sum" means.

If you wish to discuss whether one of the two species so produced has less "information" than the original species, then feel free to provide some actual evidence. You could start by saying how you're quantifying information, but as you're a creationist I predict that you will never do so.

My original question phrased a bit differently: If this (ring species) is an example of how progressive changes occur in biological evolution, how do apparent small steps “backward” like this add up to big steps “forward” over time?

This is next to meaningless. If you are going to count speciation as a step "backwards", what are you going to count as a step forwards --- extinction? If you exterminated one of the species in a ring, would you count this as an increase in whatever you mean by "information"?


This message is a reply to:
 Message 43 by drpepperandmilk, posted 08-19-2009 5:23 PM drpepperandmilk has responded

Replies to this message:
 Message 48 by drpepperandmilk, posted 08-21-2009 12:06 PM Dr Adequate has not yet responded

  
RAZD
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Posts: 19890
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 5.5


Message 47 of 50 (520206)
08-19-2009 9:44 PM
Reply to: Message 43 by drpepperandmilk
08-19-2009 5:23 PM


This is not a thread about MACROevolution ...
Hi drpepperandmilk, and welcome to the fray.

Re: How are ring species evidence for upward change?

"Upward change" is a meaningless term in biology. What do you really mean?

What is up?

You can’t substantiate a claim by saying you simply “know” something happened.

Nor can you rebut it with ignorance of the many examples.

http://www.mun.ca/biology/scarr/Pelycodus_gradual.htm

quote:

Click to enlarge

Successive fossils in the Pelycodus fossil record show the gradual evolution of increased size, which can be recognized as a series of species. The coexistence of two simultaneous size trends indicates a speciation event.

Speciation happens, it has been observed in the fossil record, and it has been observed in the field and in the lab.

Take the Ensatina salamanders in CA. Indeed there was variation from one group to the next in color, size, with the ability to breed with neighboring groups remaining intact, until the “end” groups lost this tendency and had their opportunities to breed basically cut in half.

Curiously, this does not follow logically from the evidence. The salamanders are fairly dispersed within each area, and the opportunities that each individual has are related to the number of other individuals within mating distance. If every salamander lives with mating distance of 50 other individuals, there would be no difference in mating potential. If there was a difference at the edges of the areas inhabited by the salamanders that reduced this number, then this edge effect would apply to all salamanders along the edges, regardless of whether they were "end" varieties, "middle" varieties, or hybrid varieties.

Additionally, there is some evidence that the hybrid zones are small because interbreeding is less successful than breeding within a varietal population. There could be problems with compatibility and viability reducing the opportunities of these populations. For these individuals, they could be surrounded by 50 individual salamanders, but not all of them would qualify as potential mates or high on the list of choices (resulting in delayed of missed mating opportunities) and non-viable offspring could be a higher proportion than normal, thus resulting in less production from the opportunities that are accepted.

If this (ring species) is an example of how progressive changes occur in biological evolution, how do apparent small steps “backward” like this add up to big steps “forward” over time?

What's forward? What's backward? Evolution is change, there is no up\down forward\backward higher\lower.

Evolution is the change in hereditary traits in populations from generation to generation.

Speciation is the division of a parent population into reproductively isolated daughter populations.

The isolation is caused by the build up or different hereditary traits in the daughter populations until they don't interbreed.

Once the interbreeding link is broken -- as it is for ring species in spite of having some continued gene flow possible (subject to several generations and natural selection along the way) from one end to the other, the end species are different enough that breeding does not occur -- once the link is broken by a speciation event (as seen in pelycodus above) there is no constraint on the evolution of the daughter populations to remain similar.

Message 40

I'd like to know how the variation observed in ring species demonstrates the potential of MACRO changes, i.e. new major structures.

They demonstrate the potential for one population of similar organisms to become two populations of similar organisms that are different, one from the other, populations. Like exponential growth, this simple mechanism can produce significant differences in populations over time.

If you want to discuss "MACRO changes, i.e. new major structures" then this is not the thread for it.

Try MACROevolution vs MICROevolution - what is it? or Dogs will be Dogs wil be ???

The lack of ability/inclination in the converging groups to breed seems to indicate that significant information from a finite gene pool was lost, not gained.

If you want to discuss "information" gain\loss then try Irreducible Complexity, Information Loss and Barry Hall's experiments

Enjoy.


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This message is a reply to:
 Message 43 by drpepperandmilk, posted 08-19-2009 5:23 PM drpepperandmilk has not yet responded

  
drpepperandmilk
Junior Member (Idle past 3444 days)
Posts: 4
Joined: 08-19-2009


Message 48 of 50 (520409)
08-21-2009 12:06 PM
Reply to: Message 46 by Dr Adequate
08-19-2009 6:30 PM


Re: How are ring species evidence for upward change?
acorns have the potential to grow into oaks

Seeds to trees: Have you really observed potential, or have you concluded potential by what you’ve observed? We can repeatedly test and observe in the present a seed producing a tree, and then be satisfied that a seed grows into whatever kind of tree the seed originated from. Over successive generations, limited varieties appear. This is not the same proposition of common descent of that tree and all life, which you can only hypothesize without observing it in the past or anything like it in the present.

If you are going to count speciation as a step "backwards", what are you going to count as a step forwards"

The much celebrated arrival of the salamander to new species status is not the step backwards. It's the fact that what earned him that status is fewer options for breeding. "Forward" would be the ability to breed with other species of salamander with which he had been previously unable. Or a significant increase in body size. Or development of scales for protection. Or wings. Big teeth. Lose the cumbersome tail and walk upright. Of course, all this would take way to much time to be able to completely observe, yet you still assume that it has occurred.

I don’t know for certain that the end taxa of the ring species refusing to breed with each other is from a loss of genetic information by mutation or otherwise. My point was that it seems at least a small step backwards in an evolutionary scheme, and my original question (in response to the top post in this thread proposing "Is there a better proof for evolution [than] the ring species?") is how this demonstrates the potential of big changes forward. You did state upthread that "ring species don't demonstrate that potential”, so in a way you have answered. It's been suggested that I visit a different thread for discussion of "new major structures" so I may do that. Thanks for the discussion, it was interesting.


This message is a reply to:
 Message 46 by Dr Adequate, posted 08-19-2009 6:30 PM Dr Adequate has not yet responded

Replies to this message:
 Message 49 by Theodoric, posted 08-21-2009 1:04 PM drpepperandmilk has not yet responded

    
Theodoric
Member
Posts: 6317
From: Northwest, WI, USA
Joined: 08-15-2005
Member Rating: 3.3


Message 49 of 50 (520426)
08-21-2009 1:04 PM
Reply to: Message 48 by drpepperandmilk
08-21-2009 12:06 PM


Re: How are ring species evidence for upward change?
The much celebrated arrival of the salamander to new species status is not the step backwards. It's the fact that what earned him that status is fewer options for breeding. "Forward" would be the ability to breed with other species of salamander with which he had been previously unable. Or a significant increase in body size. Or development of scales for protection. Or wings. Big teeth. Lose the cumbersome tail and walk upright. Of course, all this would take way to much time to be able to completely observe, yet you still assume that it has occurred.

Why are these things a step forward? Because in your perception it is a forward development? Not sure how breeding with other salamander species is a step "forward"? You see you need to stop thinking of individuals. Successful changes allow the species or new species to better fit its habitat. A step "forward" would be anything that allows the species to survive, not the individual. Walking upright would in no way be a step forward for a salamander. Also, the whole idea that salamanders could suddenly evolve that ability shows your ignorance. How does walking upright, having scales, wings, big teeth help salamanders exist in their environment.
Mankind is not the ultimately goal of evolution. There is no goal, other than survival.


Facts don't lie or have an agenda. Facts are just facts
This message is a reply to:
 Message 48 by drpepperandmilk, posted 08-21-2009 12:06 PM drpepperandmilk has not yet responded

Replies to this message:
 Message 50 by greyseal, posted 08-27-2009 7:55 AM Theodoric has not yet responded

    
greyseal
Member (Idle past 2034 days)
Posts: 464
Joined: 08-11-2009


Message 50 of 50 (521361)
08-27-2009 7:55 AM
Reply to: Message 49 by Theodoric
08-21-2009 1:04 PM


Re: How are ring species evidence for upward change?
Why are these things a step forward?

I think it's a symptom of godidititis - this idea of "higher" and "lower" animals which has been inherited into the system as a descriptive rather than perjorative matter.

evolution is...sideways. Not really up or down. Towards more complexity, perhaps, but that's another matter.


This message is a reply to:
 Message 49 by Theodoric, posted 08-21-2009 1:04 PM Theodoric has not yet responded

    
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