Biodiversity and Genetic Resources

Read the text and answer the questions that follow.

Reading

Pre-reading

Listening task

Talking Points

What do you know about polar bears?

Do you know if the following statements about polar bears are true or false? Read them, then write true (T) or false (F) or I don’t know (?) in the first column beside the statements. Compare and discuss your answers.

STATEMENTS	YOUR OPINION	THE EXPERT’S OPINION
Polar bears suffer from being in captivity.
In zoos polar bears walk up and down in their cages or rock their bodies from side to side.
In the wild, polar bears walk thousands of square kms.
Polar bears behave normally in zoos where they have hills and lakes to live in.
Polar bears are an endangered species.
Polar bears cannot be observed in the wild.

Listen to this interview with a wildlife expert to find out whether he thinks the statements are true or false. Write T or F in the second column. Then check your answers with a partner. Do you agree with what the expert says?

READING

With your partner try to match the definition with the correct word or phrase. Guess if you are not sure! Then scan the text quickly to see if you were right.

1. Biodiversity a A plant that only lasts a year

2. A species b An end to birth

3. Genetic resources c Many different forms of life

4. A perennial d A legal agreement between countries

5. An annual e A plant that grows every year

6. Extinction f A group of animals, plants or microorganisms sharing a common genetic structure

7. A treaty g The great variety of different species of animals, plants and microorganisms

8. A predator h Smb or smth that hunts

When we think of wildlife facing extinction, we are usually thinking of large majestic animals such as whales, elephants, rhinos or panda. These creatures are indeed at risk of extinction because of irresponsible and cruel hunting by human predators. But the threat of extinction is not limited to the few species that we can recognize in pictures or visit in zoos, it affects almost every species on earth.

A species is a group of animals, plants or microorganisms that share a common genetic structure. Members of a species can mate with one another but not with members of another species. The earth probably contains between 10 and 100 million different species, although scientists have so far only identified 1.4 million of them. There is a new word in English that underlines the importance of conserving the world’s genetic resources: biodiversity, which means biological diversity or, literally, “many different forms of life”.

The balance of nature within any ecosystem depends on the complex interaction between millions of species of animals, plants and microorganisms. The death of one species could threaten the survival of hundreds of others. A second species might lose its food supply and it, too, might become extinct. Another species could lose its predators, so it might become more numerous.

In general, organisms that live in the wild are stronger and more resistant to disease than domestic strains. They can replace domestic strains that develop disease. A recent example of the benefits of biodiversity is a species of wild corn discovered a few years ago growing in a Mexican forest. The wild corn was extremely hardy and was resistant to viruses that often attack cultivated corn. The wild strain was a perennial (that is, it grew again spontaneously every year), whereas other forms of corn are annuals (that is, the farmers must sow new seeds every year). Scientists successfully cross-bred the wild strain with domestic varieties and created a new, hardy, perennial strain of cultivated corn.

Today, scientists are trying to store wild animals of all the staple food crops in case the domestic strains develop disease. But we cannot always rely on scientists to restore the balance of nature when it goes wrong. The world’s ecosystem is far too complicated. The best place to store our genetic resources is in their natural habitat.

Conserving biodiversity was one of the most controversial subjects of the UNCED conference in Rio de Janeiro in 1992. The genetic resources in the rainforests, coastal waters, and agricultural landscapes promise financial profits in future years if we invest money in protecting biodiversity today. The conference produced the biodiversity treaty, but the richest country in the world, the USA, refused to sign it because they thought that the financial liability for their country would be excessive.

Extinction is final. It does not just mean death; it means an end to birth. Once the last member of a species has died, that species is lost to the planet forever. Man has the power to upset the balance of nature but he does not have the power to restore that balance. This is why we must try to protect every living species on the earth – even the ugliest insects and the tiny, invisible, unglamorous bacteria.

Дата добавления: 2014-11-16