Reading. 3. Read the following text and explain what “species, population, habitat” mean

3. Read the following text and explain what “species, population, habitat” mean.

Defining species, populations and habitat

Various observable differences allow organisms to be put into named categories, such as elephant, giraffe or oak tree. On closer inspection these categories can be seen to be divisible into a series of smaller categories; for example, there are at least two types of elephant (the African and the Asian elephant) distinguishable by their body size (the African is larger) and various other characteristics, such as their teeth and the size of their ears. African elephants can be further divided into three separate types, based on size and habitat preferences: the forest or round-eared; the bush or large-eared and the pygmy.

That two individuals possess different characteristics does not necessarily mean that they belong to different species. A species is defined strictly as comprising all organisms that are able to interbreed and produce viable (healthy and fertile) offspring. Two closely related species may be able to produce hybrids.

It is conventional to give species a latinized specific name. The name ’oak’ is a common name, derived from the Anglo-Saxon ‘ac’ meaning fruit or acorn. The common name, the pedunculate oak, is in fact quite a good one, because it identifies an important characteristic of this species. Unfortunately, it has a second common name – common oak!

Conversely, one common name may correspond to several species. Therefore, to avoid confusion and ensure that each species has one name that is used internationally, the common or pedunculate oak also has the scientific name Quercus robur.

Incidentally, the origins of the two parts of this scientific name are quite obscure. Quercus is an old Latin namethat is used for all oak species. It is possible with the Greek for pig, choiros, because pigs are fond of acorns! The species name robur apparently means ‘strength’ or possibly ‘hardwood’ or ‘elite’, all suitable names for the oak.

A population is a group of individuals of the same species, all of which have the potential to interbreed and that live close to each other. Individuals from different populations of the same species are less likely to interbreed.

A habitat is defined as the type of environment where individuals of a species live. These habitats may occur in saltwater, freshwater or on land (terrestrial). Each habitat has its own environmental characteristics – high or low temperatures, bright light or shade, plentiful rain or draught. And species that have found a place in a habitat have inherited their own methods for surviving these conditions.

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