New Discus named Symphysodon tarzoo

Discussion in 'Discus' started by Len, Mar 3, 2007.

  1. Anonymous
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    Thank you Dirk. Your right that this is very heavy stuff but it's also very interesting.

    Wow, it's very interesting that similar species would have different rates of mutation. It must prove that there are external and well as internal factors that need to be taken into account. Have they noticed this same occurances within different populations?
     
  2. Cameron
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    Cameron Green fingers

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    Thanks for explaining that Dirk, it makes sense. And going a bit off-topic here but a few weeks ago I think we got our wires crossed and I would just like to clear the air about that one as it pertains directly to your quote above. It was concerning the comment I dropped about the outdated Sears and Conlin paper which stated that it is better to not add phosphates to your tank as it contributes to algae issues, and that new studies have shown that that is certainly not the case. Perhaps i worded myself wrong but what I was trying to say is that I would personally go with the new scientific data rather than the old data from that paper. I certainly did not intend to dis science, I absolutely love science and following all the new breakthroughs they are having, I am possibly the least dogmatic person you will ever meet :) I certainly did not not mean to offend you nor your profession. I am pretty much pro-science across the board.

    I completely understand, and even though the paper may well be over my head I'd still be interested in taking a squizz when 'the dust settles' so to speak. Good luck with your research.

    Taking into consideration that Linnaeus was only 28 when he first published 'Systema Naturae' in the 1730's!...the guy was a genius well ahead of his time.

    Just to add to the above for people who don't know, the Rift Lakes in Africa are extremely interesting for Evolutionary biologists to study as they have been completely closed systems for the past few million years and as Dirk states there seems to be only one common ancestor (in fact we *all* have one common ancestor, so therefore I can start calling Dirk uncle Bellstedt :) !) Yet speciation in the lakes has occured at such a rapid pace (relatively speaking) that it makes sense for scientists to study the progress of evolution and speciation here. It really is a remarkable 'slice of nature'.

    So coming back to the Tropheus situation in Lake Tanganyika :) The reason there are so many morphs is due to geographic isolation; huge boulders that come tumbling down from the cliffs manage to separate a particular group, even though the distance may only be 50 metres the fish are so territorial and never stray far away from their 'homes' and as such may never see the other part of their group again. If the 2 groups did manage to reconnect then most likely they would produce fertile offspring as they only would have gone through a few small steps of mutation (micro evolution) and as such is not enough to declare them separate species. If the separation managed to last for another few million years then by this time large changes would have occured (macro evolution) and fertile offspring would not be possible? I know that there's no such thing as Micro or macro evolution, as they are both exactly the same thing. Evolution is evolution, yes?.

    It's freakin awesome to say the least, blows me away :eek:

    Thanks for that Dirk :thumb:

    Work? What's that? :scratch:
     
  3. Andre
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    Andre Green fingers

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    Is this not also true for the P. scalare vs P. altum?  Because the altums occur in the upper reaches of the orinico they are seperated from P. scalare.  It could be remotely possible for the altums to get swept down river into scalare territory, but impossible for the scalare to travel back.  Dirk, you should really come see those "Rio Negro" scalare I got last year.  As they grow they have some very altum like attributes.  Could it be because of hybridization between scalare and altum, or could it be as the disa you described:  The two populations live in quite similar circumstances and have therefore developed similar attibutes over time?  I guess the 3 angelfish species also came from the same ancestor?

    Something else I have read about is where populations change slightly from one point to the other, sometimes in such a way that the first and last populations look quite different.  As you go down the cline though you can see the fish slowly changing in appearance, ray count etc. - It is quite interesting.

    I would just like to add that although I find evolutionary science very interesting, I am very much religious and still believe that all on earth was created by God for his purpose. I know its not normally seen as a good thing to mention religion in conjuction with evolution, but I would just like to state my viewpoint clearly.

    PS. Cameron, I think our discussion was quite interesting when I visited you.
     
  4. Anonymous
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    This would also be true for the Tropheus of Lake Tanganyika which can be separated by falling rock or sand. They can literally be 10 meters away for each other.
     
  5. kevinw
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    I have been following this topic and although a lot (ok, most) of the information goes over my head, I also find this fascinating, but I have to agree with Andre!

    Science without religion is lame, religion without science is blind.
    (Albert Einstein)
     
  6. Anonymous
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    I don't think it's weird or a bad thing. Evolution can very easily tie into religion. But religion is a discussion for another time and place. The next time your up here we can probably have it. ;) So you better make a plan for April.
     
  7. Dirk B
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    Dirk B Aquascaper

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    Hi Andre,

    Just a few quick comments:

    Re the angels: I am convinced that the angels are all closely related. We can clearly separate P scalare, P altum and P leopoldi. The other fish that appear to be intermediate between the two may be hybrids or they may be populations or races of the present species that are in the process of speciating (see my earlier comments about us wanting to pack things into boxes). First generation hybrids all look similar, but the next generation, the so-called F2 then shows combinations of genes of the two original parents ranging from what the one parent looks like to what the other parent looks like. Thus in early hybrid populations you are likely to find a spectrum of intermediates, not fish that all look fairly similar. Your Rio Negros and those of other persons all look similar for which reason they cannot be early hybrids, they must be either be older hybrids or new "species" that are developing from P scalare or P altum. Jared, your comment is relevant in that it may be that these possible hybrids or newly evolving species may now have become separated in the Rio Negro. The bottom line is that unless someone does some fairly fancy population genetics and systematics on these fish, we won't know. Now, if you want to give me the money to do so and it means that I can go to the Amazon to do the collecting, then we can talk......

    With regard to your religious convictions and your finding that there are conflicts with regard to evolution, I would like to try to lay your fears to rest. Firstly, you can either believe that this happened by chance if you are not religious, or if you believe in God, you can easily accommodate evolution to have been conducted by a higher being, but there definitely do not need to be any conflicts. I heard an excellent debate on this very topic a few weeks ago on Radio Sonder Grense by a theologan, in which he commented exactly along these lines. Where the conflicts come in is in the interpretation of the bible. In my opinion, the bible was written for a time in which people had not even thought of evolution, and the way evolution is portrayed in the bible is to make it understandable for those persons. We now have a vast volume of scientific evidence about the time scale of evolution etc. This evidence does not try to refute what was written in the bible at all, the only difference to me is the time scale and the in between steps. Whatever you believe, what amazes me in biological terms is that it is absolutely mindblowing to you think of how many different organisms there are out there. If you are a rational person this amazing biodiversity out there must bring you to the point where you must ask yourself the question whether some higher being did create all of this or whether it evolved by chance, you decide? What concerns me much more, is how we are systematically annihilating all these wonderful creatures for man's short term and selfish gains, in religious terms that is the biggest sin that man is currently committing.

    Now we are really getting heavy....

    Almost PS, Kevinw, I think your Albert Einstein quote does it for me entirely, what a great man.

    Kind regards,

    Dirk
     
  8. Anonymous
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    I suppose if somebody or some university was interested enough they could do the same genetic study on fish as they have recently released on humans. Tracing us all back to a genetic Adam using a mutation in the X chromosome.

    Dirk, if I ever win the lotto we will all go to the Amazon. hehe
     
  9. Andre
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    Andre Green fingers

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    Hi Dirk

    I feel the same way you do, me and Cameron and Jared had a very interesting discussion about this when I visited them and I must say that I found it really interesting to have an open discussion about this without anyone getting too excited and/or angry.  (although I must admit that there was some alcohol involved as well).  I surely learned a lot from Cameron and Jared and I was really amazed at their knowledge on the subject.  I think I can truely say they are as passionate about genetics as I am.  Any chance of us attending some of your lectures? :)
     
  10. Cameron
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    Cameron Green fingers

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    Uncle Dirk is absolutely right, you do not have to throw evolution out the window because you are a religious person, the catholics have adopted evolution as 'part of the picture'. Absolutely nothing wrong with being religious and scientific too. Although i do have severe issues with them teaching creationism in schools over evolution, I expect to hear quite a bit about this next year once evolutionary biology hits the high school text books. Heh :)

    It's been a very nice subject till this point and I would just like to ask members to avoid the religious moral viewpoints. Evolution does relate directly to the subject at hand but your personal religious viewpoints do not. It's always a contentious issue and should probably be best avoided on the forum for obvious reasons.

    This thread cretainly is food for thought, thanks to Len for starting it :)
     
  11. Andre
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    Andre Green fingers

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    Agreed Cameron, sorry for that, but I felt that I needed to raise it as it.

    I must say I learned a lot today :)
     
  12. Cameron
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    Cameron Green fingers

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    No need for apologies at all, I was'nt targetting you specifically, I just felt it would be better to steer clear of any religious arguments that may arise. I'm sure we can all respect each others personal viewpoints and stick to the subject at hand. And as Jared said, hope you can make it in April again ;)

    It surely is an interesting subject, it's all good :)
     
  13. Dirk B
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    Dirk B Aquascaper

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    Hi guys,

    I also wanted to say thanks to you all for a very constructive discussion on all of the issues both scientific and religious. If I have the time to contribute, you can count me in on this sort of thing.

    Cameron, my wife is a biology teacher as a result of which I am of course also fully aware of the fact that evolution is in the new syllabus as of next year. I will be interested to see what sort of emotions that is going to whip up, which, as a have stated before is actually unnecessary.

    Kind regards,

    Dirk
     
  14. d3tained
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    d3tained Algae harvester

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    Hi all.

    Can anybody explain this in simple terms? HEHEHE ( Kidding )

    Im a total noob when it comes to this stuff.
     
  15. Cameron
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    Cameron Green fingers

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    Ditto, really juicy stuff. Thanks for the great in-depth answers Dirk.

    I've been following all the hype 'Intelligent Design' (creationism in disguise) has been creating overseas, last year in the states there was a massive court case (that's how far it went) in Dover, Kansas (Bible belt territory), it got really ugly, in the end the courts overruled the religious fundamentalists and the schools were allowed to teach evolution sans intelligent design. The same process is now happening in the UK! It will be very interesting to see how our country will handle the situation. Personally I don't think there will be much of a struggle, we seem to have taken abortion and stem cell research in our stride so I really don't think evolutionary biology taught in our high schools is going to create much of a stir, hopefully!

    Here's a nice link if you're interested in reading more about it:
    http://www.evolutionnews.org/2005/12/post_6.html
     
  16. Len
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    Len Algae harvester

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    On a non religious subject (although I can see that this might get close to it), if separation can "create"
     
  17. Andre
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    Andre Green fingers

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    Hi Len

    1. Most of the fancy strains of fish like guppies and angels are due to mutations on specific locations on their DNA. For instance in angelfish the genes that cause black, marble and gold angels all occur on the same location. A black angel can still breed with a marble angel. Dogs are also very different but you can cross a st bernard with a dachshund if you tried hard enough :)

    2. I do not think science will recognise a domestic species as there is no guarentee of the bloodline of the fish. The fish could have been hybridized and bred with fish from different locations which would make the mapping and tracing of their DNA impossible.

    3. You can breed wild fish into with domesticated stock. In fact it is recommended to get "new blood" into a strain and eliminate unwanted recessive traits.
     
  18. Peter
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    Peter Algae harvester

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    Lol.......must be a Red Bull trick......lol, maybe a step ladder.. and agree on new blood....Andre you crack me up.....lol
     
  19. Andre
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    Andre Green fingers

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    Yep Peter

    Friends of mine had a cross like that when I was at school. Their st Bernard gave birth to 4 pups, 2 of which were sausage bernards :p
     
  20. Andre
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    Andre Green fingers

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    Hi Len

    Here are some Threads where you can check out the 3 different angelfish species:

    1. Pterophyllum altum

    These are the kings of the aquarium IMHO. They are a much bigger fish and probably more difficult to keep than discus. Reports of them being bred in captivity are few and far between. Seeing a school of these fish at 30cm+ height is probably the most awesome moment since I started keeping fish in glass boxes :).

    http://www.apsa.co.za/board/index.php?topic=558.15

    2. Pterophyllum scalare

    This species is the base for most of the fancy strains of angelfish we seen in our shops. However the wild forms are much more beautiful to my eyes and I was lucky enough to source 2 different types of wild scalare.

    viewtopic.php?t=7

    3. Pterophyllum leopoldi

    Where altums are much heigher bodied than scalare the leopoldi are more elongated and look like a cross between a festivum and a scalare. They have a light brown colour with hints of red and purple in the fins.

    here you can see Henk's school of beautiful leopoldi

    viewtopic.php?t=4.new#new
     

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