The duck-billed platypus looks and acts like an animal with an identity crisis. It swims a bit like a duck and walks like one, too (on those webbed little feet), but it's certainly no bird. It lays eggs, as if a bird or reptile, yet it nurses its young like the mammal that it is. Now, it turns out the animal looks like a hybrid even at the most minute level, its DNA. Along with today's announcement that the platypus's genome has been sequenced comes the revelation that its genes reflect its odd ancestry.

It's not that the platypus has mixed ancestry, so it's not a true hybrid. Rather, it's thought that the ancestors of the platypus evolutionarily diverged from the rest of the mammals about 166 million years ago, so it retains some of the genetic and physical characteristics that other mammals may have had at that time but have since lost.

A diet high in fat—extremely high in fat, that is—has just been shown in a clinical trial to cut seizure frequency in children with severe, drug-resistant epilepsy. It's not a cure, and it's not an easy treatment to stomach, but it works, British researchers reported Friday in the journal Lancet Neurology.

Dr. Atkins himself might have gagged on the therapeutic regimen, which is called the ketogenic diet. It's so fatty that carbohydrates and protein combined aren't permitted to account for more than 25 percent of total calories. Each patient needs to have his or her diet specially designed by a dietitian, who calculates how many calories of fat, carbs, and protein need to be eaten each day. By comparison, fat can constitute "only" 50 percent of the caloric energy in the Atkins diet.

The Interior Department has barely two weeks to issue a ruling on whether the polar bear qualifies for protection under the Endangered Species Act, a federal judge decided this week. As the New York Times reports, Judge Claudia Wilken of Oakland, Calif., "rejected the government's contention that the case was too complicated to decide before June 30." Environmentalists argue that the melting of the Arctic icecap, which is reducing the polar bear's habitat, represents a serious threat to the species. The Times continues:

At a news conference earlier this month, the White House spokeswoman, Dana Perino, said environmentalists were inappropriately trying to use existing environmental laws, like the Endangered Species Act and the Clean Air Act, to address climate change. The result, Ms. Perino said, would be a "regulatory train wreck."

In my last post, I called eFluxMedia on its erroneous coverage of five-year-old medical research. The publication calls itself "an online newspaper that aims to offer a public service. Its main purpose is to inform its readers correctly, impartially, and continually, according to journalistic principles." It reported today that masturbation reduces men's chance of developing prostate cancer. The story is time-stamped "13:40, April 24th, 2008."

The finding it then goes on to describe was reported by other news organization in July of 2003. In fact, eFluxMedia writer Anna Boyd paraphrased a BBC.co.uk report and a New Scientist story and pulled quotes from both of them (with attribution). Oddly, Boyd did not mention the timing of those reports or of the original medical study, referring to it only as the "latest study in this field." As I just reported, that study is no longer the latest study in the field. A very similar finding essentially confirmed the 2003 study the following year.

E-mails addressed to Anna Boyd and sent to several addresses at eFluxMedia.com were not immediately returned; at least one bounced back. A telephone number could not be found on the publication's website. If I hear back, I'll let you know.

What happened to the concept that news reporting should be about recent events? The Internet is suddenly abuzz with "news" reports of a five-year-old Australian study that suggested that masturbating protects men against developing prostate cancer.

I called out the erroneous reporting yesterday. Since then, eFluxMedia has made the same journalistic mistake that Fox News and others made earlier this week. (Either that, or eFluxMedia intentionally passed off as news a story that its staff realized was old. More on that in a forthcoming post.)

The animals rights group People for the Ethical Treatment of Animals announced this week that it will offer a $1 million reward to the inventor of laboratory-grown, tastes-just-like-chicken (or beef or pork), no-animals-were-harmed-in-the-making-of-this-burger meat—should someone come along who can claim that mantle. The Associated Press quickly gobbled up the news, and Time offered its take yesterday. PETA lays out its rationale as follows: "More than 40 billion chickens, fish, pigs, and cows are killed every year for food in the United States in horrific ways. Chickens are drugged to grow so large they often become crippled, mother pigs are confined to metal cages so small they can't move, and fish are hacked apart while still conscious—all to feed America's meat addiction. In vitro meat would spare animals from this suffering. In addition, in vitro meat would dramatically reduce the devastating effects the meat industry has on the environment."

The environmental argument holds considerable weight. Large quantities of water, grain, antibiotics, and energy are used to produce hamburgers, and animal waste is a pungent and dangerous problem of its own. If meat could be grown efficiently in vitro, the benefits to society could be many. But not everyone is fully on board: Calling yesterday for a "measured approach," the New York Times editorial board opined that it "will be a barren world if the herds and flocks disappear in favor of meat grown in a laboratory tank." In the long run, I wonder if our omnivorous species has any choice.

Recent reporting you may have read on the health effects of masturbation is wrong. I don't mean morally; I mean journalistically. PlanetOut reported on Monday that "BBC News reported on Wednesday" that masturbating frequently may reduce a man's risk of prostate cancer. Masturbating may or may not affect one's cancer risk, but the only BBC report I can find on the subject is dated July 16, 2003—and it contains statistics that are identical to those cited by PlanetOut. (For what it's worth, that day was indeed a Wednesday, according to this online tool.)

Moreover, the Australian organization named by both news outlets, the Cancer Council Victoria, does not appear to have any recent press release on masturbation or ejaculation, though it does have one dating to July 2003. (A phone call to the Cancer Council, placed at 4:27 a.m. local time, went unanswered.) A search of PubMed.gov, a database of published medical studies, turned up only one study about ejaculation (and one letter to an editor) coauthored by Graham Giles, the researcher quoted by PlanetOut.

"Ballistic re-entry" is a pleasant-sounding euphemism for what happened to Russia's Soyuz spacecraft on Saturday, but from press accounts like this one by MSNBC, it sounds as if the capsule basically crash-landed. What sort of questions does this incident raise for the safety of continued space exploration?

In other space exploration news, accomplished astrophysicist and cosmologist Stephen Hawking stated last night that life probably exists on other planets but that it may not be intelligent enough to communicate with us. "Primitive life is very common, and intelligent life is fairly rare," he said, according to the Associated Press. "Some would say it has yet to occur on Earth."

Hawking endorsed human exploration of space, saying, "If the human race is to continue for another million years, we will have to boldly go where no one has gone before."

Bisphenol A, a major ingredient in polycarbonate plastic that's also used to preserve canned foods, is getting lots of bad publicity this week. But polycarbonate isn't the only kind of plastic that has health experts concerned; plasticizers called phthalates make some of them nervous, too.

Some scientists and parents have been worried for years about these chemicals (pronounced THAL-ates), which make certain plastics like vinyl pliable and are also used as solvents in cosmetic products. Groups like Greenpeace have been calling for bans of vinyl pacifiers and toys for at least a decade. (And here I thought toxic toys were the recent problem!)

Can a man OD on an ED drug? Yes, according to doctors in Rome who treated a patient after he popped two of the pills at once. Their case report links the 70-year-old man's intracerebral hemorrhage, a kind of stroke, to his decision to take 40 milligrams of tadalafil (Cialis)—twice the dose he had been prescribed and four times the standard dose of that erectile dysfunction drug. He took the pills, they write in today's issue of Neurology, "1 hour before onset of his acute headache and...his symptoms worsened moderately during his sexual intercourse."

It's just a single case, of course, so it doesn't prove cause and effect. And the doctors who treated and released the man identified only three previous medical reports that have linked ED drugs to intracerebral hemorrhage, suggesting that it is an extremely rare side effect. Still, those reports have implicated both sildenafil citrate, which is the active ingredient in Viagra, and vardenafil, which is in Levitra. So, none of the three drugs in that widely used class of ED medications is off the hook.

Moral of the story: One dose, good. Two, too many.

Clever acronyms abound in the world of medical science. Some trials bear names like AVIATOR, SHOCK, and AWESOME and not just because researchers like showing off their verbal virtuosity. A couple of years ago, a study—called ART in Medicine, naturally—showed that acronym-named studies get cited more frequently than studies of equal quality that don't have catchy handles. An upshot of that favoritism is that doctors may overlook some important medical findings while giving others more than their fair share of attention. That bias, in turn, could harm the practice of medicine by partially divorcing it from the evidence.

Against that backdrop, it's with mixed emotions that I call your attention to today's issue of the Journal of the American Medical Association, in which Steven Nissen of the Cleveland Clinic Foundation and his colleagues report the results of the, uh, STRADIVARIUS trial. That whopper stands for the "Strategy to Reduce Atherosclerosis Development Involving Administration of Rimonabant—the Intravascular Ultrasound Study." Phew. I need to catch my breath.

I'm eagerly awaiting the 8 o'clock hour of this Saturday evening, which has been dubbed Earth Hour, as I recently reported. The dimming of lights for one hour in more than two dozen cities around the world is an elegant protest against wasted energy and light.

I welcome after-the-fact reports and comments from readers in all participating cities. What was your Earth Hour like?

For more on light pollution, check out the Thinking Harder homepage on the topic.

I had the dubious distinction last year of being mocked (in absentia) on national TV by Jay Leno, who for some unimaginable reason found it amusing that a guy named Harder had written a news story about flaccidity.

Headline jokes aside, erectile dysfunction is a serious matter, and not just because it can threaten the health of a marriage. More than just a sexual problem, ED is often a sign that a man's life is at risk. That was the point of my report last year, and the evidence behind it has only grown stronger. On this day, the tenth anniversary of Viagra's regulatory approval by the Food and Drug Administration, I decided to look anew at that evidence. (If you're more interested in the drug itself than in the condition it treats, check out these five things about the blue pill that you might not know.)

The Washington Post's front page on Sunday carried a story on the sluggish expansion of the list of endangered or threatened species since President Bush took office. Under the current administration, the list has grown by 59 species, in every case following a request by environmental activists rather than being initiated by government officials. In the past two years, not a single species has been added.

By comparison, 231 species gained such protections under the first President Bush, who served a single term. And in 52 of those cases, according to the Post, it was administration officials, not just activists, who requested the status change. The difference between father and son is far more striking than the disparity between Bush the elder and President Clinton, whose administration extended protection to 521 species over two terms of office.

Reading Gene Weingarten's column in the Washington Post Magazine Sunday, I saw myself in the proverbial mirror—and I almost didn't recognize the face staring back.

In "Losing Face," Weingarten shares his self-diagnosis of mild prosopagnosia: "I have trouble recognizing and remembering faces," he writes. I long ago came to the conclusion that I, too, have this condition. I've never asked a doctor about it, but many a friend has been dumbfounded by my inability to recognize a given actor from one movie to the next. And more than a few acquaintances have been perplexed or offended when I've failed to recall their name on a second—or third, or fourth—meeting.