Diversity and naming

Look around and you see plants, insects, birds and animals, and there are many more living things you cannot see, like bacteria. Explore a bigger area, say deep into a forest, and you find still more kinds. Each different kind of living thing is a species. About 1.7 to 1.8 million species are known and described so far, and new ones keep being found as new places are explored. The number and variety of living things on Earth is called biodiversity.

Now think of rice. In one state it is chawal, in another bhaat, in another arisi. And a word that means rice in one place may mean something else, like a potato dish, in another. If scientists from India, France and Korea want to talk about the same plant, local names will only confuse them. Some living things have no local name at all, because nobody uses them.

So every organism is given one name used all over the world. Giving this name is nomenclature. It is possible only after identification: you must first describe the organism correctly and know exactly what it is. The rules for naming are set by agreed codes: ICBN (International Code for Botanical Nomenclature) for plants and ICZN (International Code of Zoological Nomenclature) for animals. A scientific name is never used for two different species.

Each scientific name has two parts, like a first name and a surname. The first part is the genus (generic name); the second is the specific epithet (species name). This two-part system is binomial nomenclature, given by Carolus Linnaeus.

The rules:

• Names are in Latin (or made Latin-like).
• When printed, the name is in italics. When handwritten, each word is underlined separately.
• The genus begins with a capital letter; the specific epithet begins with a small letter.

Mango is aam, ambi or keri in different places, but its scientific name is Mangifera indica: Mangifera is the genus, indica the species. You may see it written Mangifera indica Linn. The short author's name at the end shows that Linnaeus first described it. Other examples: lion Panthera leo, tiger Panthera tigris, housefly Musca domestica, wheat Triticum aestivum, human Homo sapiens.