Genetic Diversity in Use

Source: Food and Agriculture Organization of the United Nations, 2013, Cary Fowler, Charlotte Lusty and Maria Vinje Dodson, and Global Crop Diversity Trust, "The Youth Guide to Biodiversity" 1st Edition (Chapter 3) Youth and United Nations Global Alliance. Reproduced with permission.

Chapter 3. Verbatim.

Diversity plays a key role in evolution and the survival of species. There are endless examples, from the dinosaur to the dodo, where a species lacked variation or the ability to adapt to pressures in its environment and became extinct. In the case of humans, we have so successfully adapted to our environment that we are now one of the major factors shaping and changing the planet. Despite this fact, we are still highly dependent on diversity at all levels.

Firstly, at an ecosystem level, diversity provides our habitats and environments. At the most fundamental level, plants provide the oxygen in the atmosphere. Our diverse habitats provide soils, water,homes, cover from the sun or wind, and many other services to support life.

Secondly, species diversity is important because humans eat an omnivorous diet and live in diverse environments around the world. Unlike cows and pandas, if we always eat the same, single type of food, we become sick because of a lack of essential nutrients in our diet. Diversity in our food systems is important to keep us alive. Diversity has enabled humans to colonise and thrive in many diverse living conditions around the world. Diversity also provides our medicines, timber, paper, fuel, raw products for manufacturing and just about everything else upon which human civilisation is based. 

Genetic diversity and the variation of traits that it provides allow individual species to adapt to changes in the environment. All species, such as humans, are under the constant threat of a new flu or other disease, as well as weather and temperature changes. Food may turn up reliably in supermarkets and shops but behind the scenes scientists and farmers are working constantly to keep up yields to meet the demand. Genetic diversity is the basis on which crops adapt and evolve in the face of challenges. 

Over the past 12 000 years, farmers have selected individual plants that yield more, taste better, or survive well under pressure. In different places or times, thousands of farmers used the seed from their preferred plants to sow the next season’s crop. In this way people have shaped crops to meet their needs under specific conditions. Thousands of crop varieties have been developed around the world. Modern-day breeders similarly select plants with specific traits, using various techniques or tools to speed up the process and to produce the high-yielding varieties that we are likely to buy in supermarkets. The box “The Making of Our Daily Bread” illustrates the importance of genetic diversity to wheat farmers.