The term “biological diversity” was first used in 1968 by wildlife scientist and conservationist Raymond F. Dasmann in is book A Different Kind of Country advocating conservation. However, the term was only widely adopted after more than a decade, coming into common usage in science and environmental policy in the 1980s. It was Thomas Lovejoy who, in the foreword to the book Conservation Biology, introduced the term to the scientific community.

Since then, the term has been used among biologists, environmentalists, political leaders and concerned citizens. The 1992 UN Conference on Environment and Development (Earth Summit) defined biological diversity 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, between species and of ecosystems”. This definition is used in the UN Convention on Biological Diversity – the international document defining biodiversity-related policy at global level.

The objectives of this convention are “the conservation of biological diversity, the sustainable use of its components and the fair and equitable sharing of the benefits arising out of the utilization of genetic resources, including by appropriate access to genetic resources and by appropriate transfer of relevant technologies, taking into account all rights over thos resources and to technologies, and by appropriate funding”.

Agricultural biodiversity is part of the biodiversity on land and can be divided into two catecories:

  • Intraspecific – the genetic variety within a single species.
  • Interspecific – the number and types of different species that are cultivated, like potatoes, carrots, peppers, lettuce, etc.

Interspecific crop diversity is, in part, responsible for our food diversity while intraspecific diversity within a single species offers us choices in our diet and adaptability to local climatic conditions. If a crop fails in a monoculture, we rely on agricultural diversity to provide something new to be replanted; if a pest destroys a wheat crop, a more resistant wheat variety may be planted the following year. Biodiversity can also provide solutions in cases of agricultural disasters:

  • When rice grassy stunt virus (RGSV) struck the fields from Indonesia to India in the 1970s, 6,273 varieties were tested for resistance. Only one Indian variety was found to be resistant, only known to science since 1966. This variety hybridized with other varieties and this hibryds are now widely known.
  • The coffee rust disease attacked coffee plantations in Sri Lanka, Brazil and Central America in 1970. A resistant variety was found in Ethiopia.

Monoculture practice has been a contributing factor to several agricultural disasters, including the European wine industry collapse in the late 19th century and the US Southern corn leaf blight (SCLB) epidemic of 1970. The Irish potato blight of 1846 caused the death of one million people and the emigration of around two million more. It was the result of planting only two potato varieties, both vulnerable to the disease Phytophthora infestance, which arrived in 1845.

Although about 80 percent of humans’ food supply comes from just 20 plant varieties, humans use at least 40,000 species. Many people depend on these species for food, shelter and clothing. Earth’s surviving biodiversity provides resources for increasing the range of food and other products suitable for human use, although the present extinction rate is shrinking that potential.

Therefore, twenty years after Rio Earth Summit, the United Nations designated the period of 2011-2020 as the UN Decade on Biodiversity.