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Glossary
Biotechnology: any technological application
that uses biological systems, living organisms, or derivatives thereof, to make or
modify agricultural or industrial products or processes
Conservation: sound management of biological resources, ensuring their long-term
viability
Ex situ conservation: conservation of elements of biological diversity
outside their natural habitat
In situ conservation: conservation of ecosystems and natural habitats,
maintenance and reconstitution of viable populations of species in their natural
habitat, and, in the case of domesticated and cultivated species, in the habitat
where their distinctive characters developed
Ecosystem: a dynamic complex of plant, animal and micro-organism communities
and their non-living environment interacting as a functional unit
Species: a group of organisms which are naturally capable of interbreeding because
of their genetic and physical resemblance
Endemic species: species present within a localized area (e.g. an ecosystem,
island, or country)
Protection: prohibition or reduction of human activities in natural areas in order
to maintain biodiversity
Taxonomy: the study, designation and classification of living forms
Transgenic: used to describe a living organism into which genetic material
has been introduced from another species in order to cause new characteristics to
appear
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Plants seem to have been sown
with profusion over the Earth like the stars in the sky to invite man by way of pleasure
and curiosity to the study of nature.
Jean-Jacques
Rousseau,
French writer and philosopher (1712-1778)
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Paradoxically, scientists
know more about the stars in our galaxy than about the number of species living on
Earth
 Coined by American researchers
in the mid-1980s, the term biodiversity has been in the media spotlight ever since.
It is a highly complex concept which is still not widely understood by the general
public. For scientists, the area of research it covers remains uncharted territory.
According to the Convention on Biological Diversity adopted in Rio de Janeiro (Brazil)
in 1992, biodiversity is defined as “the variability among living organisms from
all sources including, inter alia, terrestrial, marine and other aquatic ecosystems
and the ecological complexes of which they are part; this includes diversity within
species and of ecosystems.”
In plain English, biodiversity is both an idea and a physical reality. As an idea,
it refers to the “variability” of living organisms, namely to their ability to evolve
in space and time, to adapt and to survive. But it is also a physical reality, comprising
all living organisms and the relationships between them. The concept of biodiversity
can be broken down into three different levels: genes, species* and ecosystems*.
Surprising as it may seem, scientists know more about the number of stars in our
galaxy than they do about the number of species living on Earth. Taxonomists* have
inventoried approximately
1.7 million living organisms–plants, animals and micro-organisms (bacteria, viruses,
fungi, etc.).
But a host of others exist in nature and it’s anybody’s guess exactly how many. The
most common estimates vary between eight and 15 million, but some range up to 100
million. It would appear that the environments with the highest number of endemic*
species are humid tropical forests.
2,000
apple varieties identified worldwide
With the exception
of mammals, the higher plants and birds, scientists are rather unfamiliar with species–and
so they are light years away from understanding everything there is to know about
genetic diversity. On the one hand, each individual in the same species possesses
a multitude of genes that are responsible for its own characteristics. Humans have
approximately 100,000, and researchers have not yet identified them all. On the other
hand, genetic diversity is expressed through the existence of distinct populations
within the same species. For example, some 2,000 varieties of apple have been identified
worldwide. For thousands of years, humans have taken advantage of genetic diversity
to domesticate wild species, particularly through cross-breeding. Today, biotechnology*
allows scientists to go faster and further by creating new varieties of transgenic*
plants and animals.
In nature, species are not isolated but live in relationship with larger ecological
complexes, which make up, with their physical environment, the planet’s ecosystems.
Here again, scientists acknowledge that they know very little about how ecosystems
work (see
pp. 26-27)
and the role they play in the diversity of living organisms.
* These terms are defined
in the
glossary.
Biodiversity in
Questions, a series of colour wallcharts for teachers and students, published by
UNESCO/MAB in 1998.
Global Biodiversity Assessment, UNEP/Cambridge University Press, 1995.
www.wri.org
www.iucn.org
www.conservation.org
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The Earth’s 25
“hotspots”
What can be done to ensure that every dollar
invested in the conservation of biodiversity pays off? The selection of 25 “hotspots”,
the most ecologically rich places on the planet, is one step towards answering that
question.
A team of researchers led by British scientist Norman Myers (Oxford University) and
the NGO Conservation International made the selection. They hope that their choice
will lead to a worldwide conservation campaign focused on the 25 sanctuaries. Most
of the sites are in the tropics. Five of them are in the Mediterranean region. Their
conservation will probably cost $500 million a year.
Taken together, the sites cover an area as large as Greenland (1.4 per cent of the
Earth’s surface) and may harbour 44 per cent of the Earth’s plant and 35 per cent
of its vertebrate species. They do not include areas rich in endemic species that
are not yet under threat from humans. For example, the forest in French Guyana has
a population density of under five inhabitants per km2, but according to a recent
report by the NGO Population Action International, the population density in the
25 “hotspots” is twice as high as the world average.
Although this approach may be effective, it is not universally accepted by the scientific
community. Critics argue that too little is known about the geographical distribution
and richness of biodiversity to identify priority areas. They say the 25 hotspots
are too focused on tropical forests and neglect deserts, meadows, tundra and temperate
forests, as well as the wealth of marine biodiversity.
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