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

Cornell University ^ | 01 June 2006 | Sara Ball

[PatrickHenry]

Everybody be nice.

[PatrickHenry]

Evolution Ping The List-O-Links

A conservative, pro-evolution science list, now with over 370 names. See the list's explanation, then FReepmail to be added or dropped. To assist beginners: But it's "just a theory", Evo-Troll's Toolkit, and How to argue against a scientific theory.

[Red Badger]

Maybe their batteries are just low...............

[Red Badger]

I picked up an Electric Ray once here on the beach, mistaking it for a plain ray. I was shocked to find out there are Electric Rays here, where they are not supposed to be..............

[Red Badger]

Maybe some of these fish are AC/DC..................The one in the middle looks kinda gay.......

[Squawk 8888]

I'm waiting for the punchline about getting a charge...

[Obadiah]

Aww geeze..not this...again!

[bobdsmith]

shocked huh? (that was deliberate right?)

[Red Badger]

Uhhhhh......yeah..............

[KMJames]

..."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,...

BINGO. We have a winner.

[Coyoteman]

===> Placemarker <===

[RobRoy]

"The fish appear to be on the verge of forming two separate species."
Key word - "appear". As usual, I have no problem with the discoveries, just the conclusions. Often I don't even have a problem with the conclusions, as long as they are not presented as more or less facts themselves.

[Hunble]

I will vote for "polymorphism, like eye color in humans", since the difference is rather minor.

Question: Can electrical impulse patterns be learned, like a language? In addition to basic prey location, it is well known that these electrical pulse patterns are also used for communication.

[AntiGuv]

I will vote for "polymorphism, like eye color in humans", since the difference is rather minor.

Except, of course, that humans of different eye color do not automatically refuse to mate with one another, which makes the fish difference rather major by comparison.

[bobdsmith]

Of course if green eyed humans and brown eyed humans formed seperate populations and didn't interbreed, then they could be considered seperate species.

If in this case you have two distinct populations each with their own features then the case for them being seperate species is stronger.

[Hunble]

Liberal and Conservative humans occasionally interbreed, but they are rapidly diverging into two distinct populations.

It may be interesting to see how this develops in the future. Who knows, humans may diverge into two separate species.

This may become a well documented case of learned behavior creating a genetic divergence of a population.

[BJClinton]

Watt are you talking about?

[KMJames]

...humans of different eye color do not automatically refuse to mate with one another...

But, then we have this...

..."They seem to only choose to mate with other fish having the same signature waveform as their own."

Except for some, Arnegard has discovered...

So, it seems to me that some fish are attracted to others - is there really anything more to this. I'm inclined to stay with the most likely conclusion.

[AmericanRepublican]

Uhhhhhhh...

They're still fish...

...thus...

...they're still delicious.... mmmmm....

[AntiGuv]

Well, I took the "Except for some" to modify "Each species of mormyrid gives off a single characteristic electric impulse" because otherwise "They seem to only choose to mate with other fish having the same signature waveform as their own" is a false statement.

But you make a good point! Something is either poorly written or poorly phrased here.