Evolution FTW! The Weird Stuff Animals Do to Survive
Wired Matt Simon 10.20.16.
There’s a fish that makes its home in the butt of a sea cucumber. Why? Because it worked for one crazy ancestor, and winning strategies, however unseemly, get perpetuated by natural selection. (That goes for humans too: Our mating rituals seem normal to us, but they must be hilarious to our pets.) Ultimately, life is pretty simple: Eat, don’t get eaten, and perpetuate the species—all the rest is optional. While researching my new book, The Wasp That Brainwashed the Caterpillar (out October 25), I got familiar with a wild assortment of evolution-approved survival tactics. Here are some of my favorites.
Problem: Crabs and sea snails are delicious and plentiful but heavily armored.
Solution: This crustacean has little spring-loaded punching arms that strike with over 200 pounds of force, momentarily heating the water to nearly the temperature of the sun. They can smash clamshells or disarm crabs by blowing off their pincers.
Credit: Reinhard Dirscherl/Getty Images
Credit: Thorsten Negro/Getty Images
Problem: Juicy grubs are hiding somewhere under tree bark, but how to find them?
Solution: Madagascar has no woodpeckers—which may explain the aye-aye. By tapping on branches with its long, skeletal fingers, this nocturnal primate can tell where the insect larvae are inside. It then gnaws through the wood and fishes out the grubs with its E.T.-like middle digit.
Credit: Mark Conlin/Alamy
Problem: Being a boneless tube sock of flesh puts you at the mercy of predators.
Solution: When hagfish aren’t burrowing into whale carcasses (to eat them from inside), they’re an easy mark. So if a shark bites, the hagfish instantly ejects a cloud of mucus. The slime clogs the attacker’s gills, causing it to let go and probably asphyxiate.
Credit: Jurgen Freund/Minden Pictures
Problem: The open seafloor is a dangerous place for a slender fish.
Solution: The pearlfish finds shelter in a sea cucumber’s anus. It waits for its victim to breathe (yes, sea cucumbers breathe through the wrong end) and just shimmies right in. Sometimes they go up in pairs and, scientists suspect, have sex inside. If that weren’t bad enough, the pearlfish may also eat its host’s gonads.
Credit: Dave Watts/Alamy
Problem: A short breeding season timed to produce babies when food is abundant.
Solution: The male antechinus, a shrewlike marsupial, mates so frantically with so many females in three weeks that he goes blind, bleeds internally, and drops dead. But that’s OK, for his genes will live on. And there will be fewer hungry mouths to feed.
Zombie Ant Fungus
Problem: Fungi often depend on wind to spread their spores, but a dense rain forest is windless.
Solution: The Ophiocordyceps fungus invades an ant’s body and surrounds its brain. Then it chemically mind-controls the bug up into the trees and orders it to clamp down on a leaf and anchor itself, before erupting from the ant’s head as a stalk and raining down spores on the ground below.