Things we didn't know before 2009
Here's a list of stuff we culled from 2009 that may have come as a surprise:
1. Domestic pigs can quickly learn how mirrors work and use them to find food.
2. Grumpy people think more clearly because negative moods trigger more attentive, careful thinking.
3. High cholesterol levels in midlife are associated with an increased risk of Alzheimer's disease and other forms of dementia later in life.
4. Analysis of Greenland ice samples shows Europe froze solid in less than 12 months 12,800 years ago, partly due to a slowdown of the Gulf Stream. Once triggered, the cold persisted for 1,300 years.
5. One mutated gene is the reason humans have language, and chimpanzees, our closest relative, do not.
6. Obesity in teenage girls may increase their risk of later developing multiple sclerosis.
7. A fossil skeleton of an Aardonyx celestae dinosaur discovered in South Africa appears to be the missing link between the earliest dinosaurs that walked on two legs and the large plant-eating sauropods that walked on all four.
8. Women who have undergone successful breast cancer treatment are more likely to experience a recurrence if they have dense breast tissue.
9. Babies pick up their parents' accents from the womb, and infants are born crying in their native dialect. Researchers found that French newborns cry in a rising French accent, and German babies cry with a characteristic falling inflection.
10. Surfing the Internet may help delay dementia because it creates stimulation that exercises portions of the brain.
11. The oldest known silken spider webs, dating back 140 million years, were discovered in Sussex, England, preserved in amber. The webs were spun by spiders closely related to modern-day orb-web garden spiders.
12. Scientists have discovered how to scan brain activity and convert what people are seeing or remembering into crude video images.
13. Pumpkin skin contains a substance that inhibits growth of microbes that cause yeast infections.
14. Hormones that signal whether whales are pregnant, lactating or in the mood to mate have been extracted from whales' lung mucus, captured by dangling nylon stockings from a pole over their blowholes as they surface to breathe. (This method could allow scientists to study whales without having to slaughter them.)
15. The higher a patient's body-mass index, the less respect he or she gets from doctors.
16. The blue morpho butterfly, which lives in Central and South America, has tiny ears on its wings and can distinguish between high- and low-pitch sounds. The butterfly may use its ears to listen for nearby predatory birds.
17. The ochre starfish or sea star pumps itself up with cold seawater to lower its body temperature when exposed to the sun at low tide. It is equivalent to a human drinking 1.8 gallons of water before heading into the midday sun, scientists say.
18. The eyes of the mantis shrimp possess a feature that could make DVDs and CDs perform better. By emulating this structure, which displays color wavelengths at all ranges, developers could create a new category of optical devices.
19. The calmest place on Earth is on top of an icy plateau in Antarctica known as Ridge A, several hundred miles from the South Pole. It is so still that stars do not twinkle in the sky because there is no turbulence in the atmosphere to distort the light.
20. The thrill of driving a sports car makes the body produce more testosterone. The findings suggest a biological explanation for why some men buy a sports car when struck by a "midlife crisis."
21. Remains discovered in China of a flying reptile named Darwinopterus could be a missing link between short-tailed pterodactyls and their huge, long-tailed descendants.
22. Bagheera kiplingi, a jumping arachnid from Central America, is the first known vegetarian spider. It eats nectar-filled leaf tips rather than other animals.
23. A massive, nearly invisible ring of ice and dust particles surrounds Saturn. The ring's entire volume can hold 1 billion Earths.
24. A new chemical compound that mimics the body's ability t o fight bacteria could be added to cleaning detergents to prevent bacterial infections in hospitals.
25. Seven new glow-in-the-dark mushroom species have been discovered, increasing the number of known luminescent fungi species from 64 to 71. The fungi, discovered in Belize, Brazil, Dominican Republic, Jamaica, Japan, Malaysia and Puerto Rico, glow constantly, emitting a bright, yellowish-green light.
26. Hormones in oral contraceptives might suppress a woman's interest in masculine men and make boyish males more attractive to her.
27. Women who revealed about 40 percent of their skin attracted twice as many men as those who covered up. Any more than 40 percent and the signal changes from allure to one indicating general availability and future infidelity.
28. Communities of 850 species of previously undiscovered insects, small crustaceans, spiders, worms and other creatures were found living in underground water, caves and micro-caverns across Australia.
29. The human body emits a glow that is 1,000 times less than what our eyes can detect.
30. If you're trying to attract a partner, an athletic body helps, but a good-looking face is more important.
31. Cockroaches hold their breath for five to seven minutes at a time through a respiratory system that delivers oxygen directly to cells from air-filled tubes. One reason they hold their breath may be to prevent their bodies from getting too much oxygen, which could be toxic to them.
32. Earth was bombarded in 2008 with high levels of solar energy at a time when the sun was in an unusually quiet phase and sunspots had virtually disappeared.
33. Scientists have discovered female eggs in the genitalia of a third of all American male smallmouth bass and a fifth of their largemouth cousins. Female bass occasionally show signs of male testes in their reproductive organs.
34. Nearly all animals emit the same stench when they die, and have done so for more than 400 million years.
35. Previously unknown molecules called hydroxyl radicals are produced by nature and are believed to act as cleaning agents that scrub away toxic air pollution in Earth's atmosphere.
36. A new species of giant rat was discovered in a remote rainforest in Papua New Guinea. At 32.2 inches from nose to tail and 3.3 pounds, it's thought to be one of the largest rats ever found.
37. Differences in body odors produced by people who are more prone to insect bites show they have lower levels of fruity-smelling compounds in their sweat than those who are resistant to mosquitoes.
38. A chemical component in broccoli can protect the lining of arteries from blockage that leads to angina, heart attack and stroke.
39. The length, curl and texture of a dog's fur are controlled by only three genes.
40. The speed of U.S Internet broadband lags far behind other industrial nations, including Japan, Finland, South Korea, France and Canada.
41. Polar bear skulls have shrunk 2 percent to 9 percent since the early 20th century. It's the result, scientists theorize, of stress from pollution and melting habitat.
42. A mysterious disease that killed off more than a third of American honeybees in 2007-08 may have been caused in part by a virus.
43. A group of deep sea worms dubbed "green bombers" are capable of casting off appendages that glow a brilliant green once detached from their bodies. The tactic is believed to be used by the worms to confuse attackers.
44. A flesh-eating pitcher plant that grows more than 4 feet long can swallow and devour rats that are lured into its slipperlike mouth to drown or die of exhaustion before being slowly dissolved by digestive enzymes.
45. An orchid on the Chinese island of Hainan gets hornets to spread its pollen by producing an aroma identical to that made by bees under attack. The hornets feed on bee larvae, so when they get a whiff of the alarm pheromone, they head to the orchids figuring bees are inside.
46. More than 350 new animal species were discovered in the eastern Himalayas, including the world's smallest deer and a flying frog.
47. The spleen is a reservoir for huge numbers of immune cells called monocyte. In the event of a serious health crisis, such as a heart attack, wound or infection, the spleen will disgorge them bloodstream to help defend the body.
48. The Amazon River is about 11 million years old and took its present shape about 2.4 million years ago.
49. A close relationship with a caregiver can give Alzheimer's patients an edge in retaining brain function over time.
50. Watermelon is more efficient at rehydrating our bodies than drinking water. It contains 92 percent water and essential rehydration salts.