May 22, 2012 - International Day for Biological Diversity

What is “biological diversity”? And why should we care about it?

Well, it means the rich variety of animals, plants, and other living things. We humans have described about 1.4 million species of living things. That sounds like a lot, doesn't it? But there are probably many, many more kinds of species that we haven't yet discovered or identified. Experts guess that there might be ten million species altogether...

But that's just a guess.

How could there be so many different critters? Well, in one study, 19 trees in Panama were “fogged” with insecticide, and of course dead insects fell like rain. The insects were carefully collected and studied, and it turned out that there were nearly 1,200 species of beetles alone! Also, 80% of those beetles had been unknown to science before that time. Heck, many of the beetles live their whole lives on just one tree—and that particular species is unknown anywhere else, even on the next tree over!

More than a thousand beetles in 19 trees in Panama! And that's aside from all the other insects, spiders, and other arthropods; all the birds, mammals, amphibians, reptiles, mollusks, and other animals. And all the flowers, ferns, mosses, and other plants; all the mushrooms and other fungi; and all the amoebas and bacteria! And all the other trees in the rainforest, and all the other ecosystems on Earth!

(Pant, pant!)

Obviously, not all environments are as rich in biodiversity as a rainforest, and just as obviously, we don't want to wholesale kill everything on the planet just so we can count species! But that Panama study hints that we don't know nearly all of the creatures that we share the Earth with.

Okay, why is biological diversity important?

When we accidentally destroy habitats (by, say, introducing a kind of grass we humans like to walk and play on—but then that grass takes over and native plants die out) or when we purposefully eliminate habitats (by, for example, clearing forest so we can plant crops), we reduce biodiversity. I'm sure you've heard that many creatures such as the African elephant and the giant panda are endangered—but of course there are many much-smaller creatures, less-glamorous plants, and other important but little-known organisms that become endangered or even extinct when habitats are changed or destroyed.

Unfortunately, when we lose a few organisms, we often lose many more—because animals and plants and other living things are linked together in food webs and other kinds of interdependence. That's sad for the creatures, themselves, but it's also sad for humans: When we lose organisms, we may lose food sources. We often lose beauty. We may change the weather in unpredictable and usually uncomfortable ways. We lose potential sources of new medicines and cures.

We lose a lot.

Explore some more...

Check out the video on the Explore Biodiversity website. Then find out what you can do to help preserve biological diversity.

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