In a study done a year ago — before Andrew Wakefield was found to be unethical, dishonest, and irresponsible, and his paper which started this whole thing withdrawn from the Lancet — it was found that one in four parents thought autism was related to vaccines. However, the study also found that of these, many felt that vaccines were still important in protecting children from disease.

While that number is high, that added part about protection is very heartening. If we can show those parents the reality that vaccines have nothing to do with autism, then maybe we’ll see the number of children suffering, and even dying, from preventable diseases drop.

After all, we can prevent measles, mumps, rubella, pertussis, HiB, and many other illnesses. But the thing is, we can also prevent ignorance. We just have to shine a light on it.

There are many who will try to extinguish that light. But we have to make sure we hold that light steady and true. It can be tiring, since the antivaxxers are loud and seemingly relentless in their zealous crusade. But we have a huge advantage on our side: we’re right. Reality will always win out, and we just have to make sure that it does so quickly, before more children lose their lives.

Tip o’ the syringe to BABloggee Randyt.

Atrazine, one of the world’s most widely used herbicides, is wreaking havoc on the sex lives of male frogs. In a new experiment, exposure to the chemical emasculated more than half of the male African claw frogs in the study, and made one in ten turn into females. The results, which were published in the Proceedings of the National Academy of Sciences, have raised concerns that the herbicide found in waterways is altering amphibians’ hormones, and could potentially have similar effects on other animals, including humans.

Biologist Tyrone Hayes studied 40 male control tadpoles along with 40 male tadpoles reared in water tainted with atrazine. The levels of the chemical matched the levels the frogs would encounter in their natural settings, and was also within the drinking water standards set by the Environmental Protection Agency. The results showed that 75 percent of male tadpoles reared in atrazine-contaminated water developed into frogs that had low testosterone levels, decreased breeding gland size, feminized laryngeal development, suppressed mating behavior, reduced sperm production and decreased fertility, while the control group showed features typically found in male frogs [AFP]. Most of these “chemically castrated” frogs were unable to reproduce.

The rest of the results were even more dramatic. Ten percent of tadpoles raised in the chemically tainted water developed into frogs with male genetics but female anatomy, and some of these were actually able to breed and produce eggs. The offspring, researchers found, were all male because both parents contributed male genes. Scientists worry that the sex-reversed males and the subsequent production of all-male offspring is skewing the sex ratio of wild frog populations, and may be contributing to the decline of frog populations worldwide.

This is not the first time that Hayes has found atrazine to be wreaking havoc on male frogs. In 2002, working on the African clawed frog, the researchers found that tadpoles raised in atrazine-contaminated water become hermaphrodites – they develop both female (ovaries) and male (testes) gonads. This occurred at atrazine levels as low as 0.1 parts per billion (ppb), 30 times lower than levels allowed in drinking water by the EPA (3 ppb) [University of California, Berkeley]. Subsequent studies in the Midwest showed that male leopard frogs living in atrazine-contaminated streams often had eggs in their testes. They also had lower testosterone levels and smaller voice boxes, which scientists presumed hampered their ability to call mates.

Other studies have found that atazine can interfere with the hormones and sexual development of fish, birds, and rats. Hayes says his new findings should raise alarms about human health. “It’s a chemical . . . that causes hormone havoc,” Hayes said. “You need to look at things that are affecting wildlife, and realize that, biologically, we’re not that different” [Washington Post].

However, Syngenta, the leading manufacturer atrazine, has disputed Hayes’ studies. Hayes responded by saying that people will have to make a final call on whether the costs of atrazine exposure outweigh its benefits: “Not every frog or every human will be affected by atrazine, but do you want to take a chance, what with all the other things that we know atrazine does, not just to humans but to rodents and frogs and fish?”[AFP].

An estimated 80 million pounds of atrazine is used annually in the United States, and it’s commonly found in ground and surface water. About 75% of stream water samples and 40% of groundwater samples contain atrazine, according to the U.S. Geological Survey. The Natural Resources Defense Council, an environmental advocacy group, detected atrazine in 90% of tap water samples from 139 water systems [USA Today]. The EPA is currently reviewing the herbicide, while several states are considering banning it all together. Atrazine is already banned in the European Union.

Join Discover Magazine on Facebook.

Related Content:
80beats: A Gentleman Frog That Takes Monogamy & Parenting Seriously
Discoblog: Endangered Frogs Encouraged to Get Amorous in an Amphibian “Love Shack”
80beats: Frogs Pee Away Scientists’ Attempts To Study Them
Discoblog: Video: How Male Frogs Kick up a Frog Froth to Protect Their Young

Image: Tyrone Hayes

Registration for The Amaz!ng Meeting 8 is now open!

Wow, what a lineup. Richard Dawkins, folks, as well as a whole passel of skeptical stars. I couldn’t help but notice I’m on that list as well. I’d better come up with a talk.

But I have a little while; TAM 8 is July 8 – 11. Maybe by then I’ll be able to open up on My Sooper Sekrit Project™. And show my tattoo!

So go and sign up. TAM 8 is the Woodstock of skepticism, and has earned that moniker. Man, it’s 5 months away and I already can’t wait!

Welcome to this week’s installment of the From Eternity to Here book club. Finally we dig into the guts of the matter, as we embark on Chapter Eight, “Entropy and Disorder.”

Excerpt:

Why is mixing easy and unmixing hard? When we mix two liquids, we see them swirl together and gradually blend into a uniform texture. By itself, that process doesn’t offer much clue into what is really going on. So instead let’s visualize what happens when we mix together two different kinds of colored sand. The important thing about sand is that it’s clearly made of discrete units, the individual grains. When we mix together, for example, blue sand and red sand, the mixture as a whole begins to look purple. But it’s not that the individual grains turn purple; they maintain their identities, while the blue grains and the red grains become jumbled together. It’s only when we look from afar (“macroscopically”) that it makes sense to think of the mixture as being purple; when we peer closely at the sand (“microscopically”) we see individual blue and red grains.

Okay cats and kittens, now we’re really cooking. We haven’t exactly been reluctant throughout the book to talk about entropy and the arrow of time, but now we get to be precise. Not only do we explain Boltzmann’s definition of entropy, but we give an example with numbers, and even use an equation. Scary, I know. (In fact I’d love to hear opinions about how worthwhile it was to get just a bit quantitative in this chapter. Does the book gain more by being more precise, or lose by intimidating people away just when it was getting good?)

In case you’re interested, here is a great simulation of the box-of-gas example discussed in the book. See entropy increase before your very eyes!

Explaining Boltzmann’s definition of entropy is actually pretty quick work; the substantial majority of the chapter is devoting to digging into some of the conceptual issues raised by this definition. Who chooses the coarse graining? (It’s up to us, but Nature does provide a guide.) Is entropy objective, or does it depend on our subjective knowledge? (Depends, but it’s as objective as we want it to be.) Could entropy ever systematically decrease? (Not in a subsystem that interacts haphazardly with its environment.)

We also get into the philosophical issues that are absolutely inevitable in sensible discussions of this subject. No matter what anyone tells you, we cannot prove the Second Law of Thermodynamics using only Boltzmann’s definition of entropy and the underlying dynamics of atoms. We need additional hypotheses from outside the formalism. In particular, the Principle of Indifference, which states that we assign equal probability to every microstate within any given macrostate; and the Past Hypothesis, which states that the universe began in a state of very low entropy. There’s just no getting around the need for these extra ingredients. While the Principle of Indifference seems fairly natural, the Past Hypothesis cries out for some sort of explanation.

Not everyone agrees. Craig Callender, a philosopher who has thought a lot about these issues, reviewed my book for New Scientist and expresses skepticism that there is anything to be explained. (A minority view in the philosophy community, for what it’s worth.) He certainly understands the need to assume that the early universe had a low entropy — as he says in a longer article, “By positing the Past State the puzzle of the time asymmetry of thermodynamics is solved, for all intents and purposes,” with which I agree. Callender is simply drawing a distinction between positing the past state, which he’s for, and trying to explain the past state, which he thinks is a waste of time. We should just take it as a brute fact, rather than seeking some underlying explanation — “Sometimes it is best not to scratch explanatory itches,” as he puts it.

While it is absolutely possible that the low entropy of the early universe is simply a brute fact, never to be explained by any dynamics or underlying principles, it seems crazy to me not to try. If we picked a state of the universe randomly out of a hat, the chances we would end up with something like our early universe are unimaginably small. To most of us, that’s a crucial clue to something deep about the universe: it’s early state was not picked randomly out of a hat! Something should explain it. We can’t be completely certain that such an explanation exists, but cosmology is hard enough without choosing to ignore the most blatant clues that nature is sticking under our noses.

This chapter and the next two are the heart and soul of the book. I hope that the first part of the book is interesting enough that people are drawn in this far, because this is really the payoff. It’s all interesting and fun, but these three chapters are crucial. Putting it into the context of cosmology, as we’ll do later in the book, is indispensable to the program we’re outlining, but the truth is that we don’t yet know the final answers. We do know the questions, however, and here is where they are being asked.

According to a new study in the Proceedings of the National Academy of Sciences, chivalry just depends on how much time you’ve got.

That was the conclusion Benno Torgler and colleagues arrived at by studying two of history’s most famous shipwrecks: The Titanic, where social norms seem to have prevailed and women and children had a better chance of surviving, and the Lusitania, where they did not. The rapid sinking of the Lusitania appears to have triggered the selfish instinct for survival in its passengers, while the slow sinking of the Titanic may have allowed altruism to reemerge.

More than 1,500 people died when the Titanic struck an iceberg in 1912 and sank over the course of three hours in the freezing waters of the North Atlantic. In their analysis, the researchers studied passenger and survivor lists from both ships, and considered gender, age, ticket class, nationality and familial relationships with other passengers. The differences emerged after a closer look at the survival rates [The New York Times]. Children aboard the Titanic, researchers say, were about 15 percent more likely to survive than adults, and women had more than a 50 percent better chance than men to make it out alive.

But while the Lusitania disaster occurred only three years after the Titanic, researchers say that the passenger reaction was quite different. The Lusitania took just 18 minutes to sink on 7 May 1915, torpedoed by a German U-boat just off Kinsale in Ireland, on a voyage between New York and Liverpool: 1,198 died, and it was literally survival of the fittest among the 639 who escaped [The Guardian]. People between the ages of 16 and 35 had the best chance of surviving the Lusitania, the scientists say, not only because there was so little time, but also because the escape was hazardous and the lifeboats rocked violently.

There are many confounding factors in a disaster, but Torgler argues that time was the key. With the Titanic sinking so slowly, he argues, social norms reemerged: Not only did women and children fare better, but upper class people were more likely to survive the Titanic wreck than the Lusitania, which devolved into a mad dash to the lifeboats. However, psychologist Daniel Kruger says that leadership could play a large role, too. The Titanic crew was more successful in maintaining order than the crew of the Lusitania. “People might be in a state of panic, but if they are reassured there is a system in place, they might be more likely to go along with contingency plans,” Kruger said [Los Angeles Times].

The life-and-death drama of events like the Titanic and Lusitania provide researchers a window to further figure out how people behave under pressure. Torgler and his colleagues are studying the reactions to more recent disasters — namely in the use of text messages, including those sent by people trapped during the World Trade Center attacks on Sept. 11 [The New York Times].

Related Content:
DISCOVER: The Titanic’s Ruin
DISCOVER: The Titanic’s Revenge
80beats: Next Global Warming Victim: Centuries-Old Shipwrecks
Discoblog: The Navy’s Old Ships Get a Second Life… As Fish Residences

Image: National Archive