Scientists use two names for living things. 

Scientists use two names for every living thing. 

Scientists use a special way to name living things. This is called binomial nomenclature. It is a two-part naming system. 
The first part is the genus name. It tells us which group the living thing belongs to. The second part is the specific epithet. This is a name that picks out one kind of species. For example, humans belong to the genus Homo. Our specific name is Homo sapiens. 
Before this system, names were very long. Scientists used many words to describe a plant or animal. These were called polynomial names. They were hard to remember. Carl Linnaeus helped start the modern two-part system in 1753. 
This system is very helpful. It gives every species one unique name. Common names can change in different languages. But scientific names stay the same all over the world. This helps all scientists talk to each other clearly. When writing these names, we use italics. We also always capitalize the first part. 
Scientists use a special two-part system to name every living thing. This system is called binomial nomenclature. 

Learning how this system works is like following a set of rules. First, you write both parts of the name in italics. Second, you always capitalize the first letter of the genus name. The second part, the specific epithet, stays in lowercase letters. Even if the name comes from a person or a place, it is not capitalized. For instance, the annual phlox is written as Phlox drummondii. After you use the full name once, you can shorten it. You can write just the first letter of the genus. This makes writing much faster for scientists. 
Before this system, names were much harder to use. Scientists used something called polynomial nomenclature. These names were long strings of words used to describe the living thing. 
There are many interesting facts about how these names are recorded. In scientific books, people often list the authority. This is the person who first gave the species its name. They might also include the year it was published. For example, you might see "Patella vulgata Linnaeus, 1758." This tells us Linnaeus named it in 1758. Sometimes, a species moves to a new genus. If this happens, the second part of the name usually stays the same. This keeps the name stable even when our knowledge changes.
You can see this system in your own life. Many famous names have become part of everyday speech. You might know the dinosaur Tyrannosaurus rex. You might also know the bacterium E. coli. These names are used because they are short and easy to remember. The system is governed by international codes of rules. The ICZN makes rules for animals. The ICNafp makes rules for plants, algae, and fungi. These rules ensure that every living thing has a clear, official name that scientists can trust.
Binomial nomenclature is a formal system used to name every species of living thing. This two-term naming system provides a unique, stable, and verifiable label for organisms. It is essential because common names often change depending on the language or region. A scientific name, also called a binomial or binomen, ensures scientists worldwide understand exactly which species is being discussed. 
The system works by combining two distinct parts into one name. The first part is the generic name, which identifies the genus. A genus is a group of closely related species. The second part is the specific name, or specific epithet, which distinguishes one species from others within that genus. For example, modern humans belong to the genus *Homo*. Our specific name is *sapiens*, making our full binomial name *Homo sapiens*. 
Writing these names requires following strict rules of formatting. Both parts of the name must be italicized in regular text. If you are writing by hand, you should underline the name instead. The first letter of the generic name is always capitalized. However, the specific epithet always starts with a lowercase letter. This remains true even if the name is derived from a person or a place. For instance, the annual phlox is written as *Phlox drummondii*. 
Before this system, scientists used polynomial nomenclature. These names were long strings of words used as a diagnosis or description. For example, one plant had a name describing its leaves and spikes. These names were unwieldy and became too long as more species were discovered. Gaspard Bauhin helped transition away from this in 1622 by pruning these long descriptions. However, the modern system was officially introduced by Carl Linnaeus. 
Carl Linnaeus was a Swedish botanist and physician. He began consistently using this two-part system in his 1753 work, *Species Plantarum*. Linnaeus introduced the idea that a name could simply be a unique label. It did not need to be a long description of the organism's features. Because of this, names could be derived from people or places. For example, *Tradescantia virginiana* honors the botanist John Tradescant the Younger.
In scientific works, researchers often include the authority for a name. The authority is the person who first published the name and its description. The year of publication is also often included. For example, "Patella vulgata Linnaeus, 1758" tells us Linnaeus named the species in 1758. If a species is moved to a different genus, parentheses are used. This indicates the species was originally placed in a different group.
The system is governed by international codes to ensure global agreement. The International Code of Zoological Nomenclature (ICZN) manages rules for animals. The International Code of Nomenclature for algae, fungi, and plants (ICNafp) manages the others. These codes provide stability through the principle of priority. This means the earliest published name is generally the correct one. If a species is moved to a new genus, the specific epithet usually stays the same. This keeps the identity of the species constant even as scientific knowledge evolves.
Binomial nomenclature is highly efficient and widely used. It is much shorter and easier to remember than the old polynomial system. Some scientific names have even entered common speech. You may recognize *Tyrannosaurus rex*, *E. coli*, or *Aloe vera*. While there are occasional problems, such as homonyms where names are duplicated, the system remains the standard. It connects naming to the broader field of taxonomy, which is the ordering of items into groups based on similarities.
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