DNA differences between rivers

[OTp1144]

Not sure if anyone has seen this before, but I came across it in some browsing of the interwebs. I thought it was a good read, if brief, on the genetic differences within species of cichla between different rivers.

http://www.acuteangling.com/Reference/EnglishPoster.html

 

[heatherbeast]

Neat poster. It looks like orinos are homebodies, with individuals and populations having much smaller ranges than temensis. They were able to infer a distance of 100 km can cause differences between populations of orinos, but I wonder if they added more collection points, would that distance shrink even more? Temensis appear to like travelling and mixing amongst themselves, but what was the largest distance between collection points that they were able to measure without seeing that difference (ie, what was the longest distance between collection points at the end of each tributary?) Are they considering expanding collection points to try to find the distance at which variation CAN be detected in temensis?

Also, how many fish did they sample from at each site? Could individual variation account for some of the observed differences? Would they see the same results if they examined a different section of the genome? (I do like that they chose ATPase, it's a pretty important protein that tends to change slowly over time, these are referred to as conserved sequences). Those are all questions that I hope they'll answer once the poster grows into a full-blown research article.

Maybe I'll send my above musings to the email listed on the poster...

 

[BrookKeeper]

I havent yet clicked on the link, but i can tell you already that this is not a unique study among cichla... Take a look at this ridiculousness among darters (I only consider it ridiculous in light of the given nomenclature... I completely respect the identification of unique species).

http://tnaci.blogspot.com/2012/11/new-fishes-named-after-us-leaders-three.html

 

[heatherbeast]

It's not unique to fish, either, trust me. I've seen studies like this among different species of bacteria, which begs the question of /what/ is the appropriate degree of resolution to be able to define a species using molecular methods?

 

[BrookKeeper]

Here is a good read on that very topic as applied to T&E species. The authors are fish people, but the article gives a good history of the issues associated with identifying species. I read the whole thing, but I know most won't...

http://lawschool.unm.edu/nrj/volumes/45/2/06_george_species.pdf