Dear Arielle,
Language changes all the time. Words get new meanings. New words get made up.
I talked about it with my friend Rich Zack. He’s an insect scientist at Washington State University. He does taxonomy. That’s the science of naming and classifying living things.
The way language changes is amazing—and skibidi. It’s neat that language morphs as we use it. But that can limit how well we understand each other. Some readers might see “skibidi” and think I passed out and hit random keys.
That’s the main reason scientists use Latin or ancient Greek to name things. They’re dead languages. Nobody uses them to have everyday conversations anymore.
“Because they’re dead languages, the meanings of words won’t change,” Zack said. “When you’re naming a species, that’s important. If I name something ‘big black fly’ in Latin, it will always be ‘big black fly.’”
Sometimes people call very different critters by the same common name—which can be confusing. That’s why scientific names are useful. All three of these are sometimes called daddy long legs. From left to right: spider from the group Pholcidae, non-spider arachnid from the group Opiliones, fly from the group Tipulidae, © Rupert Lees © abedalsalam © Kevin Metcalf
In the 1700s, biologist Carl Linnaeus wanted an orderly system to sort living things. Back then, Latin was still used by people in the West for official stuff—like science, religion and government. So, it was the obvious choice for naming organisms.
Linnaeus came up with the system still used today. It’s called binomial nomenclature.
The idea is to give each organism a name with two parts.
The first word is the genus. That’s a group of related species. They have similar traits and a common ancestor.
The second word is the species. Organisms of the same species are very similar. They share most of their genes. They can probably have babies together.
Scientific names use italics. The genus name starts with a capital letter. The species name is lower case. Sometimes the last name of the person who named it comes after that.
Like this: Musca domestica Linnaeus
That’s a common house fly. It belongs to the genus Musca—or “fly” in Latin. Its species name is domestica—meaning “of the house.”
The scientific name for house flies has stayed the same since Linnaeus described them in 1758. Fun fact: If an insect is an actual fly, “fly” is written as a separate word. Like house fly or drone fly. If an insect is not really a fly, the “fly” in its name will be stuck to another word. Like butterfly or stonefly. Richard Fuller
Back in the 1700s, Linnaeus and other scientists didn’t know about evolution or DNA. They mostly sorted organisms based on how they looked. That made for some good ideas. It also made for some seriously bad ideas—like harmful ways to sort people based on skin color or body differences.
Binomial nomenclature was one of the good ideas.
“The goal is to develop a system of relatedness that we can backtrack to the primordial swamp,” Zack said. “Even though Linnaeus didn’t know he was fitting into that system, he was. Then evolution came along and justified the system he had created without him even knowing how that worked.”
Now scientists use all kinds of data to sort organisms. That includes what they look like and how they live their lives. It includes what DNA tells us about their histories and relatives. Sometimes new information means moving species around. You can tell that’s happened if the last name is in parentheses.
Like this: Eristalis tenax (Linnaeus)
This drone fly once belonged to the genus Musca—just like the house fly. A later scientist grouped the flies that mimic honey bees together. Drone flies look like male honey bees, so they fit better in the new genus Eristalis.
Drone flies moved to a new genus when scientists learned more about them. You should definitely check out their babies aka rat-tailed maggots. © Drepanostoma
Like language, our classification system changes to make space for new and better information. But the Latin words remain reliably the same.
Sincerely,
Magister Universus