Environment Quiz - Species Extinction (Answers)
Did you know that 99% of all species that ever lived are now extinct? Extinction is a natural process and usually around five species a year die out. However, we are currently undergoing a "mass extinction event". That's when 75% or more species die out over a short space of time. Hundreds, if not thousands, of species are dying out EVERY DAY. The reason for this? It's humans, of course. The damage we are doing to the environment is destroying our fellow Earthlings.
So, what exactly are we doing that is killing so many plants and animals? Quite a bit, is the answer. We are polluting our air, rivers and oceans; we're chopping down forests and draining swamps to make way for farms; we're hunting fish and other animals to the brink of extinction, and our cities are sprawling, removing the natural habitats of so many species.
So, what can be done to protect those species which haven't died out yet? As always, it's governments that can make the most difference. But we can all take action - even if it is just writing to our MPs to let them know how we feel.
If you enjoy questions on science, then you might want to try our KS3 Science section. 50 quizzes covering a large variety of topics learned at this stage in school.
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Few people believed in extinction until it was proven by scientist Georges Cuvier, 150 years after the dodo died out
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There are many different threats to wildlife but, for the time being, habitat loss is the greatest. Climate change is expected to become the biggest threat unless action is taken soon
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Mexico is the country with most species under threat. Indonesia come second and Madagasca third
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Invasive species cause problems for local wildlife, such as:
A lack of natural predators means their population can grow quickly Native species might be unable to defend themselves against the newcomers Native species may struggle to compete for resources |
Species such as elephants, tigers and rhinos (along with hundreds of others) are threatened by poaching
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Habitat destruction is caused by many human activities:
Mining for fossil fuels and minerals Deforestation River dredging Urbanisation Filling in swamps and wetlands Building river dams These are just a few. Even something as apparently innocent as mowing fields destroys natural habitats |
The number of fish in our oceans has shrunk dramatically. Some predict that by 2048 there will be so few fish left that they will be virtually extinct
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The reason we have earned this unwelcome moniker is that we kill apex predators (like sharks or tigers), as well as animals we eat. We also have a negative effect on food webs we should have no part in, due to pollution, habitat loss and the like. Humans do seem to be bad news for every other species we share the planet with
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These are just a few of the ways we can help. Others include growing native plants, reducing our water consumption, not buying plastics, reducing our carbon footprints, boycotting polluting industries, and lobbying our MPs
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444 million years ago, 86% of species were lost
375 million years ago, 75% of species were lost
251 million years ago, 96% of species were lost
200 million years ago, 80% of species were lost
And (most famously) 66 million years ago, 76% of species (including the dinosaurs) were lost
The current age is called the "Holocene extinction"