Female sharks fertilize own eggs

Discussion in 'IntroSpectrum' started by identity-X, May 27, 2007.

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  1. identity-X

    identity-X No Talent Assclown

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    iiiiiiiiiiiiiinteresting...

    http://news.yahoo.com/s/ap/virgin_births_sharks

    UBLIN, Ireland - Female sharks can fertilize their own eggs and give birth without sperm from males, according to a new study of the asexual reproduction of a hammerhead in a U.S. zoo.
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    The joint Northern Ireland-U.S. research, being published Wednesday in the Royal Society's peer-reviewed Biology Letter journal, analyzed the DNA of a shark born in 2001 in the Henry Doorly Zoo in Omaha, Neb. The shark was born in a tank with three potential mothers, none of whom had contact with a male hammerhead for at least three years.

    The baby was killed within hours of its birth by a stingray in the same tank. Analysis of its DNA found no trace of any chromosomal contribution from a male partner.

    Shark experts said this was the first confirmed case in a shark of parthenogenesis, which is derived from Greek and means "virgin birth."

    Asexual reproduction is common in some insect species, rarer in reptiles and fish, and has never been documented in mammals. The list of animals documented as capable of the feat has grown along with the numbers being raised in captivity — but until now, sharks were not considered a likely candidate.

    "The findings were really surprising because as far as anyone knew, all sharks reproduced only sexually by a male and female mating, requiring the embryo to get DNA from both parents for full development, just like in mammals," said marine biologist Paulo Prodohl of Queen's University of Belfast, Northern Ireland, a co-author of the report.

    "As is typical with scientists, we doubted our own results and so we did it again, and then a third time using a new technique with new genetic approaches. This confirmed there was no DNA of any male," said Prodohl, an expert in fish genetics with specific knowledge of hammerhead DNA.

    Before the study, many shark experts had presumed that the Nebraska birth involved a female shark's well-documented ability to store sperm for months. This seemed the most plausible scenario even though the sharks had arrived at the Nebraska zoo as immature pups.

    The lack of any paternal DNA in the baby shark ruled out this possibility.

    "This phenomenon has now been demonstrated in all major vertebrate groups except for mammals. Birds do it, reptiles do it, amphibians do it, fishes do it, and now sharks are known to do it," said Bob Hueter, director of the Center for Shark Research at the Mote Marine Laboratory in Sarasota, Fla., who was not involved in the project.

    The report's other co-author, Mahmood Shivji of the Guy Harvey Research Institute in Dania Beach, Fla., said the finding explained growing numbers of anecdotal reports of male-free shark births in captivity.

    Shivji said the research "may have solved a general mystery about shark reproduction," because it suggests that sharks can "switch from a sexual to a non-sexual mode of reproduction." But he said this was not necessarily a positive ability because baby sharks produced only by the mother suffer from reduced genetic diversity.

    Genetic diversity makes living creatures better able to adapt to threats, such as disease and climate change.

    Prodohl said if self-impregnation was occurring in the wild because female sharks cannot find male partners amid rapidly declining shark populations, it would represent "an evolutionary dead end that compromises the survival of the species."

    He said he suspected this was "already a problem in the real world," and noted the population of blue sharks off the west coast of Ireland had fallen by 90 percent in the past 12 years.

    But Hueter said he doubted it was happening anywhere besides in captivity. He also argued that the power to self-impregnate represents "an evolutionary strategy to keep the population and species going when all else fails. Genetically, it's a last resort tactic because it leads to genetic uniformity, and eventually that will catch up with the population and make it less fit.

    "But as a short-term alternative to extinction, it has its benefits," he said.
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  2. SapphireWine

    SapphireWine staring at the sun

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    Aren't sharks considered fish?
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  3. UnbrokeN

    UnbrokeN Well-Known Member

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    lol...then hopefully, when all else fails, western women will aquire this ability so we dont have to die out :)
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  4. Look im Gangsta

    Look im Gangsta New Member

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    Of course it interests you, you feminine prick.

    I bet it eats away at you, that you had to stoop to such dirty and manly ickyness, to knock up your old lady with your kid.
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  5. menaz

    menaz Avant Garde

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    Too bad the same can't be said about humans.

    You're always gonna need that male spunk.

    Whether artificially integrated or good old fashion fucking... The male role in life is forever or at least until the Sun destories the earth.
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  6. SapphireWine

    SapphireWine staring at the sun

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    I think the article clearly says the shark population would suffer without the male contribution.
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  7. menaz

    menaz Avant Garde

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    ^Be careful nexttime you enter the ocean feminist sharks will attack.
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  8. SapphireWine

    SapphireWine staring at the sun

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    haha, Menaz. Don't you know 'feminist' sharks only seem to exist in captivity?
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  9. menaz

    menaz Avant Garde

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    Incase you didn't know the ocean is male. We should protest against salt water for being a male-chauvinist. But Then again, prehaps these feminist sharks keep themselves captive with ideological nonsense.
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  10. menaz

    menaz Avant Garde

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    Don't let the religioisty on this site see you saying this. They might write 200 page essays noone will read on christ actually being a martian from the planet Egypt.

    Stranger things have happend!
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  11. SapphireWine

    SapphireWine staring at the sun

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    What do you mean the ocean is male? [look]

    No, they're forced into captivity.
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  12. menaz

    menaz Avant Garde

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    can't read metphorical sarcasm? You think egypts a planet as well?

    Oh no feminist sharks in captivity, all captors are male blame the male captors.

    Noone gives a shit! And I hate fuckin' sharks.
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  13. SapphireWine

    SapphireWine staring at the sun

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    Cause that made sense.

    When did I say the captors were male, anyway?
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  14. menaz

    menaz Avant Garde

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    Seems to me you have no perception for sarcasm or for my over the top condescending everything that controls is male, comedy. Do youself a favor get a personality and learn what sarcasm is. If I gave a shit about anything in this thread my language would not be comical or scarcastic it would be vicious.
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  15. SapphireWine

    SapphireWine staring at the sun

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    hahahaha.

    You have issues. Don't be a fool. If you're going to be •••••••••, you have to actually allude to something within the topic. You must be fun at parties.
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  16. menaz

    menaz Avant Garde

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    Speaking of parties, I got back from celebrating my glorious brithday.

    You're idea of having fun at a party is everyone talking about boring topics such as this one? And you have the nerve to assume I'm no fun at parties? LOL!

    And again you still don't understand sarcasm. You're the typical argumentive moron. So that would make you that guy everyone hates at parties.

    Speaking away from the hypotheical of who or who wouldn't be fun at a party. This is a thread not a party. A thread only you seem to care about. Everyone else knows the real intent of this thread, which is why noone is taking it serious or answering it in the way you desire. Sometimes you have to read between the lines.

    Without a doubt you are dumbest person I have talked to on here.
    Notice I'm not even arguing with you? That's because I was never arguing in the first place. If I really wanted to I could come in this thread
    and start talking about anything and you couldn't do a thing about it.
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  17. SapphireWine

    SapphireWine staring at the sun

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    Happy birthday, Menny!!
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  18. menaz

    menaz Avant Garde

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    Thank you, Alias!
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  19. SapphireWine

    SapphireWine staring at the sun

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    Funny, Menny.

    So, what did your friends/family get you? And how old are you now?

    YW, Menaz.
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  20. menaz

    menaz Avant Garde

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    I'm 24 now, They gave me alot of money.

    After I paid my booky.... I went to the strip club with some friends.
    Went home, Got a blowjob, had sexytime, and went to bed.
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