Download Biodiversity can simply be defined as the variation of life at a given

Importance of Biodiversity
Biodiversity can simply be defined as the variation of life at a given
site or ecosystem. However, it is through this diversity that natural
systems adapt, evolve, and thrive. “This link is so strong that the term
biodiversity is regarded as synonymous with ecosystem health.”1
Diverse ecosystems usually have “increased stability, increased
productivity, and resistance to invasion and other disturbances.”2 It is
these features that make biodiversity desirable within a given
biological community/biome. Most importantly, biodiversity holds
enormous value for the entire planet!
1.Look at the italicized quote. Explain
this quote in your own words.
Biodiversity is considered to exist at three levels: genetics, species,
and ecosystems.
2.Compare and contrast the three
levels of biodiversity and explain how
they are similar and how they are
different.
Genetic diversity: the total number of genetic characteristics in the
genetic makeup of a species.3 Genetic diversity allows species to adapt
to changing environments. This diversity aims to ensure that some
species survive drastic changes and thus carry on desirable genes. The
survival of individuals ensures the survival of the population.
Species diversity: a ratio of one species’ population over total number
of organisms across all species in the given biome. ‘Zero’ would be
infinite diversity, and ‘one’ represents only one species present.
Ecosystem diversity: the diversity of a place at the level of
ecosystems.4 The Earth is our ‘biosphere,’ and the variation of
ecosystems within our biosphere is a measure of ecosystem diversity.
Biodiversity is measured by two major components: species richness,
and species evenness.5 Species richness if similar to species diversity,
but it simply measures the total number of species in an ecosystem.
The second component is species evenness, which gauges the
proportion of species at a given site, e.g. “low evenness indicates that
a few species dominate the site.”6
Many of us are aware of a natural balance that occurs within nature
where some species benefit from others and in turn fuel a vibrant
ecosystem. This phenomenon is so powerful that an entire philosophy
has arisen from its premise. The “Gaia” philosophy believes that
living organisms on a planet will “affect the nature of their
environment in order to make the environment more suitable for
life.”13 Biodiversity is critical for this to occur since only evolutionarily
advantageous traits will remain and continue to support life on Earth.
The pattern of life supporting life is so strong that some take the Gaia
philosophy to an extreme and hold that the Earth itself is a living, selfregulating, coevolving, organism.14 We view the intricate parts of this
vast organism daily, but they work together and evolve together in
such a way that they resemble a single entity. There is clearly a
“spectrum of Gaia hypotheses, ranging from the undeniable to
radical,” but the significance of biodiversity remains.15 Biodiversity
promotes a balanced ecosystem, which is one in which living species
co-exist for mutual benefit.16
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3. Think about your local biome.
Explain how your biome measures up
in species richness and species
evenness.
4. Ocean algae emit sulfur into the
atmosphere. This sulfur provides
water vapor the needs surface to form
raindrops and create rain. Explain how
this is an example of the “Gaia
Philosophy”.
A specific location that has enormous species diversity but is also
under threat from human activities is known as a biodiversity hot
spot.7 According to Norman Myers, two key criteria must be met for an
area to be considered a biodiversity hotspot: “it must contain at least
1,500 species of [plants known to only exist in that region (endemic)],
and it has to have lost at least 70% of its primary vegetation.”8 At
least 25 areas around the world meet these qualifications, and they
“support nearly 60% of the world's plant, bird, mammal, reptile, and
amphibian species.”9 This gives you a sense of how many unique
species are under threat from human impacts around the world.
5. Using context clues from text, define
the term “endemic”.
Biodiversity has continued to fall in recent years, and this is due in
most part to: “habitat loss and degradation, climate change, excessive
nutrient load and pollution, and invasive species
.”24 Of further
concern is species extinction
. Humans have had an undeniable
effect upon the extinction of species. In the 20th century, the
extinction rate of species worldwide was 1000 times larger than the
average rate during preceding 65 million years; this may climb to
10,000 times the background rate during the next century.25 Perhaps
even more shocking is a look at what overharvesting can do to a
population. 90 percent of big ocean fish have been harvested in the
last half century because of industrial fishing practices starting in the
1950s.26
7. Use statistics from the text to explain
how we know that humans are to
blame for the species extinction
worldwide.
With the shifting climate and increased ecosystem stress, many
scientists warn of mass extinctions in our lifetime. The largest study
of its kind claims that “15 to 37 percent of living species” will be
extinct by mid-century, this is equivalent to 1.25 million species.27 The
study says climate change
is to blame. Climate change will force
species to migrate to new regions and adapt or die as a result. To put
it bluntly, “up to 70% of the world’s known species risk extinction if
the global temperatures rise by more than 3.5°C.”28 The largest
biomes under direct threat are polar ice
and ocean coral reefs
Natural variation is responsible for the vibrant and complex natural
environment that we call Earth. Without biodiversity, a single plague
or extreme weather event could wipe out entire populations within a
biome. Shifting climate patterns can place equivalent stress on
species. With increased biodiversity, comes an increased likelihood
that a portion of the species will survive, adapt, and repopulate.
However, with mass extinctions caused by habitat destruction,
pollution, invasive species, and climate change, natural variation is
threatened. Biodiversity is yet another reason why human society
needs to reassess how me meet our housing, farming, and industry
needs, or risk the irreversible destruction of millions of species—the
full impact of which we may never know. The good news is that there
are conservation efforts underway, and there is hope for species
conservation and reintroduction,
we just have to start making it
a top priority on a global scale.
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6. Various rainforests around the world
are considered “biodiversity hotspots”.
Explain why logging in these areas
qualify these biomes as hotspots.
8. Would you consider species
extinction due to climate change a
human cause? Explain your answer.
9. Think back to your game play.
According to the last paragraph, why
was it easier to maintain the
populations or organisms in the biomes
with more biodiversity.
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