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How human activities affect
nature
· Through thousands of years humans have developed to become less like their
hunter- gatherer ancestors and have become more self-reliant in some ways. Only in
recent years has:
· Human population risen dramatically
­ http://www.optimumpopulation.org/opt.earth.html
· Earth's resources being used more than it ever has before
· Other species have been harmed by our activities, even becoming endangered, and
then extinct
­ Species endangered include the African elephant, Tigers and the Polar Bear.
­ Species extinct by human activities include the Dodo
· There has also been a loss of biodiversity…read more

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Extinction
· The records of extinction show a current rate of 100-1000 times the normal
`background' rate of extinction, and with the large increase of population of humans,
there is growing speculation that us humans are the main cause of extinction of
species.
· In the more recent times human society has increased dramatically, there have been
784 recorded extinctions since the year 1500
· It is thought that 20% of species alive today could be extinct by 2030, and by the year
2100, up to 50% of species could be extinct.
· Although extinction is a natural process by evolution, the rates are high enough to
show that it is indeed humans, who speed up this process at a faster rate.…read more

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Loss of Biodiversity
A decrease in the number of species leads to a loss of
biodiversity. This occurs in many ways;
· Loss of Natural Vegetation
­ Humans clear large areas of natural vegetation to provide food for the growing
population. Unfortunately these areas are the habitats for a wide range of diverse
species, and taking away these habitats lead to extinction in the species.
· Replaced by Monoculture
­ A monoculture is a habitat which has a very low diversity, so there is small
chance of species populating in that area. A monoculture contains a single type
of crop only, which makes harvesting easier.
­ Palm oil, an essential product in human society, is taken from the oil palm. These
oil plant plantations are responsible for 87% of deforestation in Malaysia, with a
further 6 million hectares being scheduled for plantations in the future. Indonesia
has a further 16.5 million hectares are also scheduled to be cleared for the same
reason.
http://i.treehugger.com/…read more

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Human Activities
· The reasons behind the loss of biodiversity and cause extinction include:
­ Over-harvesting
· Hunting for food, such as over-fishing which brings many fish species to the brink of
extinction
­ Killing competitors for food
· These competitors include insects and fungi, which we kill by using pesticides
­ Pollution
· "Many toxic substances that are released inadvertently or in the process of waste disposal
are very similar to pesticides."
­ http://library.thinkquest.org/25014/why/indirect.pollution.html
­ Habitat destruction
· This is the build up of monoculture areas and break down of natural vegetation, as well as
deforestation, as mentioned in the previous slide
­ Inadvertent introduction of new predators and competitors to natural flora and
fauna
· New species more often than not devastate the other species in the area they are bought to.
The species can easily become involved in the food chain, becoming a new predator or prey,
bring new pathogens or parasites which may kill many species, or even destroy the natural
habitat.
­ With ref: http://en.wikipedia.org/wiki/Extinction#Predation.2C_competition.2C_and_disease
­ Killing for Protection
· Insects that are vectors for disease such as the female mosquito bringing malaria, or simply
removing a predator if it is deemed as a threat to the humans in the area.…read more

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Why humans need to conserve
species
· Biomimcry- using nature as design. Many designs
have been based upon ideas in nature, and are
important as an economical and ecological aspect.
­ Gecko tape is covered in nanoscopic hairs that
mimic those found on the feet of a gecko. These
hairs provide a van der Waals effect, which overall
provides a powerful adhesive tape.
­ Turbine blades have been developed to improve
efficiency in wind and hydroelectric turbines, which
have been based on the flippers of humpback
whales. Using such blades to catch the wind as
communities and nations switch to renewable
sources could provide a 20% increase in efficiency
that will help to make wind power generation fully
competitive with other alternatives.
­ Reference: http://brainz.org/15-coolest-cases-biomimicry/…read more

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