Nothing exists in a vacuum, and nature relies on many key players to keep everything running smoothly.

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What is the most harmful type of diversity loss?

The flagship species that draw attention and funds to critical conservation zones also help protect biodiversity. But in the greater scheme of things, they aren't necessarily the species that need saving the most. Often more important are the diminutive insects, unmemorable plants and indiscernible microorganisms that are really the heavy hitters in terms of ecosystem health. Without them, the whole shebang would come crashing down around us.

None of this is to say that flagship species like whales, leopards and wolves don't serve a purpose. They do, and their purpose is often very important for their respective habitats. When wolves were reintroduced to Yellowstone National Park, they helped bring the elk population back into balance, which in turn aided trees, trout, birds, beavers and bears. It's just that when we consider the species that keep the planet running, there's the definite chance that if a certain flagship species were to go extinct, another species would eventually evolve to fill the relevant niche. In the case of small organisms or plants, however, we're talking about much more critical issues.

Consider the role of organisms like plants, algae and cyanobacteria in the ecosystem, both on land and in the sea. They photosynthesize carbon dioxide using water and energy from sunlight, to transform CO2 into chemical energy that biological organisms can use. Basically, they act like the planet's batteries -- holding streams of raw power until other living creatures consume them. Even carnivores rely heavily on the services of life forms they don't consume directly: The giraffe a lion takes down most certainly survived on plants before its untimely demise.

And what about bugs? Well, let's talk honeybees. Of the approximately 4,000 species of bees in North America, the Western honeybee (Apis mellifera) has unquestionably been the top dog in terms of industry for many years. Forget honey; forget wax. The honeybee is an economic powerhouse because it's a highly effective pollinator -- to the tune of about $15 billion a year in pollination services in just the United States alone. Honeybees aren't picky -- they'll pollinate practically anything, and with gusto [source: Scientific American].

Next, we'll look at why trouble with a tiny creature like the honeybee means trouble for everyone.

Colony Collapse Disorder

Western honeybees play a part in the creation of nearly every food product in the supermarket, from the cold cuts in the meat section all the way over to the fruits and vegetables in produce. Over the past few years, however, an issue known as colony collapse disorder has cropped up; now honeybee colonies are vanishing in droves. Scientists aren't exactly sure why it happens, only that it's a big problem in terms of food production unless a solution -- or a suitable replacement pollinator -- is found in a hurry.

Insects and other unassuming organisms serve similarly crucial functions for agriculture and industry, not to mention the fact that many species that wouldn't normally attract much notice have provided the basis for several complex new medicines. Think how much penicillin has changed the world. That came courtesy of a lowly fungus growing on a cantaloupe. What poisonous scorpion, elusive mushroom or delicate orchid is hiding out in some remote or threatened habitat waiting to do the same?

Apart from providing the basis for future miracle drugs, smaller species aerate the soil, creating channels for water to flow and reach thirsty plants; they decompose organic matter, returning valuable nutrients back into circulation; and they help balance their own population numbers by eating one another. Without the unimaginably vast and diverse army of insects, plants, microorganisms, and other easily overlooked species chugging away on the factory floor of our planet, it would be game over pretty quickly.

So what's the most harmful type of diversity loss? To put it another way, the real question might be this: Who's more important -- the big animals near the top of the food chain or all the little guys who populate the bottom? And phrased like that, the smaller and often less impressive species might just come out ahead. Dinosaurs ruled the turf for a time, and then they kicked the bucket. But life went on. Apex predators such as saber-toothed cats and dire wolves grew huge in their day, and you don't see them around anymore. But luckily, even if the planet suffers another mass extinction, as long as enough biodiversity remains among the underdogs, life should be able to pull through and continue into the future.

Lots More Information

Related HowStuffWorks ArticlesMore Great LinksSources
  • 2010 International Year of Biodiversity Web site. http://www.cbd.int/2010/welcome/
  • "Ask the Experts: DeeAnn Reeder on bat research" Bucknell University. Feb. 4, 2010. http://www.bucknell.edu/x58280.xml
  • "Are We Pushing Earth's Environmental Tipping Points?" Scientific American. March 19, 2010. http://www.scientificamerican.com/podcast/episode.cfm?id=are-we-pushing-the-earths-environme-10-03-19
  • "Bee Afraid, Bee Very Afraid." Scientific American. August 14, 2009. http://www.scientificamerican.com/podcast/episode.cfm?id=bee-afraid-bee-very-afraid-09-08-14
  • Carey, Bjorn. "The Perils of Being Huge: Why Large Creatures Go Extinct." Live Science. July 18, 2006. (8/25/2010) http://www.livescience.com/animals/060718_big_animals.html
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  • "Why Save Endangered Species?" U.S. Fish and Wildlife Service. July 2005. http://www.fws.gov/endangered/esa-library/pdf/Why_Save_Endangered_Species_Brochure.pdf
  • Whitty, Jennifer. "Animal Extinction - the greatest threat to mankind." The Independent. April 30, 2007. http://www.independent.co.uk/environment/animal-extinction--the-greatest-threat-to-mankind-397939.html
  • Wilson, Edward and Peter, Francis. "Biodiversity, Volume 1." National Academy of Sciences and the Smithsonian Institution. March 16, 1998. http://books.google.com/books?id=MkUrAAAAYAAJ&lpg=PA21&ots=AyXtCAQcps&dq=what's%20worse%20loss%20of%20plant%20diversity%20or%20loss%20of%20animal%20diversity%3F&lr&pg=PP1#v=onepage&q&f=false
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