Systematics

A

To study the diverse life forms that share our planet and to effectively communicate our findings, we need to organize our knowledge of them.

The scientific study of the diversity of organisms and their evolutionary relationships is called systematics. An important aspect of systematics is Taxonomy, the science of naming, describing and classifying organisms. The term classification means ordering organisms into groups based on their similarities or relationships.

B

Different methods of classification have been used throughout history. Animals, for example, were classified by St. Augustine in the fourth century as useful, harmful and superfluous to humans. During the Renaissance scholars began to develop categories based more on the characteristics of the organisms themselves. These categories were arranged roughly in order from simple to complex organisms.

C

Carolus Linnaeus in the mid-18 century developed a binominal system of nomenclature in which each species is given a unique two-part name. The "cuckoo flower" and the "lady`s smock" (Сердечник луговой) are two common names for the same wild plant and this could lead to confusion. However, if the botanical name, Cardamine pratensis, is used, there is no chance of error. The Latin form of the name allows it to be used in all the countries of the world.

"Binominal" means "two names". The first name gives the genus and the second gives the species.

D

Linnaeus also made a system for arranging species to a hierarchy of groups. His system has proved to be flexible and adaptable to new biological knowledge and theory. Most biologists currently use a hierarchical system that includes

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species.

E

In 1937 the French marine biologist Edouard Chatton suggested the term procariotique ("before nucleus") to describe bacteria, and the term eukariotique ("true nucleus") to describe all other cells. This dichotomy between prokaryotes and eukaryotes is now universally accepted by biologists.

F

In 1969 R.H.Whittaker proposed a five-kingdom classification, which is now favoured by many biologists. Whittaker classified organisms in 5 Kingdoms: Animalia, Plantae, Fungi, Protista, and Prokaryota or Monera.

G

The evolution of systematics reflects the creative and dynamic process of science. Systematists have been very responsive to new data, and so classification of organisms is a challenging and continuously changing process.

11. Match a title to the paragraph.

	Binominal system
	Hierarchy
	Five Kingdoms
	Changing process
	Prokaryotes and eukaryotes
	Methods of classification
	About terms

12.Answer the questions to Text 1.

1. What`s the difference between systematics and classification?

2. What does "binominal system" mean?

3. Why do scientists use Latin when naming species?

4. What`s the difference between prokaryotes and eukaryotes?

5. Do you agree with a five-kingdom classification?

13. Read the texts using your dictionary.

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