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In the late 1950s, geneticists began to analyze individual genes in plants, fruit flies and mice. Instead of finding genetic homogeneity or uniformity within such specialized species, scientists discovered that genes controlling specific proteins existed in many different forms. This phenomenon is called "genetic polymorphism" and we now recognize such variability is characteristic of vibrant, vigourous species. But diversity is actually important on many levels.
Over the 3.8 billion years that life has existed on Earth, there have been enormous changes - the Sun has increased intensity by 30 per cent; the atmosphere has changed from CO2-rich to high oxygen content; mountains and oceans arose and disappeared; warm periods have punctuated ice ages - yet all the while, life has flourished. The key to that persistence has been diversity at the gene, species and ecosystem levels within the biosphere. As conditions change, the "pool" of variability provides more options for adaptation to the new environment. We've learned from experience in agriculture, forestry and fisheries, that monoculture (the widespread growth of a single species or genetic strain) creates vulnerability to new diseases, pests or environmental conditions.
Human beings have evolved another level of diversity - culture - which has enabled us to flourish in diverse surroundings like the arctic, deserts, mountains and tropical forests. Unfortunately, globalization and the advancement of a single world economic model has created conditions that discourage diversity and encourage homogeneity in order to create favourable economies of scale. In other words, a Walmart is a Walmart is a Walmart. This has the effect of homogenizing the local cultures and diversity that may otherwise help provide resilience as conditions around us change. And this is why it is vital to encourage diversity within and between human societies - to maintain different world views and ways of thinking.
When the Iron Curtain fell, for example, we learned that Soviet secrecy and isolation resulted in different approaches to problems. As we reported on The Nature of Things, one technique involved surgical alterations of the cornea that has since been adapted as laser eye surgery. The Soviets also developed an immense boat-plane that skims just above water surfaces and is based on very different principles of lift and drag from conventional aircraft. And Soviet scientists exploited viruses that infect and kill specific bacteria as a way to fight disease. These developments are a reflection of original approaches and applications.
I recently visited Cuba, a nation that has been deliberately blocked from the global economy by the U.S., and saw enough to know they have much to teach us. The Soviet collapse suddenly deprived Cuba of their main market for sugar and source of cheap oil. Pesticides, fertilizers and big farm machinery became prohibitively expensive. It was a catastrophic economic crisis which necessitated new solutions. Today, four fifths of Cuban agriculture is organic and they are working towards 100 per cent. Vacant lots, lawns and yards now grow food so today, 80 per cent of leafy (non-grain) vegetables are grown and consumed within cities and towns.
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I visited an urban garden of three hectares in Havana which was started by four people in 1999 and now supports 76 paid workers who all live nearby. They grow worms to provide fertilizer for the soil, insects and bacteria to control pests, and plant species to attract pests or support insects that will prey on pests. Human muscles are the primary source of energy to tend the crops, yet yields per hectare are as high as industrial scale agriculture. Local people buy the produce (which is fresher, varied and free of chemicals), dozens of people are fully employed, the environment is cleaner and people develop a deeper appreciation of their relationship with food. By criteria of literacy, medical care, infant mortality, extreme poverty and homelessness, the United Nations rates Cuba as a developed nation. This, from a country that is in many ways cut off from the outside world.
As human population swells and our climate changes in the 21st century, we will encounter the limits of the resources our planet is capable of supplying. If we are to feed humanity and provide a high quality of life for our people we should try to protect diversity at every level now, because we are going to need all the help we can get.