Bdelloid Rotifers Abandoned Sex 100 Million Years Ago

Posted on March 21, 2007  Comments (7)

Who Needs Sex (or Males) Anyway? by Liza Gross:

If you own a birdbath, chances are you’re hosting one of evolutionary biology’s most puzzling enigmas: bdelloid rotifers. These microscopic invertebrates—widely distributed in mosses, creeks, ponds, and other freshwater repositories—abandoned sex perhaps 100 million years ago, yet have apparently diverged into nearly 400 species. Bdelloids (the “b” is silent) reproduce through parthenogenesis, which generates offspring with essentially the same genome as their mother from unfertilized eggs.

Scientists stumped by 100m years of chastity

Bdelloid rotifers are egg laying microscopic invertebrates — widely distributed in mosses, streams and ponds — which have managed to diverge into nearly 400 species without a scintilla of sex… Now a new study, published today in the journal PLoS biology, has confirmed the worst fears of scientists: the rotifers do indeed present a major challenge to the assumption that sex is necessary for organisms to diversify into species.

Rather than mixing up DNA, creatures like the bdelloid rotifers can evolve solely through the build-up of mutations that occur in the ‘cloning’ process when a new rotifer is born. The new study proves that these differences are not random and can help rotifers adapt to a different environment, such as the legs or chest of a water louse. Bdelloids can be found happily swimming around in a puddle in your garden, hot springs or in freezing ponds in the Antarctic.

7 Responses to “Bdelloid Rotifers Abandoned Sex 100 Million Years Ago”

  1. Curious Cat Science and Engineering Blog » Sexy Math
    August 23rd, 2007 @ 8:08 pm

    For awhile now I have noticed “sex 100”³ showing up as one of the terms guiding the most visitors to this site. I wondered what that could be – I just took a look: Bdelloid Rotifers Abandoned Sex 100 Million Years Ago. I think maybe those searchers didn’t exactly find what they wanted…

  2. CuriousCat: One Species' Genome Discovered Inside Another's
    September 13th, 2007 @ 6:17 pm

    “More incredible gene research. Scientists at the University of Rochester and the J. Craig Venter Institute have discovered a copy of the genome of a bacterial parasite residing inside the genome of its host species…”

  3. Curious Cat » Androgenesis
    April 1st, 2008 @ 5:05 pm

    “Androgenesis is what happens when kids get all their genes from their father…”

  4. Curious Cat: I Support the Public Library of Science
    June 15th, 2008 @ 12:03 pm

    I am a fan of the Public Library of Science, as I have mentioned previous. Yesterday I donated some money to support their great efforts…

  5. Curious Cat Science Blog » Virgin Birth for Another Shark Species
    October 14th, 2008 @ 6:20 pm

    “a blacktip shark… had spent nearly her entire eight years at either the Virginia Aquarium without any male companionship from her kind…”

  6. Curious Cat Science Blog » Fungus-gardening Ant Species Has Given Up Sex Completely
    January 10th, 2010 @ 3:37 pm

    Queens of the ant Mycocepurus smithii reproduce without fertilization and males appear to be completely absent…

  7. Curious Cat Science and Engineering Blog » Researchers Explain How Rotifers Thrive Despite Forgoing Sex
    February 21st, 2010 @ 7:44 pm

    […] Bdelloid Rotifers Abandoned Sex 100 Million Years Ago – Fungus-gardening Ant Species Has Given Up Sex Completely – Amazon Molly Fish are All […]

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