Watch Your Back: 5 Most Incredible Discoveries of the Week

A grim stat about middle-aged white people and an amazing parking-lot excavation make the list:

• Man Killed by His Tapeworm's Cancer: Disturbing: your body becoming host to a parasite. More disturbing: getting cancer from your parasite. That's what CDC researchers say happened to a man in Colombia, whose scans revealed tumors "composed of cells that were not human." Incredibly, the tumors had come from the man's resident tapeworm.
• More Middle-Aged White People Are Dying: The US death rate has been falling for decades, but researchers say the rates for middle-aged white people have been steadily ticking up. Suicides and deaths from drug overdose and alcohol abuse are apparently to blame. And the beginning of the uptick coincides with a medical trend in the late 1990s.

• New Discovery Solves Centuries-Old Jewish Riddle: It took 100 years of searching and 10 years of digging to find what Jewish archaeologists are calling "a dream come true." The Greek ruler Antiochus IV Epiphanes—the "villain" of Hanukkah—built the Acra 2,000 years ago to exert control over Jerusalem. The Israel Antiquities Authority now says the ruins of the fortress have finally been found—under a parking lot.
• Diamonds Way More Common Than Thought: Researchers at Johns Hopkins University are out with some intriguing news about diamonds: They appear to be far more common than thought. The catch is that they're so deep in the earth and so small, this won't affect prices at the jewelry store. The study suggests an entirely new way diamonds can be formed.
• Your Cat May Really Want You Dead: Cats are fluffy little creatures that like playing with string and lying on their backs for a tummy rub. They're also neurotic predators that share certain aggressive personality traits with African lions, per a University of Edinburgh study. That means they'd maybe want to kill you, save for the one thing holding them back.

Click to read about more discoveries, including two old burial vaults under New York City. (More discoveries stories.)