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Evolution in action? African fish could be providing rare example of forming two separate species
Cornell University ^ | 01 June 2006 | Sara Ball

Posted on 06/02/2006 11:35:07 AM PDT by PatrickHenry

Avoiding quicksand along the banks of the Ivindo River in Gabon, Cornell neurobiologists armed with oscilloscopes search for shapes and patterns of electricity created by fish in the water.

They know from their previous research that the various groups of local electric fish have different DNA, different communication patterns and won't mate with each other. However, they now have found a case where two types of electric signals come from fish that have the same DNA.

The researchers' conclusion: The fish appear to be on the verge of forming two separate species.

"We think we are seeing evolution in action," said Matt Arnegard, a neurobiology postdoctoral researcher in the laboratory of Carl Hopkins, Cornell professor of neurobiology and behavior, who has been recording electric fish in Gabon since the 1970s.

The research, published in the June issue of the Journal of Experimental Biology, describes how some of these fish violate an otherwise regular pattern of mating behavior, and so could be living examples of a species of fish diverging into separate species.


Although these fish look alike and have the same DNA genetic makeup, they have very different electrical signals and will only mate with fish that produce the same signals. Cornell researchers believe that these different electrical signals are the fishes' first step in diverging into separate species.

The electric fish -- known as mormyrids -- emit weak electric fields from a batterylike organ in their tails to sense their surroundings and communicate with other fish. Each species of mormyrid gives off a single characteristic electric impulse resulting in the flash of signals, indicating, for example, aggression, courtship and fear. While the fish may be able to understand other species' impulses, said Arnegard, "They seem to only choose to mate with other fish having the same signature waveform as their own."

Except for some, Arnegard has discovered.

When he joined Hopkins' lab, the team was about to publish descriptions of two separate species. But when Arnegard decided to take a genetic look at these particular fish, he couldn't find any differences in their DNA sequences.

"These fish have different signals and different appearances, so we were surprised to find no detectable variation in the genetic markers we studied," Arnegard said.

Because all of the 20 or so species of mormyrid have distinct electric signals, Arnegard believes the different impulses of the fish he studies might be their first step in diverging into different species.

"This might be a snapshot of evolution," Arnegard said.

Understanding how animals become different species, a process known as speciation, is a major concern in understanding evolution. Arnegard's fish may allow researchers to test if a specific type of speciation is possible.

One common type of speciation is geographically dependent. Animals diverge into separate species because they become physically isolated from each other. Eventually, genes within each group mutate so that the groups can no longer be considered to be of the same species.

Another type of speciation, which many scientists have found harder to imagine, involves animals that live in the same geographic location but, for some reason, begin to mate selectively and form distinct groups and, ultimately, separate species. This so-called sympatric speciation is more controversial because there have been few accepted examples of it to date.

"Many scientists claim it's not feasible," Arnegard said. "But it could be a detection problem because speciation occurs over so many generations." These Gabon fishes' impulses, however, can change very quickly in comparison. So Arnegard suspects that the different shapes of the electric impulses from these mormyrids might be a first step in sympatric speciation.

One the other hand, the fish could be a single species. "This could be just a polymorphism, like eye color in humans, that violates the fishes' general evolutionary pattern but doesn't give rise to separate species," said Arnegard, who will return to Gabon in June to conduct further tests, funded by the National Geographic Society.


TOPICS:
KEYWORDS: crevolist; ignoranceisstrength; pavlovian; speciation; usualsuspects
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To: metmom
Definitions that are not dictionary definitions but *definitions as scientists use them* that are not found in the dictionaries I've checked online.

I did not claim that the definitions as scientists use them are not found in dictionaries. You are either misinterpreting or misrepresenting my statement.

I am referring to situations where words used by scientists have multiple definitions in a dictionary. In such cases, only one definition applies in the context used by scientists. It is neither logical nor honest to argue against a statenent by switching the definition of a word with another definition also found in the dictionary.

This is almost as bad as sending people to Wikipedia to back up your statements.

I provided a reference to an online dictionary that employs definitions from several respected and frequently referenced real-world dictionaries to support my original statement regarding the meaning of the word "validation". It was tgambill who referenced Wikipedia regarding the definition of the word.
661 posted on 06/19/2006 6:25:48 AM PDT by Dimensio (http://angryflower.com/bobsqu.gif <-- required reading before you use your next apostrophe!)
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To: taxesareforever
I never said you didn't make a claim of randomness.

This does not answer my question. Why do you expect that I would have an answer for a case that I do not make?

Matter of fact everything you espouse is randomness.

This also does not answer my question.
662 posted on 06/19/2006 6:32:50 AM PDT by Dimensio (http://angryflower.com/bobsqu.gif <-- required reading before you use your next apostrophe!)
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To: taxesareforever
All processes are of Intelligent Design.

Please support this claim with evidence.
663 posted on 06/19/2006 6:33:14 AM PDT by Dimensio (http://angryflower.com/bobsqu.gif <-- required reading before you use your next apostrophe!)
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To: Dimensio
Are you saying that it is hypothetically possible to observe an event of order coming from non-order and determine that no intelligence is involved, and if so, how would this determination be made?

No, I'm not stating that, you are. You're the one who keeps stating that order can arise from non-order with no apparent intelligent design. Since that's your position, it's up to you to tell me how the determination that no intelligence is involved is made.

664 posted on 06/19/2006 7:11:31 AM PDT by metmom (Welfare was never meant to be a career choice.)
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To: Dimensio
My request is consistent with the requirements of the scientific method; in that respect, it is certainly not "odd".

Which raises a question... What exactly is your scientific background or credentials? Since you seem to be such an expert, always correcting people and challenging them to provide evidence, you must have some of some kind in order to evaluate correctly whether or not their evidence is valid or not.

665 posted on 06/19/2006 7:15:29 AM PDT by metmom (Welfare was never meant to be a career choice.)
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To: Dimensio; taxesareforever
taxes:All processes are of Intelligent Design.

dim: Please support this claim with evidence.

And please support the claim that all processes, or even some, are evidence of no intelligent design.

666 posted on 06/19/2006 7:17:59 AM PDT by metmom (Welfare was never meant to be a career choice.)
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To: metmom
No, I'm not stating that, you are.

Then you acknowledge that your claim is non-falsifiable, meaning that it is not scientific. You have stated that absolutely no possible observation cannot conform to your standard of evidence. If this is the case, then there is no means by which your claim can be evaluated.

You're the one who keeps stating that order can arise from non-order with no apparent intelligent design. Since that's your position, it's up to you to tell me how the determination that no intelligence is involved is made.

You have made a claim that the existence of determinable intelligence bringing order to non-order is evidence that all cases of order to non-order involve intelligence, even when such intelligence is not detectable. That is not a logical position; in order to make that claim, you must be able to define a hypothetical criteria for determining that no intelligence is involved in a order to non-order event. If you cannot do that, then your claim is without any means of evaluation.

You are attempting to claim that because the conditions of some events of order to non-order involve intelligence, all events of order to non-order involve intelligence. You have provided no reason to believe that intelligence must be required in all cases. That intelligence is involved in some cases is not evidence that intelligence is involved in all cases. Your argument is a variant of the hasty generalization fallacy and also the biased sample fallacy. You are claiming that the condition of intelligence behind some events of order from non-order is evidence that all events of order from non-order involve intelligence, even though you acknowledge that it is impossible to determine if no intelligence is involved in such an event. As such, the only samples you accept are samples where intelligence is known. Even if an event occurs where no intelligence is involved, you dismiss it because you have no means of verifying that no intelligence is actually involved. In so doing, it is impossible to determine whether the number of observed events where order arises from non-order without intelligence is zero or non-zero. You are deriving your sample size with a method that rules out any events that do not conform to what you have already concluded. Your argument is not logically valid.
667 posted on 06/19/2006 7:25:35 AM PDT by Dimensio (http://angryflower.com/bobsqu.gif <-- required reading before you use your next apostrophe!)
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To: metmom
And please support the claim that all processes, or even some, are evidence of no intelligent design.

To do this, you must establish a falsification criteria for the claim. If no falsification criteria exists, then the claim cannot be evaluated.
668 posted on 06/19/2006 7:26:44 AM PDT by Dimensio (http://angryflower.com/bobsqu.gif <-- required reading before you use your next apostrophe!)
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To: metmom
What exactly is your scientific background or credentials?

I defer to information written by professionals of natural sciences for scientific information, including the standards of the scientific method.

Since you seem to be such an expert, always correcting people and challenging them to provide evidence, you must have some of some kind in order to evaluate correctly whether or not their evidence is valid or not.

Because I am not an advanced student of any natural science, my evaluation of evidence is limited to verifying that claims of evidence are logically consistent and that claims of scientific explanations satisfy the standards of the scientific method. For example, you have claimed that "intelligent design" is a scientific explanation. If this is true, then you should be able to define a hypothetical falsification criteria for the explanation. Thus far, I have not observed that you have done so. I have also observed that you claim that the existence of some events of order from non-order involve intelligent intervention, that all events of order from non-order involve intelligent intervention. Not only is this the logical fallacy of hasty generalization, but you have also acknowledged that it is not possible to know if any process of order from non-order involves no intelligent intervention, even if no intelligence can be discerned. As a result, the sample from which you have drawn your conclusions is biased, and not valid.
669 posted on 06/19/2006 7:31:03 AM PDT by Dimensio (http://angryflower.com/bobsqu.gif <-- required reading before you use your next apostrophe!)
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To: Dimensio; RunningWolf; metmom; taxesareforever

"The second definition would not. You are attempting "argue by dictionary" by claiming that you are allowed to select one of multiple definitions of a term as a means of disproving a claim. This is not logical; when a word is used in a context, you cannot redefine the word in that context to change the meaning as a valid counterargument."

**** Well, actually it is logical. Your examples are non-secuiter and certainly not cuter. The way you can tell is that the heat of the meat is equal to the temperature in the kitchen with the stove as the source of the heat. So, the meat would therefore equal the heat inside the stove minus the AC that might be on.

Now A counterargument would be, we are talking about validation and not verification. Validation has a meaning of many different kinds. I chose to accept the second one, as this applies to the theory of validation. Otherwise unless you specify which definition that you are referring. I am in fact allowed, as this is the example that I'm using and referring too.

Now, the first definition, and I quote:."

"In general, validation is the process of checking if something satisfies a certain criterion."

Which in fact Evolution does not, simply because there has not been one example save the fruity flies or whatever, and the fact those species thought evolved still exist today...... The second definition,

"To declare or make legally valid, to prove valid or confirm the validity of data, information or processes."

Now we are getting somewhere to the context that you were referring to. Therefore your assertion is incorrect as usual. So, as a caveat, if you refer to the definition(S), we are not talking about software, computer security, manufacturing, we are talking about validating a "theory" which I can't really bring myself to call, scientific, but a fabrication that is elaborate, I will have to admit. An "expert" in the theory of Evolution, is just that. An expert in ToE, but, in a flawed theory, he or she is a has flawed arguments and ill gotten facts that use as proofs for naught.......


670 posted on 06/19/2006 7:44:47 AM PDT by tgambill (I would like to comment.....)
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To: Dimensio

"While you are entitled to your opinion, your opinions regarding my character do not define reality. As such, it is possible for your opinions regarding my character to be wrong."

*****very interesting assertion, being it is non-secuiter to the discussion at hand. I made no opinion to your character. It appears that you are fabricating your posts from no factual evidence. You are inferring that these statements are referring to "your character"? You are completely incorrect in your assertion and assumptions. You seem to be taking points of contention in a personal way, which would mean that you may have do some inter-reflection to find out why you are feeling personally, confronted....




"Why am I incorrect? Please provide evidence to support your claim."

****You have the answer for why you share a different opinion, why do you share a different opinion? Please explain....




"Your analogy does not actually support your claim. You are elaborating on your previous claim regarding my character; elaboration is not evidence."

***** This statement is certainly invalid in that as I explained no one has said anything about your character. This is a feeling or whatever, you have acquired on your own. Therefore this statemment is invalid and does not apply.



"Again, you are elaborating on your previous claim. You have thus far not provided evidence to show that your claims regarding the nature of my responses are accurate."

***** Your preceding quote is another example of using disinformation techniques. One is to present questions whereas the answer is obvious, unless the question or request is submitted for some other reason. Evidence are self evident in the posting.



"Incorrect. I only ask that arguments be backed up with logically consistent supporting evidence. I do not believe such a request to be unreasonable. You have again provided no evidence to support your claims regarding my responses. Asserting that my responses fit a certain pattern does not demonstrate that my responses actually fit said pattern."

*****Now, I can go along with this, as you have not required an elaborate response, however, you are always asking for evidence when it's plainly provided. However, I am correct in asserting that this tactic is used by disinformation artist. Since you claim not to be one, then, this would not apply to you. There it is a correct assertion. This is another example of how you are taking these posts personal backing up my previous posts that any of the posts are reflecting on your character. Just another proof that you are taking it all too personal.



"Thus far I have concluded that you are not qualified to speak on the subject of evolution only because of your admission that you believe study of the theory is a "waste of time" and that as such your knowledge of the subject is deficient. It is on that basis -- your admission that you know little of the theory -- that I have derived my conclusion that you are not credible. I do not expect that an individual have the experience or knowledge of a professor of the subject on which they speak, but I do not believe it unreasonable to expect them to have some knowledge on the subject before they claim to make credible, authoritative statements."

****** This is, I'm afraid to say it.....typical of disinformation tactics. First, you can't declare that someone is credible or not. You have proven that your credibility is questionable due to taking the posts as personal We should get back to the discussion at hand concerning evolution and not this silly bantering that you are persisting with. You ignore the issues and imply they are old charges as if new information is irrelevant to truth. Why do you refuse to address the issues by use of such disinformation tactics? In addition...You completely evade issues and attempt others from daring to attempt it by making it a much bigger mountain than necessary. You eat an elephant one bite at a time. Which brings up an interesting point that an expert like yourself can explain to me.

The genus Trilophodon, (from Greek Triloph: meaning three crested, and odon: meaning tooth, refering to the molar tooth belongs to the family of Mastodons (Mammutidae) and is sometimes called Tetrabelodon or Four tusked Mastodon.

This Trilophodon was about 5 m long and 2.5 m high, if I understand correctly, and had four parallel tusks (two on the top jaw, two smaller ones on the bottom jaw) and lived from the Miocene epoch (26 million years ago) to the Pleistocene epoch (2 million years ago) in Europe, Eurasia, Africa, and North America. So, if it became extinct as the books say, when did they start evolving....? I mean has an elephant always been an elephant, or was an elephant ever a fish or whale or whatever.



"I provide an explanation when I disagree with a given point, and I have cited sources on more than one occasion. If you feel that I have inadequately justified any statement, then identify that statement or statements and I will provide further detail and relevant references. Merely asserting that I engage in such behavior is not evidence that I engage in such behavior."

*****Well, not see there you go again....taking it personal. Your behavior is fine, in my opinion and you appear to have good character. So, I wouldn't take things so personal.




"I'm not going to research the exact posts, but this has been the trend.

You are admitting, then, that you are making statements regarding my behavior that you are unwilling to support with evidence. You are acknowledging that you will refuse to substantiate your claims against me."

**** No, you are assuming things and putting words into what doesn't exist. You are also talking off the thread and not about evolution. Didn't refuse, I just don't have the time to repost what has already been posted. Just read back and you as others will see clearly.



"Again, you have provided absolutely no evidence whatsoever regarding your accusations against my character or about my behavior. You have made a long list of claims regarding my postings, but you have not substantiated any one of them with relevant references. I do not believe it unreasonable to request that you reference specific postings where I have made claims that conform to your accusations; as my postings are readily accessable, my request is certainly not a demand for an "impossible proof".

*****The remainder of your posts are irrevelent and off thread. This last one, is an obvious effort by yourself, to make these postings personal or "slams" on your character when I have clearly demonstrated that no such posting has existed. You taking it personal does not make is such......So, I suggest that to save your credibility, we should go back to the theory of evolution and back on track.









671 posted on 06/19/2006 8:44:54 AM PDT by tgambill (I would like to comment.....)
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To: tgambill; Dimensio
Get off of this personal tangent NOW and get back to the issues. Do not pick at the scab.
672 posted on 06/19/2006 8:55:29 AM PDT by Religion Moderator
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To: Religion Moderator
" NOBODY expects the Religion Moderators!

Our chief weapon is suprise...surprise and fear...fear and surprise....
Our two weapons are fear and surprise...and ruthless efficiency....
Our *three* weapons are fear, surprise, and ruthless efficiency...and an almost fanatical devotion to JimRob....
Our *four*...no...
*Amongst* our weapons.... Amongst our weaponry...are such elements as fear, surprise....

I'll come in again."


= )
673 posted on 06/19/2006 12:17:52 PM PDT by Hoplite
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To: Hoplite

LOLOL!


674 posted on 06/19/2006 12:22:55 PM PDT by Religion Moderator
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To: Dimensio
My request is consistent with the requirements of the scientific method; in that respect, it is certainly not "odd".

Your statement would make sense if amended to read...

My request is consistent with the requirements of Popper's (or whoever's) philosophy of science; in that respect, it is certainly not "odd"

Popper's (or Feyerabend's or Kuhn's or whoever's) opinions on the philosophy of science are not synonymous with "science" or "the scientific method". You'll be less confused if you draw this distinction.

I am asking metmom to show that the claim is meaningful by presenting a hypothetical example that, if observed, would show the claim to be false.

Can't you understand the meaning of it by reading it?

675 posted on 06/19/2006 5:43:22 PM PDT by Ethan Clive Osgoode
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To: Dimensio
Why do you expect that I would have an answer for a case that I do not make?

Sounds to me like you are opposed to any dialogue to which you don't have an answer for. Typical.

676 posted on 06/19/2006 5:57:55 PM PDT by taxesareforever (Never forget Matt Maupin)
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To: Dimensio
For example, you have claimed that "intelligent design" is a scientific explanation. If this is true, then you should be able to define a hypothetical falsification criteria for the explanation.

And you have claimed that evolution is a scientific explanation. If this is true, then you should be able to define a hypothetical falsification criteria for the explanation.

677 posted on 06/19/2006 6:02:25 PM PDT by taxesareforever (Never forget Matt Maupin)
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To: taxesareforever
If this is true, then you should be able to define a hypothetical falsification criteria for the explanation.

Does the name "Behe" and "Irreducible complexity" ring any bells?

Irreducible complexity is a candidate for the falsification of the ToE, but to this day hasn't proven up to the task, as the proffered examples have been investigated more fully and evolutionary paths discovered.

Alternately, the discovery of evidence which didn't fit the evolutionary path established thus far would prove problematic for the ToE, hence the "Dinosaur & Man footprints" Paluxy controversy in Texas.

678 posted on 06/19/2006 7:12:48 PM PDT by Hoplite
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To: Dimensio
Then you acknowledge that your claim is non-falsifiable, meaning that it is not scientific.

And is philosophy scientific? This claim of falsifiability is a philosophy about science and therefore is not scientific.

And on what basis do you conclude that order can arise from non-order without any intelligent intervention? What scientific basis is there for this assertion? Please provide support for your position.

679 posted on 06/19/2006 7:49:26 PM PDT by metmom (Welfare was never meant to be a career choice.)
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To: Dimensio
To do this, you must establish a falsification criteria for the claim. If no falsification criteria exists, then the claim cannot be evaluated.

No, your turn. You disprove it. You've been asked to provide support for your statements and you have not. You can at least return the courtesy to others that you demand of them. Otherwise it would be reasonable to conclude that your lack of response, and answer, and support of your positions, indicates that there is none. That it either cannot be done or that you are incapable of doing it.

Since you cannot provide examples, supported by anything, that order can arise from non-order without intelligent intervention, then it can be reasonably concluded that no such examples exist and there is no basis for coming to that conclusion. Deciding that something happens with no basis for it is irrational. It is not scientific to come to any conclusions with no evidence to support it.

680 posted on 06/19/2006 7:59:25 PM PDT by metmom (Welfare was never meant to be a career choice.)
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