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How many species are there?
In these pages we'll learn:
- Total number of species recorded.
- Estimated species in the world
- Different Definitions of Biodiversity
- Biodiversity Links
Species estimates:
How many species are there in the world?
This is a very good question, but the truth is, its very hard to know, or even estimate. Currently there are about 1.4 million species described. Yet, we're probably far from being close to the actual number of species.
Take this into consideration. In a famous study conducted in Panama, 19 trees were "fogged" with insecticide and the dead were collected as they fell through the canopy. In this study, nearly 1,200 species of beetles alone were collected. Of those, 80 percent were not known to science. While it may be dangerous to extrapolate numbers like these to other places, it gives at least a high estimate of the number of species that could exist on earth - that high estimate being around 100 million species. A low estimate is 2 million. The best estimate might be around 10 million. But even if that’s the case, it means we've only known about a small fraction of what is presently there.
Many of the species that we're discovering live in areas that are
not often studied. Take the sea floor for instance. Hydrothermal
vents along the floor provide a type of chemical energy for bacteria.
These bacteria use this energy like plants use the energy of the
sun. They then form the base of a giant food web thousands of feet
below the surface. Only until recently have we been able to discover
this new habitat. Now scientists believe there could be as many
as a million species just in on the ocean floor.
Links:
70 percent of the world's species are in 12 countries:
Australia, Brazil, China, Columbia, Ecuador, India, Indonesia, Madagascar, Mexico, Peru, and Zaire.
Text by Rob Nelson
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