13 Things That Don't Make Sense: The Most Baffling Scientific Mysteries of Our Time

by Michael Brooks

When Thomas Kuhn wrote The Structure of Scientific Revolutions in the early 1960s, he wanted to examine the history of science for clues to the nature of discovery. The clues led him to invent the term—now a cliché—paradigm shift.

Another cosmic problem, dark matter, was first spotted in the 1930s. Following Kuhn's template almost exactly, it was ignored for nearly forty years. Vera Rubin, an astronomer at Washington, D.C.'s Carnegie Institution, was the one to nail it down and make people deal with it. In the early 1970s, she showed that the shape, size, and spin of galaxies means either there is something wrong with gravity or there's much more matter out there in space than we can see.

bastards": bastards whichever way you looked at them.

To understand why, we have to go back to 1758, when Carl Linnaeus, a Swedish naturalist, published the tenth edition of his revolutionary book, Systema natura. Linnaeus's volume did away with the simple but unenlightening system of his day for naming and grouping biological organisms. Instead, Linnaeus grouped organisms by their shared physical characteristics. In many ways he laid the groundwork for Charles Darwin; Darwin's theory of evolution by natural selection also examined why different organisms should share certain physical characteristics and arrived at the conclusion that if things look alike they are probably related in some way. Suddenly we had the notion of a tree of life, and we could start to think about tracing our ancestors. Instead of everything having one (often very long) name, Linnaeus gave them two short ones. The first was its genus: Homo, for example. The second was the species, the subdivision that separates the members of a genus: sapiens, for example, or erectus. It was a neat system and is still biology's best. Though most of us are more familiar with gray wolf than Canis lupus, for some organisms Linnaeus's system provides the only familiar name: Tyrannosaurus rex, for example, or Escherichia (better known as E.) coli.

What if, for instance, viruses weren't always parasites? What if they evolved before life split into eukaryotes, bacteria, and archaea, but subsequently lost some of their independence? In that case they would have every right to be called alive—and they might hold clues, as many clues as the other three groups, about our Last Universal Common Ancestor (LUCA). Since LUCA is practically the holy grail of biology, it doesn't do to ignore the possibility, and the claim is not without foundation. Around half of Mimivirus's genes are unknown to science; no one has a clue what they encode. Considering how many genomes we have now sequenced, how many genes we have seen, that is rather surprising. Unless, that is, Mimivirus really is from another age. So perhaps in a bygone era Mimivirus wasn't a virus at all, but an independent, free-living organism that later fell on hard times and resorted to piracy.

Sequence your genome, and you'll find all kinds of interesting things. But among the genes that make you you, you'll also find sixty or so genes—the universal core genome—that link you to all of Earth's life. There are copies of these genes inside every biological cell on the planet, copies that write a textbook of the history of life on Earth.

The prokaryotes don't age, so researchers are now going back to studying the detailed differences between eukaryotes and prokaryotes—which means revisiting the time when the tree of life started to branch.

Senescence, the deterioration with time that leads ultimately to death, is meant to be universal in the animal kingdom. According to the standard theory, everything gets old, falls apart, and dies. It's a good theory, but, in the light of the evidence, it doesn't add up—and it fails to add up in a very tantalizing way. The turtles are vertebrates and thus closely related to us in evolutionary terms. If our molecular machinery breaks down over time, so should theirs. But it doesn't. According to Caleb Finch, a professor of gerontology at the University of Southern California, the turtles are certainly"a sharp challenge" to the idea that our senescence is inevitable. The turtles are not alone. Among the vertebrates there are several species of fish, amphibians, and reptiles that don't senesce.

The power of natural selection is reduced as a creature gets older, Medawar pointed out, so a trait that gives an advantage before the creature has reached maturity (and entered into reproduction) will be selected for; a trait whose advantage only shows after the creature has ended its reproductive life will not. The converse is also true. A gene that disables you before you reach maturity will be (negatively) selected for; it will lower the chances of the organism passing on its genes. A gene that disables the organism much later in life will be, if not exactly selected for, at least able to survive into the next generation. And here, Medawar said, is the source of senescence. It's not about the inevitable ravages of time; it's the fact that late-blooming problematic mutations—genes for cellular machinery that breaks down late in life, for example—will be passed on, and will thus accumulate in a creature's genome. In humans, Huntington's and Alzheimer's disease provide examples of this process.

Pleiotropy occurs when a single gene influences more than one trait in an organism. Antagonistic pleiotropy occurs when that influence is advantageous on one trait while problematic on another. Medawar's effect could be achieved by a single gene that confers advantage—particularly reproductive advantage—when young but creates harm in the later stages of life. This quickly became the bedrock of the theory of aging.

When a thirty-one-year-old woman called Henrietta Lacks contracted cervical cancer and had a biopsy taken, the Geys found what they were looking for. George Gey faced the cameras and held up a vial containing cells cultured from Henrietta Lacks's cancer—the most robust and fastest-growing cells scientists had ever seen."It is possible that, from a fundamental study such as this," he said, "we will be able to learn a way by which cancer can be completely wiped out." Henrietta Lacks died from the cancer on the day that Gey went on TV. But, suddenly, cancer seemed like a prizefighter on the ropes, and huge resources were channeled into finishing off the fight. Lacks's legacy, the HeLa line of cells cultured from her cancer, have become another workhorse of biology. Her cells were instrumental in the development of the polio vaccine, they have been placed at atomic bomb test sites, and have even flown on the space shuttle.

The archaea and bacteria get by without sex and don't senesce. But when the first eukaryotes, our genetic ancestors, put these organisms to work to produce energy, it was with mixed results. They happily used the energy, which has enabled us to become all that we are, but it put the mechanisms of their eventual demise—death programs, if you will (and Hayflick certainly won't)—right into the heart of their cells. Only through sexual shuffling of genes could the cells mitigate against it.

If death—or at least cell senescence—is the root of sexual reproduction, the twofold cost of sex can plausibly be offset (perhaps more than offset) by the gain that comes with death: the ATP-generating machinery at the heart of every cell. Without it, we eukaryotes wouldn't have been able to take over the world.

If all the men will only settle for the best-looking woman—and vice versa—almost everybody is going to end up unhappy. In 1962 two mathematicians worked out how, given a little compromise from everyone, you could actually make everyone happy. David Gale and Lloyd Shapley showed that if everyone compiles a ranking, in order of desirability, of potential partners, it is possible to arrange things into a stable equilibrium state. In this equilibrium, people are partnered in such a way that it is impossible to find a man and a woman from different couples who would both rather be married to each other than stay with their current partner. It's not the ideal for most individuals, but it is a satisfactory outcome for the group.

John Maynard Smith appreciated this. He took red deer as an example of where things go wrong for sexual selection theory. The powerful males get busy rutting in an exhausting, drawn-out, and impressive display of antler bashing. Often, though, the females aren't impressed and slope off to have sex with the less macho males of the herd. In a stroke of typical genius, Maynard Smith labeled them the sneaky fuckers.

Two male black swans, for example, have been observed setting up a nest together, hatching (stolen) eggs, and raising perfectly well-adjusted cygnets. Better than well-adjusted, in fact; homosexual swans have a higher success rate in raising young than do heterosexual pairs.

Roughgarden has supplemented Bagemihl's work: in her book Evolution's Rainbow she took the total number of vertebrate species observed in"nonstandard" couplings up to three hundred or so. Many more examples may yet be exposed. Bagemihl's work took a decade partly because biologists suppress reports of homosexual behaviors in the natural world. One biologist told him that admitting the animals he was observing were living in a homosexual society was"emotionally beyond [him]." Others admitted documenting homosexual behavior in animals but not publishing until they had tenure. These couplings certainly do not fit with the mainstream idea that genes, or at least organisms, are hell-bent on reproducing themselves. They do fit, however, with the idea of a social role for sex, and they fit with the idea that sexual reproduction is a spandrel, a by-product of some other phenomenon.

The Harvard University psychologist Steven Pinker probably put it best."Free will is a fictional construction," he said. "But it has applications in the real world."

Interestingly, 1785 was also the year the term placebo appeared for the first time in a medical dictionary. It was the expanded second edition of George Motherby's New Medical Dictionary, and the word, to Motherby, meant"a common place method or medicine." Though that is not particularly damning at first glance, it was most likely a negative label, meaning the medicine was trivial, or unimpressive, because the word already had a negative connotation. Placebo, which means"I will please," had come to signify insincerity, flattery, and profiteering since medieval times, when greedy churchmen would take mourners' money to sing Psalm 116 at funerals. The psalm begins, Placebo Domino in regione vivorum (I will please the Lord in the land of the living). By 1811, that negative connotation was well established; Robert Hooper published his New Medical Dictionary with an entry for placebo that read: "an epithet given to any medicine adapted more to please than benefit the patient."

As often happens, that knowledge had been gained and lost before. It was certainly known to the ancient Greeks. In 380 BCE Plato wrote Charmides, in which the Thracian king Zamolxis tells Socrates that the great error of the physicians of his day was the separation of the soul from the body. Despite doctors' best efforts, curing the body is impossible without flattering the mind, Zamolxis says. If the head and body are to be well, you must begin by curing the soul; that is the first thing. And the cure, my dear youth, has to be effected by the use of certain charms, and these charms are fair words; and by them temperance is implanted in the soul, and where temperance is, there health is speedily imparted, not only to the head, but to the whole body. Plato was right; words are powerful. If you communicate that you are doing something—if you utter what the French psychiatrist Patrick Lemoine calls the incantation—it can work wonders.

According to Ann Helm of the Oregon Health Sciences University, somewhere between 35 and 45 percent of all medical prescriptions are placebos. That estimate was made in 1985. In 2003 a survey of nearly eight hundred Danish clinicians, published in Evaluation and the Health Professions, found that almost half prescribed a placebo ten or more times per year. A 2004 study of Israeli doctors, published in the British Medical Journal, determined that 60 percent had prescribed placebos, more than half of them doing it once a month or more. Of the Israeli doctors who prescribed placebos, 94 percent said they found them to be an effective means of treatment. These are not pure placebos. The doctor can't send you to a pharmacy to get a sugar pill; after all, you might read the prescription, breaking the spell. No, doctors routinely prescribe medications that have a tiny bit of something useful in them—but its licensed use is not to treat what is ailing you.

It all kicks off with the pain-racked patients receiving something like a morphine drip. Later, after the patients have begun to associate the morphine with pain relief, you can subtly substitute saline solution for the morphine. The patients don't know their"morphine" is nothing but salt water and, thanks to the placebo effect, they report that their pain medication is still working fine. That is strange in itself, but not as strange as the next twist makes things. Without saying anything to the patients, you put another drug into the drip: naloxone, which blocks the action of morphine. Even though there is no morphine going into the patients' bodies, naloxone still stops the pain relief in its tracks; the patients, oblivious to all that has gone on, now report that they are in discomfort again. The only plausible explanation is that the drug that blocks morphine's pain-relieving power also blocks the saline's (placebo-based) pain-relieving power. Which means the saline really was doing something—it wasn't all in the patient's imagination. Or at least it means that imagination can have a physiological effect.