Introduction to Biodiversity
Introduced| English | Meaning |
|---|---|
| biodiversity/ˌbaɪəʊdaɪˈvɜːsɪti/ | The variety of life, including genetic diversity, species diversity and ecosystem diversity. |
| genetic diversity/dʒɪˈnetɪk daɪˈvɜːsɪti/ | The variety of genes *within* a species. |
| species richness/ˈspiːsiːz ˈrɪtʃnəs/ | The number of different species present in an area or community. |
| resilient/rɪˈsɪlɪənt/ | Able to recover or maintain important functions after a disturbance or change. |
The richness of life
- Life on Earth comes in a staggering variety.
- Millions of species, each with its own genes, fill countless habitats.
- This total variety of life is called biodiversity.
- It exists at three connected levels.
Three levels of biodiversity
- Biodiversity 生物多样性 is the variety of life at every scale.
- Genetic diversity 遗传多样性 is the variety of genes within a species.
- Species diversity is the variety of different species in an area.
- Ecosystem diversity is the variety of habitats and ecosystems across a region.
Biodiversity has three levels: genetic, species, and habitat
Biodiversity is…
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Biodiversity is the variety of life — genes, species, and ecosystems.
Measuring species diversity
- Species richness 物种丰富度 counts how many different species live in an area.
- A rainforest with thousands of species has high richness.
- Diversity also considers how even the species' numbers are.
- More even, more species usually means higher biodiversity.
Species richness means…
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Species richness simply counts how many different species live in an area.
The variety of genes within a single species is called ____ diversity.
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Genetic diversity is the variety of alleles within a species — the raw material for adapting.
Why it matters
- Higher biodiversity makes an ecosystem more stable and resilient 有韧性的.
- If one species is lost, others can fill its role.
- Diverse ecosystems supply food, medicine, and clean water.
- And genetic diversity gives species the raw material to adapt.
Which level of biodiversity?
Sort each example by the level of biodiversity it describes - genes, species, or whole ecosystems.
Lower biodiversity generally makes an ecosystem more stable and resilient.
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False. Higher biodiversity generally gives more stability: with more species and genetic variety, an ecosystem can better withstand disease, disturbance and change.
Select all true statements about biodiversity.
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Biodiversity is variety, so it is never just one species. The other three are correct.
Biodiversity is more than just counting species. Genetic diversity within a species matters too: a crop with little genetic variety can be wiped out by a single new disease, while a genetically diverse population can survive it. Look at all three levels, not just the species count.
Why genetic diversity saved a crop:
- In the 1970s a disease attacked the world's rice, and most varieties were vulnerable.
- Scientists found one wild rice with a rare resistance gene — an example of genetic diversity.
- Breeding that gene in saved the crop. Without that hidden variety, the harvest could have failed.
Biodiversity is the variety of life at three levels: genetic (genes within a species), species (species richness counts them), and ecosystem (variety of habitats). Higher biodiversity makes ecosystems more resilient and supplies food, medicine, and the genes species need to adapt.