Rice and potato, rohu and katla: each has one scientific name, the same in Dhaka, Tokyo and London. How is that name built, and which eight rules must you follow when you write it?
1. A name in two parts
The scientific name of an organism has two parts: the first is its genus, the second is its species within that genus. The potato is Solanum tuberosum: Solanum is the genus and tuberosum the species. A name made of two parts is a binomial name, and this way of naming is called binomial nomenclature.
The aim is a single one: to identify every organism in the diverse living world, unambiguously, by a name of its own.
2. The codes and the language
A name cannot be chosen at whim; it must follow a code. A plant's name follows the International Code of Botanical Nomenclature (ICBN), an animal's follows the International Code of Zoological Nomenclature (ICZN). Each code is a printed document.
Scientific names are in Latin, so the same name is accepted throughout the whole world.
3. Linnaeus and 1753
In 1753 the Swedish naturalist Carolus Linnaeus wrote Species Plantarum, which opened an important chapter of botany. With it he introduced binomial nomenclature and defined the terms genus and species. In the same work he was the first to use the ranks class, order, genus and species.
4. Eight rules for writing a name
Rule 1 (a): the language of scientific naming is Latin, or a Latin-style form.
The young zoologist Sazid Ali Haoladar recently discovered a new frog found only in Dhaka. Its name is Zakerana dhaka. The genus is called Zakerana to honour Kazi Zaker Hossain, founder of the Zoology Department of Dhaka University.
(b) Two parts, genus first and species second: the rohu is Labeo rohita, where Labeo is the genus and rohita the species. (c) Every name must be unique, because the same name may not be used for two distinct organisms.
(d) The first letter of the first part is a capital and the rest are small; the second part is all small letters: onion Allium cepa, lion Panthera leo. (e) In print, always italics: rice Oryza sativa, katla Catla catla. (f) By hand, underline the genus and the species separately.
(g) If several scientists give the same organism different names, the rules of priority accept the earliest legitimate name, the one given by the first scientist.
(h) The scientist who first names an organism has his or her name added in short form at the end of the name, with the year: Homo sapiens L., 1758 and Oryza sativa L., 1753. Here L is short for Linnaeus.
The name starts out written wrong. Flip the switches and watch which rules break and which hold.
name labflip the switches
Rules broken, rules kept
Now build a name yourself. Each wrong pick tells you which rule it broke.
build a nameThe genus starts with a capital.
Rules for writing a scientific name
Now the other way round: six names, and which rule does each break? Think first, then tap to check.
spot the ruleCheck capitals, italics and order.
Which rule is broken?
allium cepa Rule 4 (d): the first letter must be a capital. The right name is Allium cepa.
Panthera Leo Rule 4 (d): the second part is all lower case. The right name is Panthera leo.
Catla catla Rule 5 (e): in print a name is set in italics, not upright.
rohita Labeo Rule 2 (b): genus first, species second. The right name is Labeo rohita.
one name, two organisms Rule 3 (c): a name must be unique. The same name cannot go to two distinct organisms.
Oryza sativa L. Correct. L is short for Linnaeus.
All six seen. Check the capitals, then the order, then the italics, and you catch most mistakes.
5. A history of naming
Tap the three stops and match each year to its book.
a history of namingMatch the year to the book.
Linnaeus and binomial names
1753. Species Plantarum is written. Linnaeus introduces binomial nomenclature, defines genus and species, and first uses the ranks class, order, genus and species.
1758 (English version). Homo sapiens L. is named. L is short for Linnaeus.
Zakerana dhaka. Discovered by Sazid Ali Haoladar; the frog is found only in Dhaka. The genus honours Kazi Zaker Hossain, founder of the Zoology Department of Dhaka University.
6. Check yourself
Three questions: genus first, then species.
check yourselfpick one answer
Question 1
ICBN sets the naming rules for which organisms?
Animal names follow ICZN; ICBN is the code for plants.
Right. Plant names follow the International Code of Botanical Nomenclature (ICBN).
The book says ICBN governs the names of plants.
According to the book, ICBN is the code for naming plants.
The second is about the rules.
check yourselfpick one answer
Question 2
How is a scientific name written by hand?
The rule says the genus and species are underlined separately.
Both parts are underlined, each separately.
Italics is the rule for print; by hand you underline separately.
Right. When handwritten, the genus and species are each underlined separately.
In the last one, watch how the name is built.
check yourselfpick one answer
Question 3
Which is the correctly written scientific name of onion?
Rule broken: the first letter of the first part must be a capital.
Rule broken: the second part must be written entirely in small letters.
Right. Capital first letter, everything else small: onion is Allium cepa.
All capitals breaks the rule; only the first letter is capital.
The whole note on eight cards.
cut from the notetap to turn over
Eight cards
QuestionWhat does ICBN stand for, and whose names does it govern?
AnswerInternational Code of Botanical Nomenclature; plants.
QuestionWhat does ICZN stand for, and whose names does it govern?
AnswerInternational Code of Zoological Nomenclature; animals.
QuestionIn which year and in which book did Linnaeus introduce binomial nomenclature?
AnswerIn 1753, in Species Plantarum.
QuestionWhat is the scientific name of the Dhaka-only frog discovered by Sazid Ali Haoladar?
AnswerZakerana dhaka
QuestionIn a scientific name, which letter is capital and which are small?
AnswerOnly the first letter of the first part is capital; everything else, and the whole second part, is small.
QuestionHow is a scientific name written in print and by hand?
AnswerIn print, in italics; by hand, with the genus and species underlined separately.
QuestionIf several scientists name the same organism, which name is accepted, under which rule?
AnswerThe first scientist's name, under the rule of priority.
QuestionIn Homo sapiens L., what does L stand for?
AnswerLinnaeus, the scientist who gave the name, in short form.