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posted by Fnord666 on Tuesday February 06 2018, @03:49PM   Printer-friendly
from the you-say-crayfish-I-say-crawfish dept.

No one knows exactly when the clones first appeared, but humans only became aware of them in the early 2000s.

It was a German aquarium owner who first brought it to scientists' attention. In 1995, he had acquired a bag of "Texas crayfish" from an American pet trader, only to find his tank inexplicably filling up with the creatures. They were all, it turns out, clones. Sometime, somewhere, the biological rule that making baby crayfish required a mama crayfish and papa crayfish was no longer inviolate. The eggs of the hobbyist's all-female crayfish did not need to be fertilized. They simply grew into copies of their "mother"—in a process known as parthenogenesis.

Crayfish specialists were astonished. No one had seen anything like it. But the proof was before their eyes and in 2003, scientists dubbed the creatures marbled crayfish, or Marmorkreb in German.

https://www.theatlantic.com/science/archive/2018/02/attack-of-the-crayfish-clones/552236/


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  • (Score: 0) by Anonymous Coward on Tuesday February 06 2018, @03:59PM (10 children)

    by Anonymous Coward on Tuesday February 06 2018, @03:59PM (#633890)

    Cool, a self-replicating harem.

  • (Score: 3, Touché) by mhajicek on Tuesday February 06 2018, @04:20PM

    by mhajicek (51) on Tuesday February 06 2018, @04:20PM (#633915)

    If they were flying fish shaped like dicks it would be just like 2nd Life.

    --
    The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
  • (Score: 3, Interesting) by c0lo on Tuesday February 06 2018, @04:58PM (7 children)

    by c0lo (156) Subscriber Badge on Tuesday February 06 2018, @04:58PM (#633941) Journal

    I wouldn't call them "female" (as implied by harem). TFA

    Another intriguing fact, says Frank Lyko, who led the study, is that marbled crayfish are triploid, meaning they have three sets of chromosomes. Most crayfish—and most other animals—have two sets, one inherited from the mother and the other from the father. It’s unclear, however, whether these three sets of chromosomes are the cause or consequence of its self-cloning ability. Despite having the DNA sequence in hand, “the reason and origin of parthenogenesis is still somewhat mysterious,” says Gerhard Scholtz, a zoologist at the Humboldt University of Berlin who first described the marbled crayfish in 2003.

    --
    https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
    • (Score: 2) by insanumingenium on Tuesday February 06 2018, @05:32PM (6 children)

      by insanumingenium (4824) on Tuesday February 06 2018, @05:32PM (#633964) Journal

      They lay eggs, how much more female can you get?

      • (Score: 2) by c0lo on Tuesday February 06 2018, @05:55PM (5 children)

        by c0lo (156) Subscriber Badge on Tuesday February 06 2018, @05:55PM (#633985) Journal

        Unlike normal females, the eggs are fertile without the presence of a male.
        So it should be beyond more than (beyond of) a normal female, especially with a triploid genome.

        --
        https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
        • (Score: 2) by insanumingenium on Tuesday February 06 2018, @06:19PM (3 children)

          by insanumingenium (4824) on Tuesday February 06 2018, @06:19PM (#633998) Journal
          Come on, they went from not female to super female. If this logic was a continuous line I would say MVT proves my point, as is I don't think that will work. While we are at it, what sex is attributed to the well known parthenogenesis lizards (amongst other species)? What exactly do you require to use the term female? Cause my test is ovum, seems pretty clearcut to me. Also, you do realize that there are many polyploid species [wikipedia.org], being triploid doesn't negate sex.
          • (Score: 2) by c0lo on Tuesday February 06 2018, @07:20PM (2 children)

            by c0lo (156) Subscriber Badge on Tuesday February 06 2018, @07:20PM (#634047) Journal

            What exactly do you require to use the term female?

            Sexual reproduction with the need of a male sex to produce descendants. But...

            While we are at it, what sex is attributed to the well known parthenogenesis lizards (amongst other species)?

            ... further reading shows that the above definition is too simplistic (so thanks for making me read further.
            I suspect that you'll be pleased to hear that parthenogenesis doesn't necessary produce female only descendants [wikipedia.org] - so "the future is female" is... mmm... greatly exaggerated? (especially when a low genetic diversity means that species extinction due to an illness is almost a certitude on long terms)

            Also, you do realize that there are many polyploid species [wikipedia.org], being triploid doesn't negate sex.

            I'm curious, so I'll be grateful for any detailed study about sexual reproduction in triploids that maintains the triplod trait as a species constant

            The line of my thinking - chances are the offspring to show a dispersion between diploid and tetraploid on different chromosomes, with an average 50% of chromosomes in triplicate, 25% in pairs and 25% chromosomes in tetraploid state in the first generation (meiosis II produces haploids and diploids with equal frequency)
            The chances of "all chromosomes in triplicate" is (1/2)N, where N is the number of chromosomes. To have a pure triiploid species using sexual reproduction exclusively would require:
            1. any non-triploid chromosome in the set is a death warrant (otherwise you'll never see a pure triploid species)
            2. a small number of chromosomes (and thus a non-infinitesimal chance of all-chromosome triploids) and/or a huge number of offspring so the (1/2)N chance still offer chances of some viable descendants. E.g. 20 chromosomes will result in a "all triploid" configuration with a chance of 1 in a million viability.

            --
            https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
            • (Score: 2) by insanumingenium on Tuesday February 06 2018, @08:22PM (1 child)

              by insanumingenium (4824) on Tuesday February 06 2018, @08:22PM (#634070) Journal
              Did you happen to notice that while I did cherry pick the whiptail lizards, the paragraph you are referencing actually directly contradicts you.

              In polyploid obligate parthenogens like the whiptail lizard, all the offspring are female.[19]

              Let's see

              polyploid - check
              obligate parthogens - no males fo this species exist - check

              You want a polyploid that breeds true, take one of my favorites The California Redwood [wikipedia.org], it is a hexaploid the reproduces sexually. If you want a triploid in particular, you are correct that it doesn't usually breed true, breeding is an integer process (usually, though some fungi are really weird), and three into two makes awkward math.

              Also, in case I haven't beat this horse enough, and since you seem to like wikipedia as a source, please see here for the definition of female [wikipedia.org]

              • (Score: 2) by c0lo on Tuesday February 06 2018, @11:13PM

                by c0lo (156) Subscriber Badge on Tuesday February 06 2018, @11:13PM (#634166) Journal

                You want a polyploid that breeds true

                No, I wanted an example ofa pure triploid with sexual repro.
                Examples of even-ploidy reproducing sexually are quite common in the plant world.

                --
                https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
        • (Score: 3, Interesting) by frojack on Tuesday February 06 2018, @06:55PM

          by frojack (1554) on Tuesday February 06 2018, @06:55PM (#634025) Journal

          the eggs are fertile without the presence of a male.

          Define fertile.

          They only grow into clones, this sounds more akin to what Planarian flatworms do when they re-form clones from slivers 1/300th of their original size. To do this, planarians use stem cells, called cNeoblasts, that have the ability to become almost any cell type in the body. I'd speculate this is the same sort of stem-cell process, but instead of worm sections , the stem cells are in the eggs).

          I don't think the concept of fertility applies here. The process is probably orthogonal to fertility in that it is entirely asexual.

          --
          No, you are mistaken. I've always had this sig.
  • (Score: 3, Insightful) by Freeman on Tuesday February 06 2018, @05:54PM

    by Freeman (732) on Tuesday February 06 2018, @05:54PM (#633984) Journal

    So, Jurassic Park was on the right track, then?

    "
    Ian Malcolm: God creates dinosaurs. God destroys dinosaurs. God creates man. Man destroys God. Man creates dinosaurs.
    Ellie Sattler: Dinosaurs eat man…woman inherits the earth.
    "

    --
    Joshua 1:9 "Be strong and of a good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee"