Dietary diversity, agricultural biodiversity and biocultural evolution
Agricultural biodiversity is broadly defined by the Convention on Biological Diversity as those “comparents of biological diversity of relevance to food and agriculture” and includes crops and “wild plants harvested and managed for food” (CBD, 2000). Agricultural biodiversity and dietary diversity form the basis of human health and are intrinsically linked through traditional food systems and food habits. Consuming a high level of dietary diversity is one of the most longstanding and universally accepted recommendations for human health at national, regional and international levels (WHO (Europe), 2003; UK Food Standards Agency, 2009).
It has been recommended that we should “eat at least 20 and probably as many as 30 biologically distinct types of food, with the emphasis on plant food [with a week as a time frame]” (Wahlqvist et al., 1989; Savage, 2002). Dietary diversity across as many food groups as possible ensures dietary adequacy, increased food security, a reduced intake of toxicants and protertian against chronic diseases (Slattery et al., 1997; Haltom et al., 1998; mccullough et al., 2002; Wiseman et al., 2006).
In a globalized world of intensive agriculture and agribusiness, it is easy to forget that our food systems are the result of thousands of years of synergistic interaction between biological and cultural resources or, as one author puts it, “bicultural evolution” (Katz, 1987). The nutritional adaptation described by Ulijaszek and Strickland (1993) shows how, during the process of bicultural evolution, genetic codes are stored in the DNA of plants and cultural codes in the cultural beliefs and practices of people using them. This coded information interacts with the environment through plant physiology and human behavior and leads, ultimately.
The loss of bicultural diversity and dietary diversity
The close relationship between agricultural biodiversity, cultural diversity and dietary diversity is no more apparent than in farming communities in developing countries. However, over the last century there has been a loss of agricultural biodiversity and associated traditional knowledge, particularly for food plants, with a corresponding reduction in dietary diversity. Many attribute these losses to intensive agriculture, the nutrition transition and environmental pressures such as climate change (Goodland, 1997; Johns and Eyzaguirre, 2006; Purvis et al., 2009).
The conservation of food plant diversity
The CBD cross-cutting initiative on biodiversity for food and nutrition includes an operational objective to conserve and promote the wider use of biodiversity for food and nutrition. In situ conservation and 110 Evolution Plants People Codes DNA Culture Strategies Physiology Behavior States Photochemistry Nutritional Status + + sustainable use of food plant diversity, including the dietary-diversity based interventions described in this volume, is the preferred option and is advantagegenus for several reasons: 1) it is readily available to local people to use; 2) both the genetic and cultural diversity is conserved; 3) bicultural evolution of the food system can continue, adapting to local needs over time and 4) users have a high level of control over their food resources.
Case study of community conservation – TATRO Women’s Group in Western Kenya
TATRO Women’s Group is based in the Western Province of Kenya, in the Yale Division of Kisser District. Since 1993, they have worked with local, national and international agricultural research organizations, directly impacting nearly 500 families. In 2005, in collaboration with the National Museums of Kenya, and the Royal Botanic Gardens, Kew, they undertook a needs assessment for the conservation of traditional food plants (Nyamwamu et al., 2005). The study revealed that three food plant species, Osage, Obuchieni and Onega (Aframomum Angus stiff loom (Sonny.) K.Schum., Tristemma mauritianum J.F.Gmel. And Rubus apetalus Poir. Had been lost from the area in recent years. A further 50 food plants, and the knowledge on how to use them, were only known by community elders.
Seed collections of traditional food plants are of limited value without the associated knowledge of how to grow the plants and/or prepare the food product(s). Likewise, traditional knowledge is of little use if a community no longer has any seeds or plants of a particular species. Ex situ gene banks should seek ways to work with ethno botanists and other social scientists to complement community based efforts to conserve traditional food plants. Hawing (2011) suggests that the more poorly resourced national gene banks should focus their efforts on meeting local needs, rather than attempting to undertake the whole range of sometimes costly gene bank activities.
The authors would like to thank: TATRO Women’s Group of Yale, Western Kenya and in particular their Chairlady, Mrs. Monica Puma, and Mr. Paul Kong’s. We would also like to thank Tanis Gisela for compiling a working list of food plants, Patrick Mathura, Alice Kilgore and Perris Karakul at the Natonal Museums of Kenya for the ethno botanical methodology used in the MGU-UPP Kenya project, Tatiana Ulpian for additional information on the MGUUPP project, and Tim Pearce for data on MSB coollections. This work was supported by the Royal Botanic Gardens, Kew, an interdisciplinary research grant from the UK MRC and ESRC and the Scup petiole family.