Biological Diversity on
the Planet
How many different types of
organisms are on Earth?
Biological Diversity
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Refers to all of the different types of
organisms on earth
Organisms can live on land
(terrestrial), in water (aquatic) or
underground (subterranean)
What is a species?
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Group of organisms with the same
structures and can reproduce with
each other
Scientists estimate there are
between 30 and 100 million different
species living today
However, scientists have only
described just over 1.7 million
different species
Insects, Centipedes and Millipedes
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963 000 different
species (55.8% of
the world’s total
number of species)
Includes
mosquitoes,
beetles, flies, ants,
etc.
Plants
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270 000 different
species (15.6% of
the world’s total
number of species)
Includes all plants,
trees, ferns,
flowers, etc.
Fungi and Lichens
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100 000 different
species (5.79% of
the world’s total
number of species)
Includes
mushrooms,
lichens (fungi and
algae combined)
and others
Protozoans and Algae
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80 000 different
species (4.63% of
the world’s total
number of species)
Includes amoeba,
paramecium,
euglena and all
types of algae
Spiders and Scorpions
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75 000 different
species (4.35% of
the world’s total
number of species)
Includes all
spiders, tarantulas,
and scorpions
Mollusks
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70 000 different
species (4.06% of
the world’s total
number of species)
Snails, slugs,
clams, oysters,
mussels, scallops,
squid, octopi etc.
Crustaceans
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40 000 different
species (2.32% of
the world’s total
number of species)
Includes shrimp,
lobsters, crabs,
etc.
Roundworms
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25 000 different
species (1.45% of
the world’s total
number of species)
Common intestinal
parasite of pets,
hookworm,
pinworm and
trichinella
Fish
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22 000 different
species (1.27% of
the world’s total
number of species)
Includes all fish
such as salmon,
trout, bass,
marlins, sharks,
stingrays, etc.
Flatworms
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20 000 different
species (1.16% of
the world’s total
number of species)
Group including
flatworms called
platyhelminthes
Earthworms and Leeches
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12 000 different
species (0.70% of
the world’s total
number of species)
Just as the group
says, includes
earthworms and
leeches
Reptiles and Amphibians
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10 500 different
species (0.61% of
the world’s total
number of species)
Includes frogs,
toads, crocodiles,
iguanas, alligators,
etc.
Jellyfish, Corals and Anemones
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10 000 different
species (0.58% of
the world’s total
number of species)
Includes the above
species – jellyfish,
corals and
anemones
Sponges
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10 000 different
species (0.58% of
the world’s total
number of species)
Group including
the sponges is
called Porifera
Birds
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10 000 different
species (0.58% of
the world’s total
number of species)
Includes eagles,
hawks,
albatrosses, robins,
sparrows, etc.
Mammals
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4 500 different
species (0.26% of
the world’s total
number of species)
Includes bears,
monkeys, whales,
tigers, etc.
Bacteria
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4 000 different
species (0.23% of
the world’s total
number of species)
Found everywhere,
cause many
diseases and
illnesses in other
organisms
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Number of Species
90
Biological Diversity on Earth
80
1200000
1000000
800000
600000
400000
200000
0
1st Qtr
East
West
North
0
2nd Qtr
Group of Organisms
3rd Qtr
4th Qtr
Biological Diversity on Earth
Insect s
Plant s
Fungi and Lichens
Prot ozoans and Algae
Spiders and Scorpions
Mollusks
Crust aceans
Roundworms
Fish
Flat worms
Eart hworms and Leeches
Rept iles and Amphibians
Jellyf ish, Corals and Anemones
Sponges
Birds
Mammals
Bact eria
Species Distribution
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There are many more species located near
the equator (particularly in the
rainforests)
As you move further north or further
south from the equator, the number of
species decline – see example below
• Species of snakes in Mexico – 293
• Species of snakes in US – 126
• Species of snakes in Canada - 22