Free The Darwin Awards 4: Intelligent Design by Wendy Northcutt

percent of males ever find one female, let alone two. Even if a redback male did get lucky twice, he would be functionally sterile, because his palps are damaged during mating and emptied of sperm. Cannibalized, the male doubles his “paternity benefits”—offspring. The female he inseminated can store his sperm for the rest of her life, potentially producing thousands of offspring. Generation after generation, this paternity advantage has cemented risky behavior in males. Each suitor performs the same suicidal somersault, trading his life for more offspring.
    Widow spiders aren’t the only animals with a penchant for cannibalism. Several species of praying mantis also eat their mates. Mantises are aggressive hunters, occasionally catching much larger prey, including hummingbirds. (One biologist often says the only thing mantises pray for is a good meal.) Most species only cannibalize mates regularly in captivity, but one species in particular deserves its bloodthirsty reputation. The European Mantis ( Mantis religiosa ) is a common, two-to three-inch green mantis with an uncommon appetite. In the wild, the female eats a third of her partners. She eats even more in the lab when the males can’t escape. She is so voracious that the male European mantis forgoes mating displays in favor of surprise. No foreplay for her! He sneaks up on the female from behind, so she won’t get any ideas about his juicy head. If he can get close enough, he’ll leap onto her back and begin to mate.
    If the female spots her mate’s head during the process, she’ll snatch it and begin to dine. The decapitated male only has one goal at this unfortunate juncture. He thrashes wildly, and though headless, manages to mate with her. Mantis females eat all parts of the male they can reach. At least themale redback spider’s death is voluntary. Cannibalism in the European mantis shows no sign of male buy-in. He makes a tremendous effort to avoid being eaten, his wariness a good indication that sexual cannibalism has shaped the evolution of his behavior.
    Sexual cannibalism may be rare and extreme, but it has evolved several times in the animal kingdom. For species like the redback spider and the European mantis, reproduction trumps even death. It always does—natural selection ensures that the fittest genes are perpetuated, even when the process is painful for the participants. So when the male redback spider gives his life as a snack, he can honestly claim: “my genes made me do it.”
     
    Further reading:
     
    Andrade, M.C.B. 2003. “Risky mate search and male self-sacrifice in redback spiders.” Behavioral Ecology, 14: 531–538.
     
    Lawrence, S.E. 1992. “Sexual cannibalism in the praying mantid, Mantis religiosa : a field study.” Animal Behavior, 43: 569–583.
     
    Johns, P.M., and Maxwell, M.R. 1997. “Sexual cannibalism: who benefits?” Trends in Ecology and Evolution, 12(4): 127–128.
     
    Additional References:
     
    Andrade, M.C.B., and Banta, E.M. 2002. “Value of remating and functional sterility in redback spiders.” Animal Behavior, 63: 857–870.
     
    Andrade, M.C.B. 1996. “Sexual selection for male sacrifice in the Australian redback spider.” Science, 271: 70–72.
     
    Mukerjee, M. October 1995. “Giving your all.” Scientific American.

    Now that we’ve read about the deadly dangers that female insects pose to their males, let’s turn the tables, and watch female humans place themselves in equally deadly predicaments. It is with great pleasure that I introduce these stories about feminine wiles….
 
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    Video of the male redback spider’s suicidal somersault:
     
    www.DarwinAwards.com/book/spider.html
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D ARWIN A WARD : M ILITARY I NTELLIGENCE
    Unconfirmed by Darwin
     
    1970 S , N ORTHERN I RELAND
     
     
    Back in the late seventies, intelligence units in Northern Ireland were issued exploding briefcases to carry sensitive documents. These briefcases were lined with oxygen bricks. To arm