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Author Topic:   Definition of Species
Dr Jack
Member (Idle past 388 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 46 of 450 (540201)
12-22-2009 5:17 PM
Reply to: Message 43 by herebedragons
12-22-2009 2:50 PM


Re: Quality sources
My apologies, Mr. Jack, but what consitutes a "credible" source as opposed to a "crank website"? I am avoiding "creationist" sites as they are "crank" or "bogus". But this was not a creationist site.

Not all crank sites are creationist. And I was probably a bit harsh; it's not readily obvious which sites are or aren't crank at the first blush - it's one of the joys of the internet. None-the-less macroevolution.net is a crank site promoting a crazy idea cooked up by its owner.

I don't believe I quoted anything out of context. I did edit some content because I felt it was unnecessary to the discussion and sorta lengthy. So I don't see how I am guilty of quote mining.

To be clear I wasn't accusing you of quote mining, I was accusing your source of quote mining.


This message is a reply to:
 Message 43 by herebedragons, posted 12-22-2009 2:50 PM herebedragons has responded

Replies to this message:
 Message 50 by herebedragons, posted 12-23-2009 10:52 AM Dr Jack has responded

  
Blue Jay
Member (Idle past 981 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 47 of 450 (540204)
12-22-2009 5:29 PM
Reply to: Message 42 by Coyote
12-22-2009 2:21 PM


Re: Baraminology
Hi, Coyote.

Coyote writes:

Actually baraminology seeks to justify the biblical concept of kinds, and to make it sound scientific at the same time.

It is not a field of research because no conclusions can be arrived at other than those specified in scripture. It is pure religious apologetics.

You know I won't argue with any of this.

But, I'm trying to be generous for the sake of Herebedragons, who comes off to me as open-minded, intelligent and at least tentaive about the ideological aspects of creationism.

Libeling ideology runs the risk of making one's own argument appear just as ideological in nature. We dismiss baraminology because of its failure to correctly utilize empirical methodologies, not because of whatever ideological piffle it chooses to utilize instead.

We can convey the same message while entirely avoiding the emotionally-charged, polarizing topics if we simply stick to discussion of the empirical issues, which, in my appraisal, HBD seems more than willing to consider.


-Bluejay (a.k.a. Mantis, Thylacosmilus)

Darwin loves you.


This message is a reply to:
 Message 42 by Coyote, posted 12-22-2009 2:21 PM Coyote has not yet responded

  
Blue Jay
Member (Idle past 981 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 48 of 450 (540210)
12-22-2009 5:50 PM
Reply to: Message 44 by herebedragons
12-22-2009 3:20 PM


Re: Baraminology
Hi, Herebedragons.

HBD writes:

Creationists are constantly being asked to define what a "kind" is. I personally am not sure it is really necessary or practical or maybe even possible, but if a group of creationists are attempting to come up with a definition, maybe their work should be based on the data, not on the fact they are trying to define "kind".

Agreed.

But again, the entire concept of baraminology is based on the alleged existence of distinctions between baramins when there is no empirical reason to believe that such distinctions exist.

Phylogenetics and baraminology both incorporate evolution, or gradual changes over time. But, baraminology further incorporates a concept of limitations on the amount of change that can occur.

Are you familiar with the principle of parsimony? Basically, it means you don't propose a new factor in a system unless you have empirical reasons to do so.

So, what are the empirical reasons for suspecting that evolution can only go so far?


-Bluejay (a.k.a. Mantis, Thylacosmilus)

Darwin loves you.


This message is a reply to:
 Message 44 by herebedragons, posted 12-22-2009 3:20 PM herebedragons has responded

Replies to this message:
 Message 49 by herebedragons, posted 12-23-2009 10:17 AM Blue Jay has responded

  
herebedragons
Member (Idle past 15 days)
Posts: 1513
From: Michigan
Joined: 11-22-2009


(1)
Message 49 of 450 (540286)
12-23-2009 10:17 AM
Reply to: Message 48 by Blue Jay
12-22-2009 5:50 PM


Re: Baraminology
Hi Bluejay

It's good to read true open-mindedness for a change!

Wow! Thanks. I think that is just about the highest compliment I could hope to receive on a site like this. I do believe that God created life and that the Bible is true. However, I don’t think that the Bible needs to be translated literally word for word true. One thing the Bible teaches is that God is a God of truth. Why then, would the observed evidence be deceptive or untrue? That is why I came to this forum, to discuss my doubts and concerns with evolution and creation alike. I want to gain knowledge and understanding of this incredibly complex and beautiful world in which we live in (that’s something both creationist and evolutionist can agree on). I think your comment

Libeling ideology runs the risk of making one's own argument appear just as ideological in nature.

is spot on and contributes to meaningless and fruitless arguments (on both sides). I personally am trying to avoid this type of debate and stick to what is beneficial to my better understanding of life.

Well, that’s my ideological rhetoric for the day. lol.

So, what are the empirical reasons for suspecting that evolution can only go so far?

I suppose it is the same type of reasons that scientists are investigating abiogenesis - we want to understand the beginnings. Did life come from a few created types or “kinds” or did we come from a protein “soup”. Both ideas are equally ideological and theoretical in nature. Yet, abiogenesis has the “advantage” of being a naturalistic solution and therefore, empirical.

I am not trying to build a case in favor of Bariminology, but I do question the seemingly off-handed dismissal of anything that goes against mainstream science. So many scientific breakthroughs were based on concepts that went against “conventional” thought.

But, at this point I think I have an opinion on Baraminology similar to yours:

As a lifelong Christian, I would be very interested if such data were uncovered, but I cannot honestly characterize the basis of the field of baraminology as anything greater than wishful thinking, so I am required by my personal sense of integrity to reject it as a legitimate academic pursuit. Maybe the future will change my mind, I'm not sure, but my skepticism for that is currently very high.

The problem is that since their research is rejected by mainstream science, no matter what their findings are, they are going to be dismissed. You’ll never see a program on Discovery Channel called “Scientists Prove the Existence of Biblical Kinds” because they are not doing anything “scientific” nor are they "scientists".

Thanks


This message is a reply to:
 Message 48 by Blue Jay, posted 12-22-2009 5:50 PM Blue Jay has responded

Replies to this message:
 Message 52 by Blue Jay, posted 12-23-2009 7:57 PM herebedragons has responded
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herebedragons
Member (Idle past 15 days)
Posts: 1513
From: Michigan
Joined: 11-22-2009


Message 50 of 450 (540294)
12-23-2009 10:52 AM
Reply to: Message 46 by Dr Jack
12-22-2009 5:17 PM


Re: Quality sources
Fair enough. I do try to check my sources to be sure they are credible, but it's not always easy. I would also like to point out that just because a source is "crank" doesn't mean there is no useful information from that source, one would just need to use more caution when accepting information as fact. Also I would note it is quite diffucult to argue a contrary position using the same sources as everyone else, and that's kinda the point of this forum, to discuss conflicting points of view. So, personally, I would prefer to be told "That is not credible information because ..."

In this case, I really wasn't trying to argue about marsupial identification, but merely trying to point out the difficulties of defining the concept of species. What are your thoughts about our ability to define and identify the concept of species with a significant amount of accuracy and precision?

Thanks

Edited by herebedragons, : No reason given.


This message is a reply to:
 Message 46 by Dr Jack, posted 12-22-2009 5:17 PM Dr Jack has responded

Replies to this message:
 Message 51 by Dr Jack, posted 12-23-2009 11:32 AM herebedragons has responded

  
Dr Jack
Member (Idle past 388 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


(1)
Message 51 of 450 (540297)
12-23-2009 11:32 AM
Reply to: Message 50 by herebedragons
12-23-2009 10:52 AM


Re: Quality sources
In this case, I really wasn't trying to argue about marsupial identification, but merely trying to point out the difficulties of defining the concept of species.

You're quite right to point out difficulties with identification in the fossil record, you just picked the wrong example. Plants are your best bet, or seaweed. It's not uncommon for different parts of a plant (leaves, seeds, etc.) to end up classified as different species, and the problem is even worse with species that exihibit alternation of generations with very different generations.

This isn't limited to the fossil record, by the way, it occurs even today. Earlier this year a paper was published showing that what had previously been thought of as three species of fish are, in fact, male, female and juvenile of the same species (link.

There's no doubt that such errors of classification have occured in the fossil record.

What are your thoughts about our ability to define and identify the concept of species with a significant amount of accuracy and precision?

The concept of species is not a well defined concept, but it is very useful because it approximates to a natural classification providing you're looking at a reasonably narrow slice of time. It also works pretty well for the kind of large multi-cellular organisms that form the familiar backdrop to our world.

So, in my view, species aren't "real" but they are useful because they describe groups of organisms where investigating the properties of one of that group usefully generalises to all of them, and they are frequently a reasonable level at which to investigate the evolutionary patterns within populations.

I wrote a longer post about this in a another thread: The problem of species

Edited by Mr Jack, : Missing tag

Edited by Mr Jack, : Added link for three fish


This message is a reply to:
 Message 50 by herebedragons, posted 12-23-2009 10:52 AM herebedragons has responded

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Blue Jay
Member (Idle past 981 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 52 of 450 (540320)
12-23-2009 7:57 PM
Reply to: Message 49 by herebedragons
12-23-2009 10:17 AM


Off-handed dismissal
Hi, HBD.

HBD writes:

I am not trying to build a case in favor of Bariminology, but I do question the seemingly off-handed dismissal of anything that goes against mainstream science.

This makes me a bit curious: what makes the dismissal of baraminology by mainstream science seem off-handed to you?

I provided the reason why it is dismissed:

Bluejay, post #48, writes:

...the entire concept of baraminology is based on the alleged existence of distinctions between baramins when there is no empirical reason to believe that such distinctions exist.

What do you think of that reason? Is it not a good reason to dismiss an idea? Why?


-Bluejay (a.k.a. Mantis, Thylacosmilus)

Darwin loves you.


This message is a reply to:
 Message 49 by herebedragons, posted 12-23-2009 10:17 AM herebedragons has responded

Replies to this message:
 Message 53 by Coyote, posted 12-23-2009 8:18 PM Blue Jay has acknowledged this reply
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Coyote
Member (Idle past 389 days)
Posts: 6117
Joined: 01-12-2008


Message 53 of 450 (540324)
12-23-2009 8:18 PM
Reply to: Message 52 by Blue Jay
12-23-2009 7:57 PM


Re: Off-handed dismissal
In replying to HBD, above, Bluejay writes:

quote:
This makes me a bit curious: what makes the dismissal of baraminology by mainstream science seem off-handed to you?

Well, there are a couple of reasons science might dismiss baraminology. You mentioned one in your post. But here's another, from my post #42, above:

Frair, a baraminologist, provides us with a series of taxonomic guidelines for polybaramins, apobaramins, monobaramins and holobaramins. And what is the most important guideline?

quote:
1. Scripture claims (used in baraminology but not in discontinuity systematics). This has priority over all other considerations. For example humans are a separate holobaramin because they separately were created (Genesis 1 and 2).

This "guideline" shows clearly that this whole baraminology business is religion! It is designed to sound like science, presumably in hopes of fooling the unwary, and it is designed to provide a scientific-sounding bunch of names and a scientific guise for the biblical "kinds" -- but it is not designed to advance scientific knowledge. In fact, baraminology, creation "science," and creationism are all inherently anti-science.

So perhaps that has something to do with the "off-handed dismissal" of this entire endeavor by science.

Edited by Coyote, : Grammar


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

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 Message 52 by Blue Jay, posted 12-23-2009 7:57 PM Blue Jay has acknowledged this reply

  
Dr Jack
Member (Idle past 388 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 54 of 450 (540354)
12-24-2009 6:06 AM
Reply to: Message 49 by herebedragons
12-23-2009 10:17 AM


Re: Baraminology
I am not trying to build a case in favor of Bariminology, but I do question the seemingly off-handed dismissal of anything that goes against mainstream science. So many scientific breakthroughs were based on concepts that went against “conventional” thought.

Maybe, although the extent to which science has been advanced by unconventional thought is vastly exagerated, but in every case the area of investigation has been led forward by the evidence. Bariminology, like the rest of Creation Science, does the reverse: it starts with an idea from a position that stands in complete opposition to all empirical knowledge and then starts investigating.

Scientific ideas of populations, clades, and species (ill defined as that concept is) have grown out of empirical investigations of reality; and they've continually tried to form ideas that reflect a natural classification of organisms.

The baramin, as an idea, has no basis in empiricism. The set of organisms you can connect by successful hybridisations does not have any clear link with any kind of natural classification. That's why scientists don't take it seriously.


This message is a reply to:
 Message 49 by herebedragons, posted 12-23-2009 10:17 AM herebedragons has acknowledged this reply

  
herebedragons
Member (Idle past 15 days)
Posts: 1513
From: Michigan
Joined: 11-22-2009


Message 55 of 450 (540358)
12-24-2009 7:39 AM
Reply to: Message 52 by Blue Jay
12-23-2009 7:57 PM


Re: Off-handed dismissal
This makes me a bit curious: what makes the dismissal of baraminology by mainstream science seem off-handed to you?

It seemed off-handed before your's and coyote's explainations. I should have said 'did' instead of 'do'. I do not really hope or expect that their work will have any real impact - partially because I think they are traveling down a dead end, or at least an end that has no hope of being resolved satisfactorily. And partially because I don't think it is actually a necessary or practical pursuit. I mean, even if they do succeed in establishing "biblical kinds", then what? They are going to jump up and declare "See I told you they could fit on the ark!" Not really a huge step forward.

I did comment that regardless of their findings, the results would be rejected - not based on the data, but based on the fact that their research was religiously inspired. I also commented that they feel they have reasons that at least in my feable, little mind are as "empirical" as persuing abiogenesis.

What do you think of that reason? Is it not a good reason to dismiss an idea? Why?

It kinda seems like "If it ain't broke, don't fix it." On one hand it prevents one from following every individual hair-brained scheme and pipe dream that can possily be imagined (and there have been many such foolish notions throughout history - like the spaceship that was in the tail of Haley's Comet and was coming to take the Space Brothers home). On the other hand, we regularly pursue ideas that have no empirical evidence (like abiogenesis and life on other planets). So I suppose you have to weigh the amount effort with the potential value of the results and determine if it's worth pursuing.

As far as Bariminology goes, I too dismiss it as little more than wishful thinking (effort vs. value) and will just let history be the judge. I would think they could find better ways to spend their money. But, anyway, I am satisfied with your answers. At this point, I am more concerned about defining species and speciation.

Thanks


This message is a reply to:
 Message 52 by Blue Jay, posted 12-23-2009 7:57 PM Blue Jay has responded

Replies to this message:
 Message 56 by Blue Jay, posted 12-24-2009 3:14 PM herebedragons has acknowledged this reply

  
Blue Jay
Member (Idle past 981 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 56 of 450 (540386)
12-24-2009 3:14 PM
Reply to: Message 55 by herebedragons
12-24-2009 7:39 AM


Re: Off-handed dismissal
Hi, Herebedragons.

HBD writes:

I do not really hope or expect that their work will have any real impact - partially because I think they are traveling down a dead end, or at least an end that has no hope of being resolved satisfactorily. And partially because I don't think it is actually a necessary or practical pursuit. I mean, even if they do succeed in establishing "biblical kinds", then what? They are going to jump up and declare "See I told you they could fit on the ark!" Not really a huge step forward.

I suspected that we didn't really disagree about this. Otherwise my arguments might have been more aggressive.

Anyway, it's always nice to discuss things with a Christian who's willing to think empirically.

-----

HBD writes:

I did comment that regardless of their findings, the results would be rejected - not based on the data, but based on the fact that their research was religiously inspired.

That's always a concern, isn't it? But, there is a sort of basic sensibility in becoming ideological about something that's extremely well supported by evidence, isn't there? It's not purely logical, per se, but it does make sense, yeah?

Nevertheless, Coyote's complaints are justified: non-empirical belief is never a good foundation on which to base a line of scientific inquiry.

-----

HBD writes:

I also commented that they feel they have reasons that at least in my feable, little mind are as "empirical" as persuing abiogenesis.

This is exactly what I already commented on. The available evidence suggests that life becomes simpler the further back in time we look. If all the evidence we have suggests decreasing complexity as we go further back in time, parsimony tells us that life predating the earliest, simplest life we know will be even simpler. That's the general principle we derive from a simple view of the available evidence.

But, baraminology wants to defy that general principle. Don't get me wrong: there's nothing wrong with defying general principles... but you need some evidence that nature defies the principle before you propose that it does.

I would be interested in discussing what empirical evidence you think there is that the general principle of increasing simplicity the further we go back in time is not universal, but perhaps it would be a better topic for The Grand Theory of Life or Species/Kinds (for Peg...and others). See you there?

-----

Anyway, I look forward to your response. Merry Christmas!


-Bluejay (a.k.a. Mantis, Thylacosmilus)

Darwin loves you.


This message is a reply to:
 Message 55 by herebedragons, posted 12-24-2009 7:39 AM herebedragons has acknowledged this reply

  
RAZD
Member
Posts: 20154
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.1


Message 57 of 450 (540778)
12-29-2009 1:12 AM
Reply to: Message 35 by herebedragons
12-21-2009 12:23 PM


Re: for herebedragons - speciation, definition first, discussion second
Hi herebedragons, sorry to take so long getting back to you.

I also found several other threads on similar subjects and have read through them.

Good idea, hope they were helpful.

First of all, I see defining a species is very subjective and difficult to nail down precisely, since there is no one "perfect" rule to apply.

Indeed, and this should be your first clue that the diversity of life is due to natural development over time -- each breeding population can be organized by cladistical methodology into a bush-like pattern quite easily, but the definition of species that applies to one such pattern cannot always be applied to another. The cladistical pattern is why it seems that a definition should be easy, the reality is that things are never as simple as they first appear.

It seems to me that it is important define species accurately and with a fair amount of precision.

No, the only definition that matters is how the organisms see themselves -- who are potential mates and who are not -- and how their behavior differs towards potential mates compared to not potential mates. Competition vs cooperation.

Take the ring species the asian Greenish Warbler:

quote:
Greenish warblers (Phylloscopus trochiloides) inhabit forests across much of northern and central Asia. In central Siberia, two distinct forms of greenish warbler coexist without interbreeding, and therefore these forms can be considered distinct species. The two forms are connected by a long chain of populations encircling the Tibetan Plateau to the south, and traits change gradually through this ring of populations. There is no place where there is an obvious species boundary along the southern side of the ring. Hence the two distinct 'species' in Siberia are apparently connected by gene flow. By studying geographic variation in the ring of populations, we can study how speciation has occurred. This unusual situation has been termed a 'circular overlap' or 'ring species'. There are very few known examples of ring species.

It becomes rather obvious that no definition of species will be able to delineate where in the ring the west Siberian greenish warblers (P. t. viridanus) and the east Siberian greenish warblers (P. t. plumbeitarsus) become different species, and yet in the area of overlap they behave as different species behave, they no longer see the other variety as potential mates and behave as though they are different species.

Yet what occurs there, breeding isolation, is all that is necessary for diversification of life forms to occur - for breeding populations to divide into discreet groups when before they were all one group sharing genetic hereditary traits.

What is important for biological diversification is that breeding isolation occurs, and then once that happens you have two (or more) populations able to evolve in different ways, along different paths, in different ecologies. Without this mechanism there would only be as many distinct breeding populations as there were original life forms, and horses could breed with donkeys and zebras and they would produce viable offspring.

Speciation is what is important, not the definition of species.

I wasn't sure what you were meaning by this (the {ramble} part made it confusing what your intention was), but yeah, maybe in some ways it would be more accurate to classify organisms that way, although the amount of work involved would certainly not make it "easier". And, as you pointed out, it still comes down to subjectivity - "how much needs to be the same and how much needs to be different?"

You can develop any number of subjective definitions for species, and in the end you will have similar difficulties in making them apply. Consider the genetic similarity definition and the ring species: if your genetic similarity restricts the species to one variety plus each neighboring variety (because they do interbreed), then you still have the problem with defining where the separation occurs.

This hasn't been done? Kinda surprising that it hasn't.

Why? Once it becomes apparent that any definition is subject to problems and cannot resolve all classification issues, then it becomes less important to make a definition that you know is problematical when you can use the current one, while knowing that it doesn't apply all the time.

Not that this is definitively wrong, we need to be able to categorize them in some way - in the best way we know how.

The only reason we need to classify them is so we can classify them. Organisms don't care what classification they belong to.

So far, the best methodology known is to use cladistic analysis, using as many hereditary features as possible to evaluate the hereditary relationships.

Taking the rings species above and subjecting it to cladistic analysis shows an ancestral population dividing into the six known varieties, with one of the southern varieties likely being closest to the ancestral population:

quote:
Genetic data show a pattern very similar to the pattern of variation in plumage and songs. The two northern forms viridanus and plumbeitarsus are highly distinct genetically, but there is a gradient in genetic characteristics through the southern ring of populations. All of these patterns are consistent with the hypothesis, first proposed by Ticehurst (1938), that greenish warblers were once confined to the southern portion of their range and then expanded northward along two pathways, evolving differences as they moved north. When the two expanding fronts met in central Siberia, they were different enough that they do not interbreed.

Thus there is clear hereditary relationships involved, even though the "species question" appears to be problematical. There is also sufficient difference at the far ends of the ring that speciation, in effect, has occurred: the area of overlap does not include the intermediate varieties that provide interbreeding and so the two ends are reproductively isolated. Gene flow could still occur theoretically, but it has to go the long way around the plateau, and it has to travel through many generations in the process, and it is subject to natural selection along the way, for suitability to each individual variety in its habitat - so it is unlikely that any traits will pass from one end to the other.

But there are just too many unknowns in the fossil record to be certain that species are categorized correctly.

Sorry, but this appears to be wishful thinking, rather than fact. Let's look at Pelycodus:

http://www.don-lindsay-archive.org/creation/pelycodus.html

quote:

The dashed lines show the overall trend. The species at the bottom is Pelycodus ralstoni, but at the top we find two species, Notharctus nunienus and Notharctus venticolus. The two species later became even more distinct, and the descendants of nunienus are now labeled as genus Smilodectes instead of genus Notharctus.

As you look from bottom to top, you will see that each group has some overlap with what came before. There are no major breaks or sudden jumps. And the form of the creatures was changing steadily.


Here you see a breeding population changing over time, with a gradual trend towards larger individuals, from P.ralstoni to P.jarrovii, and then a division into two discreet populations with a gap between them thus demonstrating reproductive isolation has occurred in this fossil record.

You also see a couple of "arbitrary" species designations from P.ralstoni to P.jarrovii, which are based on a subjective analysis of the accumulated morphological hereditary trait changes along the way.

For example, the marsupial flying squirrel and the placental squirrel example you gave me. If fossils were found of these animals they would most likely be considered very similar animals.

Actually I doubt that they would be regarded as similar at all -- the overwhelming fossil evidence would peg the sugar glider as a marsupial and the flying squirrel as a mammal. The skin, being soft tissue, would not likely be preserved, and so the only similarity you would see would be in size of the animals. There are patterns in the skull bones and the teeth that make such distinction quite easy to determine, and you would likely be surprised at the detail of knowledge that scientists have accumulated in their study of the morphology of organisms.

Like wise the Tasmanian wolf and common grey wolf would be thought to be very close cousins.

Or the tasmanian tiger and the indian tiger? Names do not make animals similar.

Again, there are distinct bone structures that rule out this possibility. We had a previous thread that actually went into these differences (Marsupial evolution, unfortunately the pictures for Message 16 are no longer posted). Mr. Jack addresses this issue briefly in Message 36.

Similarly, if fossils for a Saint Bernard and a Chihuahua were found they would certainly be classified as quite unrelated, however we know them to be of the same species. (maybe Saint Bernard and Chihuahua aren't great examples because I can't imagine them actually breeding in the wild - or in captivity for that matter )

Again, there are bone patterns that would place them as related, and closer than either to the thylacine (tasmanian wolf). With fossil evidence of intermediate dogs the case could be made for a ring species. Curiously, some people think dogs do comprise a ring species.

I see you are a fan of cladistic classification. Doesn't this system assume common ancestry? What I mean is you may have sufficient evidence that a horse and a zebra have a common ancestor, but is there that degree of certainty for all known species. Where would you put species that were uncertain? Would they be left out or placed in an approximate or assumed clade? Would it be noted that they were uncertain until sufficient evidence was presented? I do need to have a better understanding of cladistics, so I'm not drawing conclusions, just questioning.

Generally dotted lines are used to denote uncertainty. The interesting thing about cladistics is that the results can often be arranged in a couple of different ways in detail, depending on what evidence is emphasized, but that the broad picture remains the same. The analysis then shifts to a most parsimonious explanation to decide which is most likely. These different patterns are published and available for others to review, just as is done in most of science when conclusions are tentative.

A newer system of classification I found some information on is Baraminology. You probably have already looked at it and drawn your own conclusions but here is the link:
http://www.christiananswers.net/q-crs/baraminology.html
It is a system of classification that some are trying to develop. It is highly criticized and considered to be junk science.

My prediction is that baraminology done with an open mind will result in the same relationships as have already been determined from morphological analysis, genetics and cladistics (and which agree with each other for most of the patterns known in science).

gives some degree of confidence that they are willing to base their conclusions on the data and not pre-conceived notions (whether they do what they say is another matter).

The institute of creation research requires adherence to the following preconceived notions:

http://www.creationresearch.org/hisaims.htm

quote:
A number of principles were established from the beginning. First, members of the Society, which include research scientists from various fields of scientific accomplishment, are committed to full belief in the Biblical record of creation and early history. Thus, they advocate the concept of special creation (as opposed to evolution), both of the universe and of the earth with its complexity of living forms. All members must subscribe to the following statement of belief:

1. The Bible is the written Word of God, and because it is inspired throughout, all its assertions are historically and scientifically true in the original autographs. To the student of nature this means that the account of origins in Genesis is a factual presentation of simple historical truths.
2. All basic types of living things, including man, were made by direct creative acts of God during the Creation Week described in Genesis. Whatever biological changes have occurred since Creation Week have accomplished only changes within the original created kinds.
3. The great flood described in Genesis, commonly referred to as the Noachian Flood, was an historic event worldwide in its extent and effect.


bold underline for emphasis. Sorry. Up to their eyeballs in preconceptions.

Their research has confirmed equid fossil series is a legitimate example of species evolution. This is a series that creationists have long been critical of.

Congratulations: their research found they could no longer deny the equid series was what scientists had claimed for decades. Should I repeat my prediction?

The problem is that he interprets both cases as post-flood diversification.

Which is a preconception.

First of all, I personally am not convinced that the bible really says that the flood occurred <6000 years ago, but that is the position of most creationists. But that too is a different discussion.

An entirely different discussion, one that has been discussed on other threads, and not one creationist has been able to provide any objective evidence for a world wide flood at that time. Evolution and geography have been able to show continuous growth patterns for much longer.

And secondly, the possible explanation for the rapid transformation of C3 to C4 photosynthesis that was presented was that the information for the C4 pathway was already contained in the DNA code and was turned on like a switch by some stimulus. This makes much more sense to me personally than gradualism. I would like to discuss this idea a bit later.

This too deserves a new thread.

A mechanism for Darwin's theories was not known for what, 50 years after his publication of Origin of Species, when DNA was discovered. Yet his theories weren't arbitrarily thrown out.

The mechanism for creating variations in a breeding population were not known, but the existence of variation was.

The mechanism of natural selection that Darwin proposed only needed to have variation occur to provide the results.

Variation plus selection is what results in evolution, the change in proportions of the hereditary traits in breeding populations from one generation to the next.

Enjoy.

Edited by RAZD, : more


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This message is a reply to:
 Message 35 by herebedragons, posted 12-21-2009 12:23 PM herebedragons has responded

Replies to this message:
 Message 59 by herebedragons, posted 12-29-2009 2:14 PM RAZD has responded

  
herebedragons
Member (Idle past 15 days)
Posts: 1513
From: Michigan
Joined: 11-22-2009


Message 58 of 450 (540803)
12-29-2009 9:48 AM
Reply to: Message 51 by Dr Jack
12-23-2009 11:32 AM


Speciation
Thanks, Mr Jack.

I wrote a longer post about this in a another thread: The problem of species

I actually had already that post and it did influence my thinking on later posts.


This message is a reply to:
 Message 51 by Dr Jack, posted 12-23-2009 11:32 AM Dr Jack has not yet responded

  
herebedragons
Member (Idle past 15 days)
Posts: 1513
From: Michigan
Joined: 11-22-2009


Message 59 of 450 (540853)
12-29-2009 2:14 PM
Reply to: Message 57 by RAZD
12-29-2009 1:12 AM


Speciation discussion
Hi Razd

sorry to take so long getting back to you.

No problem at all. I have limited time to spend on this and take the time to think through and research the subject and not just answer off the cuff, so it sometimes takes me a while to reply too. I also think I read somewhere that you are going through chemo? So understandable that it would take a while for you to respond.

In response to my comment on the fossil record, you wrote:

Sorry, but this appears to be wishful thinking, rather than fact.

Not as much wishful thinking as it is my observation at this time. The main reason I joined this forum is to learn about the reasons that scientists accept evolution. I am taking it "step-by-step" and as I learn more about the facts, I am sure I will view many things differently. I am trying to have an open mind, and come to my own conclusions based on what I learn. Because much of our understanding of the fossil record is based on what we know from observation of the present, at this time, I am trying to focus on learning what we actually know from observation of the present.

The only reason we need to classify them is so we can classify them. Organisms don't care what classification they belong to.

This is more the understanding I have in a later post, after reading other threads and some other materials.

Speciation is what is important, not the definition of species.

While I understand what you're saying that speciation happens regardless of how we define "species", the vagueness of the definition is still causing mesome confusion. Here are some examples:

I found examples of Agapornis (Love Birds) that can hybridize across three levels of the polygenetic tree. I realize that the examples happen primarily in captivity, rather than in the wild. But it is still a bit confusing as to why after speciating three times they are still closely related enough to produce viable offspring.

Another example is the greenish warblers. My thinking about this situation goes something like this ... Let's call the original population species 'A'. And each variation around the ring is represented by '1' with the eastern group being '+' and the western group being '-' (to indicate variation is going in different directions). So, the next group to the east would be A(+1) and the next group to the west would be A(-1) and so on until we have, say A(+3) and A(-3), which due to variations in song (language), plumage (physical appearance) and behavior (social factors) they no longer see each other as breeding partners. As you pointed out, there is no place around the ring where it can determined a species 'B' has seperated from the original 'A'. And then there is the questions like what about A(+1) and A(-1) or A(+1) and A(+3) are they seperate species? And so on ...
I liken this to the reason I did not choose a wife that lived in, for example, China. We speak different languages, I may not be attracted to their physical appearance, and they have different cultural and social behaviors. While we are geographically seperated, we have the potential to interbreed - I could hop on a plane, meet someone over the internet or whatever, but I didn't. So, I guess I am not overly impressed with the example of Greenish Warblers as an example of speciation.
What I can appreciate is the potential for the Western Warblers and the Eastern Warblers to evolve in different directions (as they already have to some extent) and develop into distinct species. But where they go from here is unknown as of now. So again it's back to ...

The only reason we need to classify them is so we can classify them. Organisms don't care what classification they belong to.

What I would be interested in learning more about is a mosquito that has developed a variation in it's sexorgans that will not allow it to mate with it's parent population. I couldn't remember what the name of it was nor where I saw reference to it.

In reference to DNA testing of horses / donkeys:

This hasn't been done? Kinda surprising that it hasn't.

Why?

I am curious about that because horses and donkeys have different chromosome numbers and I would be interested as to what the explaination for that is (how did donkeys lose chromosones - or horses gain - not sure which way it happened).

Finally, could you give me a source where I could easily find cladistic and/or polygenetic trees so I could better understand the heritage of organisms? I think it would help me understand the development of chichlids, another common example of speciation, and the horse / donkey / zebra example.

Well, that's all for now. Take care.

Thanks


This message is a reply to:
 Message 57 by RAZD, posted 12-29-2009 1:12 AM RAZD has responded

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New Cat's Eye
Inactive Member


Message 60 of 450 (540856)
12-29-2009 2:33 PM
Reply to: Message 59 by herebedragons
12-29-2009 2:14 PM


Re: Speciation discussion
What I would be interested in learning more about is a mosquito that has developed a variation in it's sexorgans that will not allow it to mate with it's parent population. I couldn't remember what the name of it was nor where I saw reference to it.

This made me recall another example that you might be interested in reading about.

In short, there was a species of snail where the ones with right-handed spiralled shells were physically unable to mate with another with a left-handed spiralled shells. Scientists figured out that the handedness of the sprial came down to one gene and they could control it. I think they artificially caused a speciation even by genetically engineering a bunch of left-handed ones, or something like that....

you can read about it here:

http://findarticles.com/...s/mi_m1200/is_16_164/ai_110459320

and here:

http://www.springerlink.com/content/7544p2781l78n437/

The main reason I joined this forum is to learn about the reasons that scientists accept evolution.

This is a great site:

http://www.talkorigins.org/faqs/comdesc/


This message is a reply to:
 Message 59 by herebedragons, posted 12-29-2009 2:14 PM herebedragons has not yet responded

  
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