Science&Future

EVOLUTIONSBIOLOGIE UNTER NEUER PERSPEKTIVE

1.035 Kommentare

Anhand von farbenfrohen Hamletbarschen erforschten Wissenschaftler des GEOMAR Helmholtz-Zentrums für Ozeanforschung Kiel und des Smithsonian Tropical Research Institute in Panamaeine der grundlegenden Fragen der Evolutionsbiologie: „Wie können neue Arten im Meer entstehen?“ Dies ist besonders unter dem Aspekt interessant, dass die karibischen Riffbarsche eigentlich nahe beieinander leben und sich auch weiterhin miteinander fortpflanzen können.

Die Forschenden entdeckten bei ihren Untersuchungen, wie die natürliche Selektion auf die Weiterentwicklung von Genen im Bereich der visuellen Wahrnehmung und damit einhergehend der Ausprägung von Farbmustern wirkt. So ist es zumindest bei den Hamlets der Fall, dass die blaue Fischart meistens blaue Partner bevorzugt, während die rote Art eher auf rote Partner anspricht. Das heißt, die einzigartige Farbgebung bedingt auch die Vorliebe für die Ausprägung dieser Farbeigenschaft bei der Partnerwahl.

Dies ist einer der Gründe, warum die Forschung lange vermutete, dass sich neue Arten nur in absoluter Isolation und ohne Kreuzung entwickeln können. Sofern sich in diesem Falle beide Arten untereinander vermischten, ging man davon aus, dass hier die codierten Merkmale zwischen Farb- und Paarungsvorlieben, die sogenannte Kopplung, durch die sexuelle Rekombination – die Neuanordnung von genetischem Material in den Zellen –, zerstört wird. In Folge dessen hätten rote Individuen eine Präferenz für blaue Partner und umgekehrt.

VERWANDTE ARTEN MIT DEUTLICHEN CHARAKTERISTIKA

Ein gestreifter Hamletbarsch (Hypoplectrus puella) vor der Küste Panamas ©Kosmas Hench/GEOMAR

Doch stellten die Wissenschaftler um Oscar Puebla, Professor am GEOMAR Helmholtz-Zentrum für Ozeanforschung in Kiel, in Zusammenarbeit mit Kolleginnen und Kollegen am Smithsonian Tropical Research Institute (STRI), fest, dass bei der natürlichen Selektion miteinander verwandter Arten codierte Merkmale für Farbmuster und Paarungspräferenzen eben nicht neu kombiniert werden.

Für ihre Untersuchungen hatten die Wissenschaftler einige Hürden zu meistern: „Die erste Herausforderung unserer Studie bestand darin, eine Tiergruppe zu finden, in der sich erst vor kurzer Zeit neue Arten entwickelt haben, die aber deutliche Charakteristika aufweisen“, so Puebla. Genau so eine Gruppe bilden die Hamletbarsche. Mehrere eng verwandte Arten von ihnen leben an den Riffen der gesamten Karibik. Die einzelnen Arten sind genetisch sehr ähnlich. Ihr Hauptunterschied ist das jeweilige Farbmuster, während die Präferenz für verschiedene Farbmuster bei der Paarung die Arten getrennt hält.

IDENTIFIZIERUNG DER GENE

Für die Forschenden galt es zudem, die Gene zu identifizieren, die den Unterschied zwischen den Arten und den Paarungspräferenzen ausmachen. Hierfür sequenzierten die Wissenschaftler zunächst das gesamte Genom von 110 Riffbarschen aus Panama, Belize und Honduras. Im Anschluss untersuchten sie bei den Fischen, worin sich das Genom unterscheidet. Denn alle drei untersuchten Arten leben zusammen in denselben Riffen.

„Dieser umfassende Datensatz ermöglichte es uns, vier eng begrenzte Regionen des Genoms zu identifizieren, die bei allen Arten deutliche Unterschiede aufzeigten, während der Rest des Genoms bei allen Arten kaum Differenzierung zeigte“, erklärt Kosmas Hench, Doktorand am GEOMAR und Erstautor der Studie. Denn genau diese vier Regionen beinhalten die Gene, die die visuelle Wahrnehmung sowie die Farbmuster der Fische beeinflussen.

Obwohl sich die Arten untereinander paaren, zeigen die Daten, dass die Konstellationen der Seh- und Farbmustergene sich nicht verändern. Die entsprechenden Gene sind also gekoppelt (haben codierte Merkmale) und sind so vor sexueller Rekombination (Neuordnung von genetischem Material) geschützt. Das Besondere an dem Ergebnis ist zudem, dass sich die Gene im Fall der Hamletbarsche auf drei verschiedenen Chromosomen befinden. Bisher kannte man solche Gen-Koppelungen nur, wenn die Gen-Sätze auf einem Chromosom sehr nahe beieinander lagen. So konnte das Team zeigen, wie die natürliche Selektion zur Entstehung neuer Formen in einer sehr frühen Phase der Artenbildung beitragen kann.

WEITERE FORSCHUNGEN

Die Wissenschaftler vermuten, dass ihre Ergebnisse auch noch auf andere Arten übertragbar sind. Doch dafür bedarf es zusätzlicher Untersuchungen, weshalb als nächster Schritt weitere der bisher 19 beschriebenen Hamlet-Arten erforscht werden sollen. Damit wollen die Wissenschaftler herausfinden, ob sich das gefundene Muster allgemein durch die Familie der Hamletbarsche zieht, oder ob es einen Spezialfall der drei untersuchten Arten darstellt.

Grundsätzlich ist übrigens denkbar, dass die natürliche Selektion auch bei anderen Faktoren, die der Partnerwahl dienen, funktioniert. So ist es möglich, dass hier eventuell auch Geruch, Größe oder das Verhalten wirken. Die Studie erschien Anfang März in der Fachzeitschrift Nature Ecology and Evolution.

Bild oben: Professor Oscar Puebla bei Feldarbeiten im Lebensraum der Hamletbarsche vor Puerto Rico ©Kosmas Hench/GEOMAR

Dieser Artikel erschien am 5. März in der Innovation Origins.

1.035 Gedanken zu „EVOLUTIONSBIOLOGIE UNTER NEUER PERSPEKTIVE“

  114. Pingback: tinder online not working
  118. Pingback: viagra para mujeres
  123. Pingback: hiv dating sites that are completely free
  125. Pingback: generic for cialis in the usa
  127. Pingback: best dating sites for free
  129. Pingback: which dating sites are really free
  136. Pingback: pill pharmacy
  139. Pingback: cialis overnight pharmacy
  140. Pingback: cialis canadian pharmacy
  141. Pingback: cialis 5mg how long does it take to work
  156. Pingback: christian free dating sites
  157. Pingback: free christan dating site
  158. Pingback: free dating events

  176. Hello I am so grateful I found your website, I really found you by error, while
    I was researching on Yahoo for something else, Regardless I am
    here now and would just like to say cheers for a incredible post and a all round thrilling blog (I also love the theme/design),
    I don’t have time to read through it all at the moment
    but I have saved it and also added your RSS feeds, so when I have time
    I will be back to read more, Please do keep up the superb work. http://canadiandrugstorerx.com/antibiotics/amoxil.html

  266. Pingback: free online dating ghana
  277. Pingback: new zealand dating free

  280. I think that everything said was very reasonable. However, consider this, what if you added a little information? I am not suggesting your content is not solid, however what if you added a post title that makes people want
    more? I mean EVOLUTIONSBIOLOGIE UNTER NEUER PERSPEKTIVE | ottopress is kinda plain. You ought
    to peek at Yahoo’s home page and note how they create news headlines to grab people
    interested. You might try adding a video or a related pic or two to grab
    people interested about what you’ve got to say. Just my opinion, it might bring your posts a little livelier. http://herreramedical.org/ivermectin

  308. Pingback: cytotmeds.com
  315. Pingback: prednisone tablets for sale
  322. Pingback: what country makes hydroxychloroquine
  334. Pingback: generic dapoxetine uk

  337. Usually I don’t read article on blogs, but I wish to say that this write-up very forced me to check out and do so! Your writing style has been surprised me. Thanks, quite great post.

  342. Vedik astroloji ve öngörü yöntemleri uzmanı vedik astrolog Hakan Kalkan burç yorumları ile Youtube kanalımızda sorularınıza cevap sorunlarınıza çözüm buluyor.

  370. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  380. Usually I do not read post on blogs, but I would like to say that this write-up very pressured me to try and do it! Your writing taste has been surprised me. Thank you, very nice post.

  393. Usually I don’t read article on blogs, but I wish to say that this write-up very forced me to check out and do so! Your writing style has been surprised me. Thanks, quite great post.

  397. Usually I don’t read article on blogs, but I wish to say that this write-up very forced me to check out and do so! Your writing style has been surprised me. Thanks, quite great post.

  402. Usually I don’t learn post on blogs, however I wish to say that this write-up very pressured me to take a look at and do it! Your writing taste has been surprised me. Thanks, very nice post.

  408. Unquestionably believe that which you said. Your favorite reason seemed to be on the web the simplest thing to be aware of. I say to you, I certainly get annoyed while people think about worries that they just do not know about. You managed to hit the nail upon the top and also defined out the whole thing without having side effect , people can take a signal. Will likely be back to get more. Thanks

  445. Usually I don’t learn post on blogs, however I wish to say that this write-up very pressured me to take a look at and do it! Your writing taste has been surprised me. Thanks, very nice post.

  456. Vedik astroloji ve öngörü yöntemleri uzmanı vedik astrolog Hakan Kalkan burç yorumları ile Youtube kanalımızda sorularınıza cevap sorunlarınıza çözüm buluyor.

  478. Usually I don’t read article on blogs, but I wish to say that this write-up very forced me to check out and do so! Your writing style has been surprised me. Thanks, quite great post.

  483. Vedik astroloji ve öngörü yöntemleri uzmanı vedik astrolog Hakan Kalkan burç yorumları ile Youtube kanalımızda sorularınıza cevap sorunlarınıza çözüm buluyor.

  485. Vedik astroloji ve öngörü yöntemleri uzmanı vedik astrolog Hakan Kalkan burç yorumları ile Youtube kanalımızda sorularınıza cevap sorunlarınıza çözüm buluyor.

  486. Usually I don’t read article on blogs, but I wish to say that this write-up very forced me to check out and do so! Your writing style has been surprised me. Thanks, quite great post.

  490. Vedik astroloji ve öngörü yöntemleri uzmanı vedik astrolog Hakan Kalkan burç yorumları ile Youtube kanalımızda sorularınıza cevap sorunlarınıza çözüm buluyor.

  491. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  494. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  515. Very interesting details you have mentioned , appreciate it for putting up. “I don’t know what you could say about a day in which you have seen four beautiful sunsets.” by John Glenn.

  538. Very interesting points you have mentioned , regards for putting up. “It’s the soul’s duty to be loyal to its own desires. It must abandon itself to its master passion.” by Rebecca West.

  545. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  581. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  588. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  603. Usually I don’t read article on blogs, but I wish to say that this write-up very forced me to check out and do so! Your writing style has been surprised me. Thanks, quite great post.

  606. Usually I don’t read article on blogs, but I wish to say that this write-up very forced me to check out and do so! Your writing style has been surprised me. Thanks, quite great post.

  609. Usually I don’t read article on blogs, but I wish to say that this write-up very forced me to check out and do so! Your writing style has been surprised me. Thanks, quite great post.

  613. Unquestionably consider that which you said. Your favourite justification appeared to be on the net the easiest thing to have in mind of. I say to you, I definitely get annoyed at the same time as other people think about issues that they just don’t know about. You managed to hit the nail upon the top and also defined out the entire thing without having side-effects , other folks could take a signal. Will probably be again to get more. Thank you

  618. Vedik astroloji ve öngörü yöntemleri uzmanı vedik astrolog Hakan Kalkan burç yorumları ile Youtube kanalımızda sorularınıza cevap sorunlarınıza çözüm buluyor.

  623. Usually I don’t learn post on blogs, however I wish to say that this write-up very pressured me to take a look at and do it! Your writing taste has been surprised me. Thanks, very nice post.

  627. Vedik astroloji ve öngörü yöntemleri uzmanı vedik astrolog Hakan Kalkan burç yorumları ile Youtube kanalımızda sorularınıza cevap sorunlarınıza çözüm buluyor.

  636. Usually I don’t learn post on blogs, however I wish to say that this write-up very pressured me to take a look at and do it! Your writing taste has been surprised me. Thanks, very nice post.

  641. Usually I don’t read article on blogs, but I wish to say that this write-up very forced me to check out and do so! Your writing style has been surprised me. Thanks, quite great post.

  646. Very interesting details you have mentioned , appreciate it for putting up. “I don’t know what you could say about a day in which you have seen four beautiful sunsets.” by John Glenn.

  656. Usually I don’t learn post on blogs, however I wish to say that this write-up very pressured me to take a look at and do it! Your writing taste has been surprised me. Thanks, very nice post.

  674. Useful information. Fortunate me I discovered your site unintentionally, and I’m stunned why this coincidence didn’t came about in advance! I bookmarked it.

  675. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  677. Usually I don’t learn post on blogs, however I wish to say that this write-up very pressured me to take a look at and do it! Your writing taste has been surprised me. Thanks, very nice post.

  701. Vedik astroloji ve öngörü yöntemleri uzmanı vedik astrolog Hakan Kalkan burç yorumları ile Youtube kanalımızda sorularınıza cevap sorunlarınıza çözüm buluyor.

  714. Vedik astroloji ve öngörü yöntemleri uzmanı vedik astrolog Hakan Kalkan burç yorumları ile Youtube kanalımızda sorularınıza cevap sorunlarınıza çözüm buluyor.

  729. Vedik astroloji ve öngörü yöntemleri uzmanı vedik astrolog Hakan Kalkan burç yorumları ile Youtube kanalımızda sorularınıza cevap sorunlarınıza çözüm buluyor.

  734. Usually I don’t read article on blogs, but I wish to say that this write-up very forced me to check out and do so! Your writing style has been surprised me. Thanks, quite great post.

  739. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  751. Vedik astroloji ve öngörü yöntemleri uzmanı vedik astrolog Hakan Kalkan burç yorumları ile Youtube kanalımızda sorularınıza cevap sorunlarınıza çözüm buluyor.

  758. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  782. Unquestionably believe that which you stated. Your favorite justification seemed to be on the net the easiest thing to be aware of. I say to you, I certainly get irked while people consider worries that they just do not know about. You managed to hit the nail upon the top as well as defined out the whole thing without having side effect , people could take a signal. Will probably be back to get more. Thanks

  786. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  788. Useful information. Fortunate me I discovered your site unintentionally, and I’m stunned why this coincidence didn’t came about in advance! I bookmarked it.

  801. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  805. Usually I don’t learn post on blogs, however I wish to say that this write-up very pressured me to take a look at and do it! Your writing taste has been surprised me. Thanks, very nice post.

  815. Usually I don’t read article on blogs, but I wish to say that this write-up very forced me to check out and do so! Your writing style has been surprised me. Thanks, quite great post.

  843. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  854. Unquestionably believe that which you said. Your favorite reason seemed to be on the web the simplest thing to be aware of. I say to you, I certainly get annoyed while people think about worries that they just do not know about. You managed to hit the nail upon the top and also defined out the whole thing without having side effect , people can take a signal. Will likely be back to get more. Thanks

  858. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  861. Unquestionably believe that which you stated. Your favorite justification seemed to be on the net the easiest thing to be aware of. I say to you, I certainly get irked while people consider worries that they just do not know about. You managed to hit the nail upon the top as well as defined out the whole thing without having side effect , people could take a signal. Will probably be back to get more. Thanks

  862. tsyepocd,A fascinating discussion is definitely worth comment. I do think that you ought to publish more on this topic, it may not be a taboo dnaajqtlyi,subject but generally folks don’t talk about such subjects. To the next! All the best!!

  868. Unquestionably believe that which you stated. Your favorite justification seemed to be on the net the easiest thing to be aware of. I say to you, I certainly get irked while people consider worries that they just do not know about. You managed to hit the nail upon the top as well as defined out the whole thing without having side effect , people could take a signal. Will probably be back to get more. Thanks

  882. Usually I don’t read article on blogs, but I wish to say that this write-up very forced me to check out and do so! Your writing style has been surprised me. Thanks, quite great post.

  889. Unquestionably believe that which you said. Your favorite justification appeared to be on the net the easiest thing to be aware of. I say to you, I certainly get irked while people think about worries that they just don’t know about. You managed to hit the nail upon the top and also defined out the whole thing without having side-effects , people could take a signal. Will probably be back to get more. Thanks

  891. Unquestionably believe that which you said. Your favorite reason seemed to be on the web the simplest thing to be aware of. I say to you, I certainly get annoyed while people think about worries that they just do not know about. You managed to hit the nail upon the top and also defined out the whole thing without having side effect , people can take a signal. Will likely be back to get more. Thanks

  892. Unquestionably consider that which you said. Your favourite justification appeared to be on the net the easiest thing to have in mind of. I say to you, I definitely get annoyed at the same time as other people think about issues that they just don’t know about. You managed to hit the nail upon the top and also defined out the entire thing without having side-effects , other folks could take a signal. Will probably be again to get more. Thank you

  901. tweet my newest twitter updates. I’ve been looking for a plug-in like this for quite some time and was hoping maybe you would have some experience with something like this.

  906. Unquestionably believe that which you said. Your favorite justification appeared to be on the net the easiest thing to be aware of. I say to you, I certainly get irked while people think about worries that they just don’t know about. You managed to hit the nail upon the top and also defined out the whole thing without having side-effects , people could take a signal. Will probably be back to get more. Thanks

  933. Today, while I was at work, my cousin stole my apple ipad and tested to see if it can survive a 30 foot drop, just so she can be a youtube sensation. My iPad is now broken and she has 83 views. I know this is entirely off topic but I had to share it with someone!

  961. Usually I don’t learn article on blogs, but I would like to say that this write-up very forced me to try and do so! Your writing taste has been surprised me. Thanks, quite nice post.

  972. Unquestionably believe that which you said. Your favorite justification appeared to be on the net the easiest thing to be aware of. I say to you, I certainly get irked while people think about worries that they just don’t know about. You managed to hit the nail upon the top and also defined out the whole thing without having side-effects , people could take a signal. Will probably be back to get more. Thanks

  974. tweet my newest twitter updates. I’ve been looking for a plug-in like this for quite some time and was hoping maybe you would have some experience with something like this.

  976. tsyepocd,A fascinating discussion is definitely worth comment. I do think that you ought to publish more on this topic, it may not be a taboo dnaajqtlyi,subject but generally folks don’t talk about such subjects. To the next! All the best!!

  984. Undeniably believe that which you said. Your favorite reason appeared to be on the web the simplest thing to be aware of. I say to you, I definitely get irked while people consider worries that they just don’t know about. You managed to hit the nail upon the top as well as defined out the whole thing without having side effect , people could take a signal. Will probably be back to get more. Thanks

  996. Pingback: c14 dating free download
  1026. Pingback: canadian generic priligy
  1027. Pingback: keto diet and heart disease
  1029. Pingback: keto protein
  1031. Pingback: keto creamed spinach

Kommentare sind geschlossen.