Evolution in action? African fish could be providing rare example of forming two separate species

Cornell University ^ | 01 June 2006 | Sara Ball

[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.

[taxesareforever]

If you think they lead to inconsistencies, go forth and win your Nobel Prize.

I would but they don't award the Nobel Prizes to people who think logically.

[Ethan Clive Osgoode]

I do not believe that natural selection is analagous to such a process.

I'm asking you if these processes are "random" or "nonrandom". We'll get to natural selection a little later.

(a) Is this "random" or "nonrandom": p(A) = p(B) = 0.5?

(b) Is this "random" or "nonrandom": p(A) = 0.3, p(B) = 0.7?

[tgambill]

Okay.....but there seems to be a thin line in what is personal and a subtle slam. So, I'll be a little more careful.

[apackof2]

I have been corrected on subjects in previous discussions

Interesting choice of words

Is this you conceding that you were mistaken?

Please say yes, as there was only one Perfect Person

[Dimensio]

Is this you conceding that you were mistaken?

I do not see it as a concession, as I have never previously suggested or stated that I have never been mistaken in the past. I have, in fact, made mistakes and others have notified me of them.

[Dimensio]

Please be specific and give a number of these cases.

I do not believe that the number of occurances are completely documented. Any instances where crystals formed would be such a case, and not all such occurances have been observed. That is only a fraction of the number of events of order arising from "chaos" without any apparent intervention of intelligence.

[Dimensio]

Which is not the same at all as constantly telling people they are wrong, mistaken, in error, however it's worded about everything they post.

How does this comment relate to the discussion?

[Dimensio]

There is a basis, or precedent, for concluding that order requires intelligance because we see that in the manmade world around us. Everything that was altered from it's natural state by humans had intelligence behind it.

This is true by definition. You have created a tautology.

All the things you are currently surrounded by, were a product of intelligence. Just because the universe and *nature* are *natural* doens't mean that the same concept cannot be applied; that the order and complexity are a result of intelligence. It's not illogical at all to deduce that.

What observations suggest that the universe and the fundamental properties thereof must be a product of intelligence? What hypothetical observation could potentially falsify your conclusion?

[Dimensio]

What is illogical is to deduce that order can arise from non-order, on it's own, with no *mechanism* to produce order. And if there was a mechanism, that in itself would indicate intelligence.

How do you conclude that all mechanisms for causing non-order to become order are a result of intelligence?

There is no basis for assuming that order can arise from non order, or chaos. It is illogical to assume so when there is no basis for it.

Your conclusion is based upon a non-falsifiable assertion. You have ruled out any emergence of order from non-order in a system where no apparent intelligence is involved because it cannot be proved that a non-detectable intelligence is not involved. This means that you effectively rule out the possibility of any evidence that can contradict your claim. As such, you have presented a non-falsifiable claim, which effectively means that your claim is conjecture, and not a valid asessment of reality. If no possible example could ever hypothetically exist to contradict your conclusion, then your conclusion is not scientific.

That's the evidence for intelligent design. It's scientific because it can be observed and reproduced and data can be got from it.

It is not scientific, because you have acknowledged that there is no hypothetical scenario under which your claim could be proved false. You have stated that there is no possible observation that could demonstrate order from non-order without intelligence because it is impossible to rule out non-detectable intelligence. In so doing, you have made your claim impossible to evaluate.

[tgambill]

I'll provide you the references again as they come from the Evolutionist side.

More to come this weekend..........

"All scientific theories are incomplete."

Uhhhh, exactly...so the theory of Evoluion could not possibly be validated.

You wrote:

"Evolution has been validated by multiple independent lines of evidence; most notably, both the fossil record and remnants in the DNA of extant species have created independent lines of evidence suggesting the same conclusions regarding common descent."

**** So, in a round about, double talking manner explain to me how is it that "all theories are incomplete", yet, "evolution has been validated". How can an incomplete theory be validated? I'm just curious.

Post 533

and

"You are simply incorrect. Numerous lines of evidence have "validated" the theory of evolution amongst the community of biologists. Your error apparently lies in your misconception that scientific validation means establishing a claim beyond "a shadow of a doubt". You are mistaken, thus your conclusions are incorrect."

***** I disagree, show me in writing or in reference to published criteria for defining scientific validation, that supports this statement. Your word does not make is so. Otherwise my conclusions are correct. I'm open to being corrected by an independent source.

[Dimensio]

Uhhhh, exactly...so the theory of Evoluion could not possibly be validated.

Your reply does not logically follow. That scientific theories are incomplete does not mean that they cannot be validated. Validation does not mean completion.

So, in a round about, double talking manner explain to me how is it that "all theories are incomplete", yet, "evolution has been validated". How can an incomplete theory be validated? I'm just curious.

Observing events fully consistent with and/or predicted by the theory. Attempting and failing to observe events that the theory predicts can never occur.

I disagree, show me in writing or in reference to published criteria for defining scientific validation, that supports this statement. Your word does not make is so. Otherwise my conclusions are correct. I'm open to being corrected by an independent source.

Empirical validation is a part of the scientific method; it is a required step before a hypothesis may be labelled theory.

[metmom]

Given a lack of information on the subject, the safest assumption is to make no assumptions of extraneous entities.

But by making *no assumptions* you ARE making an assumption. And it's not true that it's the safest assumption to make. It's an assumption reflecting a bias. The *no entities* claim is not neutral so there is no reason for it to be the default option when considering entities or the cause behind something. That's just favoring one point of view over the other and is not acceptable from the scientific viewpoint of true objectivity.

I do not claim to have proved that no intelligence exists behind the order of the universe. I only state that thus far no evidence has been presented to show that intelligence is behind the order of the universe.

Sure the evidence has been presented; several times in the last hundred posts or so. At any time they area available to go back and look at. Refusing to acknowledge it or judge it as not valid, or not real evidence , or whatever, doesn't mean that it hasn't been presented. It's the same for all the Scripture that has been presented. Ignoring it, or deciding that it doesn't fit, or not giving it any credence, doesn't absolve one from the responsibility to answer, especially when that one has asked for evidence.

You are claiming that there can exist no known situation where order occurs without intelligence as a means of ruling out all instances where order occurs without any apparent intelligence.

No, that's not illogical. It's completely logical. There are many cases where we know for sure that there was intelligence behind the order and complexity of objects, whether completely man-made or merely man altered. So it is illogical to presume that there was no intelligence behind the order and complexity where we're not sure. Precedent has been set by the cases we are sure about. There is NO basis of assuming no intelligence in the cases we aren't. So why should we presume that in cases where we aren't sure that there is no intelligence behind it? On what basis does one come to that conclusion?

[metmom]

taxes: Please be specific and give a number of these cases.

dim: I do not believe that the number of occurrences are completely documented. Any instances where crystals formed would be such a case, and not all such occurrences have been observed. That is only a fraction of the number of events of order arising from "chaos" without any apparent intervention of intelligence.

And how is it determined that there is no apparent intelligent intervention? What form would evidence of apparent intelligent intervention take anyway? What would one look for and how would one make that determination? So what are some of these cases?

Any instances where crystals formed would be such a case, and not all such occurrences have been observed.

*all such occurrences have been observed* of what? This statement makes no sense.

So where are the specific several cases and where is the justification to support the claim that there is no apparent intelligent intervention?

[Dimensio]

Sure the evidence has been presented; several times in the last hundred posts or so.

No evidence has been provided. A faulty analogy has been provided, and I have explained why it is faulty.

No, that's not illogical. It's completely logical. There are many cases where we know for sure that there was intelligence behind the order and complexity of objects, whether completely man-made or merely man altered. So it is illogical to presume that there was no intelligence behind the order and complexity where we're not sure.

The problem with your argument is that you have defined a state where it impossible to be sure that no intelligence is behind a change from non-order to order. Because of this, the only two possible states are "intelligence" and "unsure". Even if it is possible for order to arise from non-order without intelligence, it is impossible -- by your standards -- to determine as much. As such, there is no reasonable standard by which "order from non-order requires intelligence" can be evaluated. You have established that no falsification observation can occur, so there is no method for evaluating the likelyhood of your claim. If there is no means to evaluate your claim, then it is not logical to assume your claim to be true.

An analogy is of a bag of some finite but large number of marbles, with two possible colours -- green and blue -- for the marbles and the possibility that only one color is actually present. If marbles are removed at random by a "middleman", who then filters out any non-green marbles, and then presents the filtered result to you, it will be impossible for you to draw any conclusions about the colour proportions of the marbles in the bag. To extend the analogy further, your argument is akin to concluding that only green marbles exist in the bag, even though you acknowledge that you would never be able to observe a blue marble if one were removed from the bag.

[taxesareforever]

I do not believe that the number of occurances are completely documented.

So, you were just making an unsubstantiated statement. No supporting evidence.

[taxesareforever]

Because of this, the only two possible states are "intelligence" and "unsure".

And evos take the stand of "unsure".

[Dimensio]

And how is it determined that there is no apparent intelligent intervention? What form would evidence of apparent intelligent intervention take anyway?

If you wish to assert intelligent intervention, then it is upon you to provide methods by which such intervention may be detected.

[Dimensio]

And evos take the stand of "unsure".

It is more logical, and more honest, to acknowledge an inability to reach a conclusion than it is to invent a conclusion merely to have one, even if no evidence exists to support it.

[Dimensio]

So, you were just making an unsubstantiated statement. No supporting evidence.

I was not. I did not claim to have an exact number of events.

[Hoplite]

Mine.