FoxNews.com - Pollution Causes Homosexuality in Birds, Study Suggests
En las aves estudiadas, el playismo es desorden metabólico provocado por mercurio en el medio ambiente.
Para los que argumentan que es "natural", ocurre en la naturaleza pero en este ejemplo resulta que la causa es enteramente antinatural.
The nature versus nurture debate just took an unexpected turn -- thanks to pollution.
Increased exposure to the toxic chemical mercury can affect sexual preference in certain species ************SPAM/BANNEAR************ birds -- inducing homosexuality, a new study has revealed.
Peter Frederick, an ecologist from the University ************SPAM/BANNEAR************ Florida, and Nilmini Jayasena from the University ************SPAM/BANNEAR************ Peradeniya in Sri Lanka found that male American white ibises that consumed methylmercury, the most toxic and easily digested form ************SPAM/BANNEAR************ mercury found in the environment, were more likely to pair with other males. In wild ibis populations with no mercury exposure, same-sex pairing is non-existent.
"We knew that mercury was likely to affect reproductive hormones from an earlier study," Frederick told FoxNews.com, "so we suspected some aspect ************SPAM/BANNEAR************ reproduction would be affected, like whether the birds came into reproductive condition or whether they were too aggressive to pair."
"We had no clue that mate choice might be involved," he added.
Birds living in wetlands, such as the ibises, are most vulnerable because the environment is a breeding ground for bacteria that convert the mercury spewed from coal-fired power plants into methylmercury, which "is at least ten times as toxic as the stuff in a thermometer," Frederick said.
Mercury becomes methylated ************SPAM/BANNEAR************ when it comes in contact with bacteria in anoxic environments, those that use sulfur instead ************SPAM/BANNEAR************ oxygen for metabolism. And that process is common in wetlands and shallow aquatic areas, Frederick said.
"The implication is that this is probably happening in wild bird populations," Frederick told Nature magazine.
Frederick and Jayasena studied 160 white ibis nestlings over a three-year period. They found that males with higher levels ************SPAM/BANNEAR************ mercury were less likely to be approached by females and had a higher chance ************SPAM/BANNEAR************ being involved in a homosexual pairing. As the level ************SPAM/BANNEAR************ mercury exposure increased, so did the degree and persistence ************SPAM/BANNEAR************ homosexual pairing.
Frederick believes that the methylmercury, a known endocrine disruptor, is affecting hormone levels in exposed birds.
En las aves estudiadas, el playismo es desorden metabólico provocado por mercurio en el medio ambiente.
Para los que argumentan que es "natural", ocurre en la naturaleza pero en este ejemplo resulta que la causa es enteramente antinatural.