Do humans kiss for health benefits? Maybe. An immunology study suggested that kissing is a way of passing on immunity to certain viruses. A nasty bug called cytomegalovirus is dangerous when introduced to pregnant women. The virus can cause birth defects or death, so it is important that women not be exposed to cytomegalovirus while they are pregnant. But what if they are exposed to it before they are pregnant? Then they have a chance to build up immunity to it. Thank you, antibodies.
So if a man finds a woman attractive and might want to impregnate her, it is in his best interest to have her build up some antibodies first to protect their offspring. Enter kissing. Passing germs through saliva is a great way to build up antibodies, and so kissing may have been kept in the selective lineup because it actually has some benefits for health and survival. So next time one of your little cousins says kissing is gross, tell them they are right. Germs are gross.
Keeping the family healthy is also important to other primates, who take turns grooming each other, picking dirt, insects, and leaves out of each other's hair. Practicing good hygiene keeps pathogens away from skin, and it is also a way that chimps create and maintain social ties. Instead of having your friends over to play videogames or watch a movie, next time invite them over for a grooming party. It is sure to be a big hit.
Approximately 99.9% of songs played on the radio are about finding a mate or losing one. Well, musicians don’t always call them mates, but you know that is what "my boo" and "sexy lady" really are if you boil it down. If pop culture is any indication, mating behavior is an important business. Since modern technology means most of us have plenty of food and don’t have to worry about shelter, mating is the only thing left to sing about.
We see a couple common animal behaviors in modern pop songs:
Animal behavior can make conservation difficult. Those darn animals that just won’t mate make it hard for conservationists to help them. But what’s the deal? Why do animals hate breeding in captivity? Sometimes, imprinting is the culprit. Pandas are notoriously stubborn about mating in captivity. The London Zoo’s panda Chi Chi imprinted on the humans that raised her, so she refused to mate with her own species and instead attempted to mate with a human zookeeper. Sad panda.
Panda. Image from here.
A similar problem with imprinting occurred in endangered whooping cranes that were raised by sandhill crane foster parents. The whooping cranes imprinted on the sandhill cranes and then would not mate with other whooping cranes. Now, conservation biologists expose baby whooping cranes to sounds of their own species, so they form a mating bond with members of their own species as adults.
An endangered whooping crane.
Schooling behavior in fish also causes conservation problems. Fish that form big schools are easier to catch than solitary fish, and many species that school (sardines, anchovies and other small fish) are being overfished. That is, humans catch them at rates faster than new fish are born, causing fish shortages. The unfortunate thing is that it is not just our fish that we are eating too much of—ocean predators like dolphins, whales, and seabirds depend on these fish for their own food. Dolphins can’t exactly go to the grocery store when their refrigerators are getting low.
In the mid-1900s, California’s sardine fishery collapsed; the Atlantic fisheries have gone through turbulent times as well. Cod was so overfished in the 1970s and 1980s that in 1992, the Atlantic northwest cod fishery completely collapsed and still has not recovered. Currently, scientists recommend that fisheries leave half of what they normally catch in the ocean to protect marine life and ensure the longevity of the fisheries. As with most conservation issues, doing what is best in the long-term has huge economic impacts in the short-term. Sigh.