Published: 19 December, 2008, 20:30
Edited: 19 December, 2008, 20:30
The feminisation of species has scientists worried. A recent report shows that fish, amphibians, reptiles, birds and mammals are giving birth to mostly female offspring, with males fading out from the scene almost completely.
According to a report recently released by the UK-based organisation CHEM Trust, which aims to protect humans and wildlife from the harmful effects of the chemical industry, frequently used chemicals lead to a widespread feminisation of vertebrate wildlife. These findings add to mounting worries about the role of hormone-disrupting chemicals in the environment and the implications for human health.
The report, which includes more than 250 scientific studies from around the world lists phthalates, used in food wrapping, cosmetics and baby powder, among other applications and PCBs, a now banned group of substances still widespread in food and in the environment and many pesticides among its list of harmful chemicals.
Ecologists discovered over 100 thousand new chemicals, the majority of which might be identified as “endocrine disrupters” as they interfere with hormones and might cause gender change.
“Urgent action is needed to control gender bending chemicals and more resources are needed for monitoring wildlife. Man-made chemicals are clearly damaging the basic male tool-kit,” said Gwynne Lyons, a former government adviser on the health effects of chemicals and author of the report.
Because of the dramatic polluting of seas and rivers, the majority of gender changes were detected among male fish, making them leaders in hermaphrodite reproduction. Half of male fish in British rivers have been found to be developing eggs in their testes. Feminising effects have now been discovered in a host of freshwater fish species in Japan and Benin, in Africa, and in sea fish in the North Sea, the Mediterranean, the Osaka Bay in Japan and Puget Sound on the US west coast.
“Feminisation of the males of numerous vertebrate species is now a widespread occurrence. All vertebrates have similar sex hormone receptors, which have been conserved in evolution,” continues Lyons. “Therefore, observations in one species may serve to highlight pollution issues of concern for other vertebrates, including humans. If we are seeing problems in wildlife, we can be concerned that something similar is happening to a proportion of human males.”
Shift in sex rations worldwide is a concern for scientists. Chemical pollution that causes gender changes might be a clue to solving this problem. Normally 106 boys are born for 100 girls but the situation is changing rapidly. Moreover, in communities heavily polluted with “endocrine-disputers” in Canada, Russia and Italy twice as many girls than boys have been born.
“Female species are considered to be more healthy and viable,” explains geneticist Pyotr Goldin. “It is kind of a hard disc that stores the most valuable information for the evolution process. Male species, on the contrary, for this process are more like an unending experiment. A woman’s mission is to store the gene pool and a man’s mission is to change it.”
So if man, being a major destructive factor for the environment, is eliminated by feminisation it might actually give a chance to a mankind; there would be nobody to ruin the Earth. Add to this the reproduction possibilities of modern science which practically exclude the male from the process, and the “strong sex” becomes redundant.
Feminisation is an obvious fact now. Scientists consider studying the problem of chemical impacts on humans further, along with strengthening control over the chemical industry, which might at least help to slow down the threatening tendency.