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Here is a link to an article on Feminized Fish. The male fish are now producing eggs and showing secondary female sex chacteristics. They say this is from birth control bills and hormone treatments being dumped in the water.
http://apnews.excite.com/article/20090914/D9ANBN800.html
Hugs,
Jenna From FL
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Either or...
There are some reptiles, and fish and amphibians...that depending on the phermones (are there any females present) cause males to become females. Does any one remember Jurassic Park. There, they limited the populations of the dinosaurs to only males...to control the population. To prevent reproduction. But since they used amphibian DNA to make up the missing sequences in the dinosaur DNA. The dinosaurs were able to reproduce, out of control. Mother Nature always wins. Mary
Jurassic Park
All the dinosaurs were female. Remember he asked if they went out and lifted their skirts to check it?
With damselfish (the ones that live in the waving fronds of the stinging arms of the coral etc) one male runs a harem of females. If the male is removed, the dominant female will ascend and become male and take over the harem. There have been instances in fresh water fish, where a female swordtail will take on male characteristics ie, the elongated sword from the tail and more, but they have not shown themselves to be fertile and capable of impregnating females, although they will attempt to mate with a female.
Don't some detergents
and anti surfactants have an oestrogenic effect as well as all the oestrogens I'm weeing?
Angharad
Angharad
Anything in plastic bottles
I suppose that it takes a certain type of plastic, but Milk in plastic bottles certainly contains Oestrogen both from the cow and the bottle. That's a lot of "bottle", eh? :)
estrogenic effects.
What we wee into the water system is minimal compared to the dumping by the pharmaceutical industry in manufacture of birth control pills. And even more pervasive is the livestock/dairy industry feeding hormones to their livestock to get them to produce more milk and get with calf more easily, and the more hidden phytoestrogen in such livestock and human food as soy products. The sources are multiple. We always forget that we live in an essentially closed (limited to the planet) but very large system, but with our current population and production techniques, we dump stuff rather profligately, never thinking in the wider sense about how it can affect our own habitat and future health. It is only recently that we have begun to look at that as we see the many signs of our effect on the planet wide habitat, and we are the only species able to appreciate that effect.
On the other hand, all creatures have impact on their environment, affect the ecology of whatever micro system they are part of. Deer affect the habitat they live in as they compete with turkey and modern fauna such a feral hogs for acorns in the fall and winter, and if there is a larger population of deer or hogs, or a lesser production of acorns due to timber harvest, all these things interact to modify a habitat and relative populations. If the deer and other critters propagate beyond a carrying capacity, there are population crashes from disease and starvation, with increased (for a time) population of scavengers taking advantage of the starved animals.
Humans just modify theirs on a larger scale than other critters, and have greater effect on species diversity. I have, in the past, considered that our wars between nations act as a population control, but it seems self defeating for a species to squander it's best and most reproductive capable young in dealing out and suffering from death and destruction, creating disease conditions that can spread world wide and leaving those who for one reason or another were not considered to be fit for war to reproduce. I dunno, a death wish gene built into the species? I have never cared much for eugenics explanations though.
CaroL
CaroL