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...
Also
on this date:
