Agriculture
Protecting Cows—and People—from a Deadly Disease
Making the most of a meal
Flush-Free Fertilizer
Amphibians
Salamanders
Frogs and Toads
Bullfrogs
Animals
Ant Invasions Change the Rules
Copybees
Polly Shouldn't Get a Cracker
Behavior
Making Sense of Scents
The Electric Brain
A brain-boosting video game
Birds
Falcons
Rheas
Quails
Chemistry and Materials
Sticking Around with Gecko Tape
The chemistry of sleeplessness
Supergoo to the rescue
Computers
Play for Science
Toxic Dirt + Avian Flu = Science Fair Success
Earth from the inside out
Dinosaurs and Fossils
The man who rocked biology to its core
Meet the new dinos
Hall of Dinos
E Learning Jamaica
Results of GSAT are in schools this week
2014 GSAT Results for Jamaican Kids
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Earth
Giving Sharks Safe Homes
In Antarctica watch the heat (and your step)
Less Mixing Can Affect Lake's Ecosystem
Environment
A Change in Climate
Ready, unplug, drive
A Change in Leaf Color
Finding the Past
Of Lice and Old Clothes
Decoding a Beverage Jar
Fakes in the museum
Fish
Marlin
Pygmy Sharks
Lampreys
Food and Nutrition
Recipe for Health
In Search of the Perfect French Fry
Turning to Sweets, Fats to Calm the Brain
GSAT English Rules
Problems with Prepositions
Pronouns
Who vs. That vs. Which
GSAT Exam Preparation Jamaica
GSAT stars reap scholarship glory
10 Common Mistakes When Preparing for the GSAT Math Test
GSAT Exam Preparation
GSAT Exams Jamaica Scholarships
GSAT Practice Papers | GSAT Mathematics | Maths
42,000 students will sit for the GSAT Exam in two weeks
GSAT Scholarship
GSAT Mathematics
Deep-space dancers
How a Venus Flytrap Snaps Shut
10 Common Mistakes When Preparing for the GSAT Math Test
Human Body
Speedy Gene Gives Runners a Boost
Prime Time for Broken Bones
Heavy Sleep
Invertebrates
Crabs
Spiders
Millipedes
Mammals
Marsupials
Gazelle
Manxes
Parents
Children and Media
What Not to Say to Emerging Readers
How children learn
Physics
Road Bumps
The Mirror Universe of Antimatter
Hold on to your stars, ladies and gentlemen
Plants
Fast-flying fungal spores
Cactus Goo for Clean Water
Getting the dirt on carbon
Reptiles
Tortoises
Black Mamba
Copperhead Snakes
Space and Astronomy
A Galaxy Far, Far, Far Away
Catching a Comet's Tail
A Puffy Planetary Puzzle
Technology and Engineering
Searching for Alien Life
Bionic Bacteria
Sugar Power for Cell Phones
The Parts of Speech
What is a Noun
What is a Preposition?
Countable and Uncountable Nouns
Transportation
Flying the Hyper Skies
Middle school science adventures
Morphing a Wing to Save Fuel
Weather
Recipe for a Hurricane
In Antarctica watch the heat (and your step)
Arctic Melt
Add your Article

When frog gender flips

Several months ago, a California college student working at a university laboratory checked up on a group of frogs and saw some unusual behavior. Some of the frogs were acting like females — which was unusual, since at the beginning of the experiment all of the frogs were males. The student, Ngoc Mai Nguyen, says she told her boss, biologist Tyrone Hayes, “‘I don’t know what’s going on, but I don’t think this is normal.'” Nguyen, a student at the University of California, Berkeley, was working in Hayes’ laboratory. Hayes told Nguyen to keep watching — and write down what she saw each day. Nguyen knew all the frogs had started out as males. She didn’t know, however, what Hayes knew: that there was something in the water of the frog tank. That something was a popular weed killer called atrazine, and since birth the frogs had been raised in water that contained the chemical. Hayes says the experiments in his lab show that 30 percent of the male frogs that grew up in water with atrazine started to behave like females, and even send out chemical signals to attract other males.Laboratory experiments are not the only places where frogs may run into atrazine. The chemical is used as a weed killer, so it can pollute surface water downstream of the crops where it is used. In these rivers and streams, the concentration of atrazine can reach 2.5 parts per billion — the same concentration Hayes tested in his laboratory. This similarity suggests that male frogs may be turning into females in their natural habitats. The Environmental Protection Agency, or EPA, is a government organization responsible for protecting human health and the environment. The EPA defines what concentrations of certain chemicals are allowed in U.S. waterways, and the EPA has determined that up to 3 parts per billion — well above the concentration that turns male frogs into females — of atrazine is safe. If Hayes is right, even the EPA definition of a safe concentration is actually not safe for frogs. Hayes and his team have also showed that it’s not just the frogs’ behavior that changes after exposure to atrazine. Males raised in water containing atrazine had low levels of testosterone and did not try to attract females. But that’s not all: Out of 40 frogs raised in water containing atrazine, four had high levels of estrogen — a female hormone (that’s four out of 40 frogs, or one in 10). Hayes and his team dissected two of the frogs and found female reproductive organs. The other two transgender frogs were introduced to healthy males and mated with those males, producing baby male frogs. Other scientists have looked at Hayes’ work and carried out similar experiments — with similar results. Plus, researchers who study other animals have observed that atrazine affects those animals’ hormones. At least one scientist, Tim Pastoor, says Hayes has made mistakes in his study and that atrazine is safe. Pastoor is a scientist with Syngenta Crop Protection, a company that makes and sells atrazine. In an email to Science News, Pastoor wrote that Hayes’ new experiments don’t lead to the same results as Hayes’ earlier studies. “Either his current study discredits his previous work, or his previous work discredits this study,” Pastoor wrote. It’s important to know how atrazine affects the animal population. Any chemical that can change the reproductive patterns of an animal threatens that species’ survival.

When frog gender flips
When frog gender flips








Designed and Powered by HBJamaica.com™