Biodiversity, Extinction, and Conservation

What, why, and how

A Tigress' Oasis  by Dee Ann Pederson

A Tigress' Oasis by Dee Ann Pederson


What exactly is biodiversity? How are we losing it?

From user "Atheist Son" on

From user "Atheist Son" on

Biodiversity, or biological diversity, refers to the variety, abundance, composition, distribution, and interactions of all life on Earth, including millions of animal and plant species as well as fungi, single celled creatures called protists, and bacteria. Each species plays a part in maintaining the balance of nature. We can look at biodiversity up close at the genetic level, or from far back at the ecosystem level. Here, we’re focusing mostly on species diversity within ecosystems.

We don’t know how many species there are on earth. Many have yet to be discovered. Estimates are all over the place, with some even guessing up to a trillion species (including microbes and bacteria). But estimate that most scientists agree with is around 8.7 million species (not including microbes and bacteria) with about 80% of those undescribed.  

Because we don’t know exactly how many species there are, we don’t know how many go extinct each year. The Center for Biological Diversity suggests that a dozen or so species may be going extinct every day. But it’s hard to know what we’re losing when we don’t even know what we have.

Why are so many species going extinct? We can only thank ourselves and our apparently insatiable need for space and resources. Humans consume more of Earth’s natural resources relative to population size than any other animal, and as of 2002, only 17% of the world’s land surface was untouched by people.

Not much biodiversity to be found here...

At the moment, the greatest threat by far (at least for land animals) is loss of habitat due to agriculture and urban development. Optimizing an ecosystem to perform one function, like growing corn and nothing else, decimates biodiversity. Some of the most biodiverse parts of the planet – tropical rainforests, temperate forests, and freshwater ecosystems – are at the most risk from habitat destruction for human land use.

Bleached coral - the photosynthetic algae have died because of warmer and more acidic oceans

Anthropogenic (human-caused) climate change and rising global temperatures are also a major threat to biodiversity, especially in our estuaries, wetlands, and shallow oceans. Warmer water and higher acid levels kill tropical corals, algae, and plankton, which are the base of the marine food chain. The delicate balance of freshwater and salt in estuaries, which is crucial in the life cycle of many animals, is thrown off. Polar bears come farther and farther south as the arctic ice melts, and enter the native territory of brown bears.


Other human-caused threats to biodiversity include:

  • Poaching – the illegal and unregulated hunting of animals for profit from meat, hides, horns, ivory, or the pet trade
  • “Pest” eradication – killing wild animals that we decide aren’t welcome, like wolves or spiders
  • Feeding wild animals – when animals learn to like human food, they try to stay near people to get more food, can get sick easily, and sometimes must be killed for human safety
  • Introduction of invasive species – adding a new foreign species to an ecosystem, which can throw off an entire food chain, outcompete native species, or wipe out native animals that haven’t evolved to have a defense system
  • Dumping chemicals into waterways – using chemical fertilizers, pesticides, or herbicides, and then allowing them to be washed into nearby streams and rivers, where they poison fish, amphibians, plant life, and insects, and everything that eats those things
  • Littering or irresponsible waste disposal – tossing trash by the side of the road, not recycling plastics that could harm wildlife, or wasting food that was grown on giant farms

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Why is biodiversity loss such a big problem? Haven't species been going extinct forever?

Charles Darwin's famous sketch of his theory of evolution through natural selection

Charles Darwin's famous sketch of his theory of evolution through natural selection

With all the environmental problems we’re facing these days – rising sea levels, air and water pollution, acid rain, coral bleaching, oil spills, forest fires, polar ice melting, and deforestation, just to name a few – you may be wondering: why does biodiversity loss deserve special attention?

Extinction, or the death of every member of a species, is a normal event, and has been happening since the beginning of life on Earth about 4.3 million years ago. Species that cannot survive or adapt to their environment die out, and are replaced by ones that can. Natural selection is… well, natural.

What’s not natural is the rate of extinction we’ve seen in recent years. A normal, healthy rate of species extinction is the loss of one to five species in a year. But currently, extinction rates are 1,000-10,000 times higher than that. Some scientists predict that if current trends continue, we’ll see a new mass extinction event (at least 75% of species gone, which would be catastrophic) within the next 250 years. Others say that it’s already happening, and has been going on since human agriculture and civilization began about 12,000 years ago. It’s called the Holocene extinction, or sometimes the Anthropocene extinction.

Graphic by Dr. Thomas R. Holtz Jr., University of Maryland

Graphic by Dr. Thomas R. Holtz Jr., University of Maryland

There are a huge number of reasons why biodiversity is important, but they can be categorized into two major categories: ecosystem maintenance, and human well-being. We’ll come back to the human stuff later, but what exactly is ecosystem maintenance? All life relies on the tasks performed by healthy ecosystems, which include food production, climate regulation, pest and disease control, decomposition (breaking down dead organisms), and the creation of clean, breathable air. Each organism (living thing) in an ecosystem plays a role in at least one of these processes, and taking even just one away can have far-reaching and apparently disproportionate consequences.

Above: Wolves hunt an elk.               Below: A beaver builds a dam.

Photo by Marcin Klapczynski

One pretty well-known example of this is the wolves of Yellowstone National Park. Government predator control programs looking to protect farmers’ livestock herds eliminated the park’s last gray wolves in 1926. Without large predators, the elk population exploded and drove out other herbivores. After a decades-long campaign, wolves were re-introduced in the park in 1995. The wolves now control the elk herds, which has led to several chain reactions. Beavers can get food and resources now, and they build dams that create ponds, which form habitats for many other creatures like moose and frogs. The coyote population has also dropped now that they have to compete with wolves, which in turn has allowed the fox population to rise, and the foxes help keep the smaller herbivores in check. The simple re-addition of a single species was enough to restore dozens of others.


Now you may be thinking, “Fine, but how does biodiversity loss affect me?” Although humans appear to be thriving with a population approaching eight billion, we too are directly affected by biodiversity loss. We’re more removed from the natural world now than we’ve ever been, but we still need what it provides. As we’ve seen, the loss of species can have far-reaching and unprecedented effects on ecosystems, which in turn can affect the people and industries that depend on them. Those who directly depend on the environment for resources, like the rural poor, are especially effected. Biodiversity loss can also have huge effects on other human problems, including physical and mental health, politics, well-being of future generations, and even conflict or war.

Human activity undoubtedly affects nature, but we often don’t realize that nature affects us just as much in return. We must protect biodiversity for our own sake, if not for ecological and ethical reasons.

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Why aren't people paying more attention to this problem?

A red-spotted newt. Amphibians like newts, salamanders, frogs, toads, and caecilians (essentially legless salamanders) are more at-risk than any other class of animal, but they're not nearly as charismatic as lions or gorillas.

When’s the last time you saw heard a sensational report about a frog vanishing off the face of the earth? Or the headline in your local newspaper or online news source was about how difficult it is to find certain birds these days? The sad truth is that biodiversity and wildlife conservation stories rarely make it to the mainstream media, so many people are completely unaware of them.

The problem is that biodiversity loss is simply not as interesting to the public as other environmental issues. Global warming and sea level rise are new problems. Climate change is exciting. On the other hand, species have always disappeared, so why should we pay attention? Now it’s just a lot faster than usual. And because the media doesn’t present biodiversity loss as an urgent issue, lots of people don’t realize that there’s a problem at all.

Obviously some folks are aware of it though, and that number appears to be on the rise. We shouldn’t celebrate just yet though – there’s still a lot of misrepresentation of biodiversity in the media. People tend to think of the beautiful, exotic, faraway creatures that have been used to represent wildlife. How often do you see tigers and pandas and elephants in the media, compared to salamanders or mountain goats, or the bees that live in your neighborhood? Even we used a picture of a tiger at the top of this page. Of course, we're not trying to say that the pandas and tigers are less important than the other animals. But showing only those charismatic few can be dangerous, since it doesn’t present an accurate picture of what’s really at stake.

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What can I do in my everyday life to help protect biodiversity?

Photo by Eleifert

  • NEVER FEED OR HARASS WILDLIFE! (birdfeeders with sustainable birdseed are okay.)
  • Check food labels, and avoid foods that contain palm oil – palm oil is produced on farms that destroy southeast Asian jungles, home to orangutans and many other animals and plants.
  • Process waste responsibly – recycle, compost food waste, cut apart plastic soda rings, and don’t litter or waste food.
  • Avoid using harmful herbicides, pesticides, chemical fertilizers, and use eco-friendly soaps and cleaners.
  • Support sustainable businesses, including food producers and clothing manufacturers.
  • Don’t buy ivory, rhino horn, animal hides, or other animal products (like meat) that you don’t know where they came from or how they were obtained.
  • Reduce how much stuff you consume in general.
  • Walk, bike, or take the bus instead of driving. Help fight climate change!
  • If a “pest” animal is native to the area you're in (and you're not in immediate danger), leave it alone! It’s an important part of the ecosystem.
  • Keep your pets under control – domestic cats and dogs kill huge amounts of native animals.
  • Donate a little bit of money to any of these organizations.
  • Spread the word! Talk to your friends and family about biodiversity loss.
  • Share your photos with the world to show them how amazing the natural world is. 

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I have some extra time and resources. What else can I do to help?

Photo by Bob Peterson

  • Plant native plants in your garden instead of foreign ornamentals.
  • Grow bee friendly plants – check with a local botanic garden for suggestions.
  • Remove invasive plants that might be driving out the natives in your neighborhood or local park.
  • If you have invasive wildlife around that’s endangering native creatures, set traps for them, or contact local conservation organizations or animal services to figure out what to do.
  • Pick up litter and throw it away properly.
  • Call or write to your local politicians, and ask them to create or support polices that protect wildlife and wild places.
  • Visit a national park, national forest, or a wildlife refuge – or better yet, volunteer for them.
  • Volunteer for local conservation groups or other environmental organizations.
  • Help out with bird counts and other biodiversity crowdsourced research.
  • Educate kids – organize outdoor/wildlife themed activities for local schools and community groups.
  • Donate a bit more money to any of these organizations.
  • And it’s worth repeating – SERIOUSLY, DON’T FEED OR HARASS WILDLIFE!

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