A scientist's new report this week shows that the second of two greatest tell-tale natural indicators of human mass extinction exists. The first had already been proven. The new findings published Wednesday are a clarion call to humanity.
Frogs are bio-indicators, meaning they indicate the ecosystems's health. Because frogs are most often the first animals to react to biological hazards, they are a helpful warning to humans, for humans to take positive action. The Australian scientist's recent discovery about frogs is alarming, to say the least.
“About 200 frog extinctions have occurred and hundreds more will be lost over the next century, so we are on pace to create a mass extinction,” according to the study report by scientist John Alroy.
Alroy, the research paper author and associate professor at Macquarie University's Department of Biological Sciences, analyzed international data on declining frog populations in a paper published in Proceedings of the National Academy of Sciences of the USA on Tuesday.
Dr Alroy found 200 of the world's 6355 known frog species became extinct within 30 years, from the 1960s to the 1990s.
Everything is getting worse for frogs," he said, and the reason is not the usually blamed culprit, global warming, according to Alroy. While global warming might be contributing to the declining frog populations, Dr Alroy said most of the species losses were due to other factors.
"The losses are coming from the introduction of invasive species, the spread of a fungus called BD (Batrachochytrium dendrobatidis), habitat destruction and, potentially, pollution," he said.
The largest species loss has been in Central America and Brazil, where populations have been devastated by the BD fungus, according to the Canberra Times.
How do frogs demonstrate human extinction? Frog skin is very porous and permeable. This allows environmental toxins to be absorbed within frogs' fatty tissues. These poisons bioaccumulate – becoming concentrated and stored in the frogs' fat cells. As tadpoles, frogs spend part of their lives in water. Frogs' soft, jellylike eggs readily absorb pollutants along with moisture during development. Pesticides cause thyroid gland problems and mutations, such as extra limbs. Because these amphibians live terrestrially and aquatically, they indicate contamination dilemmas for land and water habitats.
Frogs are extremely sensitive to chemical pollution. Tadpoles metabolize chemicals from the water and release them in their urine. The chemicals are then reabsorbed from the same water, much like a human fetus reabsorbs wastes. Scientists study environmental effects on frogs to understand how the environment affects humans. Chemical contamination causes mutations and cancers in frogs.
Endocrine disrupting toxic chemicals have been found to feminize male frogs and cause homosexual behavior.
“From the carpets in our living rooms to the liners of our canned goods we’re exposed to manmade chemicals every day,” Steve Curwood commented in a 2011 It’s Living on Earth program (http://loe.org/shows/segments.html?programID=11-P13-00001&segmentID=7 ) conducted by Ashley Ahearn. “We use synthetic chemicals for everything, from plastics to pesticides. They eventually make their way from our farms, households or industry into the environment – and into our bodies. And they may be affecting our reproductive health – indeed, even our sexual preferences.”
Dr. Tyrone Hayes’, a biologist and University of California professor of Integrative Biology at known for research findings concluding the herbicide atrazine is an that de-masculinizes and feminizes male frogs, advocates for critical review and regulation of pesticides and other chemicals possibly causing adverse health effects. One of Dr. Hayes’ PhD students noticed male-on-male copulation in a tank treated with atrazine – America's second most commonly used herbicide. Hayes began collecting data and exposed frogs to the same level of atrazine that the Environmental Protection Agency says is safe for drinking water, and he kept other frogs atrazine-free. His research showed atrazine exposure made frogs 7 times more prone to homosexual behavior and 10 percent actually feminized.
Hays showed to Curwood s frog that looked like a female on the outside, but on the inside, it had large testes - equivalent of a man with a uterus. The male frogs were producing eggs and having babies. And there are consequences. Dr. Laurence Baskin is a pediatric urologist with the University of California, San Francisco and practices part-time at the Oakland Children’s Hospital. He’s performing back-to-back surgeries to correct hypospadias – the second most common birth defect in the country behind heart disease. About one in 125 to one in 250 newborn males has a genitalia abnormality that can be described as hypospadias – penile curvature, abnormal urethra and abnormal foreskin.
It is not, however, only reproductive health impaired by endocrine disrupters, not are endocrine disrupting chemicals only showing up in feminized frogs. Almost 100 percent of the human population has endocrine disrupters today, according to the Centers for Disease Control.
With loss of habitats to development, weather changes, logging and pollution, the entire ecosystem is impacted. Frog research tells humans when waters are polluted and warn how environmental changes affect cell development.
Though not as effective as the other top health indicator of our planet, bats, also facing extinction, frogs help insect control. They are a food source to many carnivorous species. They are, therefore, essential for maintaining balanced ecosystems.
“Frogs have survived in more or less their current form for 250 million years, having survived countless ice ages, asteroid crashes, and other environmental disturbances, yet now one-third of amphibian species are on the verge of extinction. (SavetheFrogs.com)
“This should serve as an alarm call to humans that something is drastically wrong in the environment.”