We like to think ourselves as independent individuals that make decisions for ourselves, without the influence of external variables. That’s not true for us humans, and it’s not true for wolves (via National Geographic):
What makes a wolf decide to strike out on its own or assert leadership of its pack? That question has long intrigued scientists. Now, a new study shows that gray wolves infected with the parasite Toxoplasma gondii are more likely to become top dog than uninfected wolves.
The finding forces us to think more broadly about what influences how animals act, says study co-author Kira Cassidy, a wildlife biologist with the Yellowstone Wolf Project, a Montana-based nonprofit that oversees research on the predators in Yellowstone National Park.
“We know that behavior is influenced by all sorts of factors, including past experiences, genetics, current circumstances, and social context,” she says. “Now we can add parasites to that list.”
Toxoplasma gondii is a single-celled parasite that infects at least one-third of the world’s human population at any given time with the disease toxoplasmosis. While the infection is usually mild, it can be fatal to the young or immunosuppressed. Toxoplasma can only reproduce in the intestines of domestic or wild cats, yet it is widespread in nature, and can infect any warm-blooded animal. It’s also famous for its ability to manipulate its hosts, most notably in making rodents reckless around house cats. (Read how Toxoplasma affects human brains.)
What out for those parasites. You might mutate into a leader.