Reading. 3.Read the text and find out what “biodiversity” means

3. Read the text and find out what “biodiversity” means.

Biodiversity

Biodiversity is a word that describes the variety of living things. “Bio” (from a Greek word) refers to living and “ diversity” refers to differences and variety. Living things express their diversity in hundreds of different ways – both external and visible and internal and invisible.

There are 3 kinds of biodiversity.

- Variety of genes

Poodles, beagles and rottweilers are all dogs – but they’re not the same because their genes are different. It’s the difference in our genes that makes us all different.

- Variety among species

Scientists group living things into distinct kind of species. For example, dogs, dragonflies, and daisies are all different species.

- Variety of ecosystems

Coral reefs, wetlands, and tropical rainforests are all ecosystems. Each one is different, with its own unique species living in it. Genes, species, and ecosystems working together make up our planet’s biodiversity.

There is genetic diversity within a species, which results in the differences between you and your brothers and sisters and cousins and grandparents even though we all members of the human race – the species Homo Sapiens. Genetic diversity is the reason why Siamese cats have different body shape and hair colouring from the black and white moggy net door.

There is evolutionary diversity, which has given rise to all the different species of animals and plants on this Earth and is genetic diversity on a wider scale. This is also known as species diversity.

Each species is adapted – and sometimes highly specialized – to survive in a particular environment or a range of environments. Only the human species, through cultural and racial diversity and technology, seems to have adapted itself to survive in almost every environment on the Earth.

Many of the world’s different plants and animals are under severe threat of extinction. Many species have already been lost. A species is said to be extinct when it has not been seen for over 50 years. Dinosaurs became extinct 65 million years ago but, in the last 50 years, more animals and plants have become extinct, because of hunting and loss of habitat. Globally, many hundreds of species will face extinction in a very few years without intensive conservation, education and environmental management and policy – making.

Much of the Earth’s great biodiversity is rapidly disappearing, even before we know what is missing. Species of plants, animals, fungi, and microscopic organisms such as bacteria are being lost at such alarming rates that biologists estimate that tree species go extinct every hour. Scientists around the world are cataloging and studying global biodiversity in hope that they might better understand it or at least slow the rate of loss.

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