2013 was a year with major scientific breakthroughs — the Higgs boson was finally caught, and scientists managed to coax human DNA from 400,000-year-old fossil bones in Spain.
Along the way, however, scientists also found that the world is even stranger than we thought. From penis-snatching fears to the mystery daddies in humans' genetic past, here are 10 of the most bizarre science stories of 2013.
1. Mystery ancestor
Ancient humans not only got busy with Neanderthals and Denisovans, they apparently had sex with mystery relatives as well. A new DNA analysis found that humans interbred with multiple close relatives as recently as 30,000 years ago. One scientist even described our ancient past as a "'Lord of the Rings'-type world," with many different human species living together. Let's just hope we're not part Orc.
2. Penis panic
Talk about penis anxiety. In March, anthropologists reported that penis panic was spreading through parts of West Africa. The fear, called koro, is that the genitals of the victims (mostly men, but sometimes women) are somehow shrinking into the body, or have been stolen. In an effort to stop the process, many people clamp or tie their genitals until they can seek help from shamans. The idea is that an accidental brush with a stranger caused the theft of the penis (or breast or vagina), and accusations of theft have occasionally resulted in lynchings of those accused. Koro is just one example of a mass hysteria that can spread to otherwise healthy people.
3. Quantum wormholes
Quantum mechanics, the strange laws that govern the very small, is baffling enough, but now researchers have recently raised the possibility of an even stranger phenomenon: that wormholes — shortcuts predicted by general relativity that could theoretically connect distant places in time and space — could help explain quantum entanglement, where the behavior of particles is linked across any distance. The new theory suggests that wormholes are just entangled black holes.
4. New boredom
As if the existing boredom isn't enough, scientists have discovered a new type of boredom. Researchers previously knew there were different forms of boredom, from the slightly tired and lazy form that is slightly pleasant to the more negative feeling of being stuck in a boring lecture without the ability to escape. But it turns out that many youngsters now feel apathetic boredom — a kind of disengagement akin to depression that makes them flat and incapable of emotion. This type of boredom came with a host of negative emotions, but without the antsy-ness or irritability that comes with being trapped in a boring activity.
5. Yeti uncovered?
It's the stuff of ancient lore — a mysterious shaggy beast known as the Yeti or the abominable snowman that walks upright throughout the snow-covered regions of the world. But in October, researchers claimed they had found genetic evidence to solve the mystery of the yeti. A DNA sample taken from a strange beast shot 40 years ago linked it to an ancient polar bear from Norway, raising the possibility that the Himalayas may have been home to an ancient form of polar bear that people mistook for a bipedal monster.6. Pee power
If some scientists have their way, the future could be powered by pee. Researchers have developed a new fuel cell that pumps urine to generate electricity. The idea is to power robotic devices that could monitor everything from bridge safety to air pollution using the new devices. [Super-Intelligent Machines: 7 Robotic Futures]
7. Foot orgasm
Many things — from a gym class to simple thoughts — can trigger orgasms in women, but a recent case report may take things to a new level. The case described a woman who experienced orgasmic sensations in her foot. Unfortunately, the orgasms were sudden and not spurred by lusty thoughts, making them an unwanted annoyance. Doctors suspect the "footgasms" happened after nerve damage caused by a bacterial infection led to crossed wires, with sensations from her vagina being interpreted as coming from her foot. To stop them, doctors injected an anesthetic into the foot, which seemed to do the trick.
8. New body part
After centuries of dissecting humans, you would think scientists would know all there is to know about the human anatomy. Not so. A new type of tissue was found in the eye, and was dubbed Dua's layer after its discoverer, Harminder Singh Dua, a professor of ophthalmology and visual sciences at the University of Nottingham. The structure sits at the back of the cornea, the structure in the eye that helps focus light.
9. Weird bats
2013 was the year when scientists made a stunning conclusion: Bats are just weird. Costa Rican bats use leaves as hearing aids, with the leaves amplifying sound like an ear horn. But bats also engage in lots of other weird behavior: Both male and female bats perform oral sex. In the male's case, the procedure is meant to make sex last longer. And when they're not busy using hearing aids or engaging in courtship rituals, bats use tongue erections to sop up nectar.
10. Honeybee buzz
Honeybees aren't the only workers who need a mid-afternoon boost. The insects are more likely to remember plants, such as coffee and citrus flowers, that contain caffeine. The researchers believe the bees are drawn to caffeine-laced flowers by stronger memories. That's a win-win for the plants and the bees, making the insects more effective at their jobs, while also making them more faithful pollinators for the plants.