Biodiversity in Agriculture
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Many years ago when interest in environmental science started one of our key texts was Ucko and Dimbleby’s “Domestication and Exploitation of Plants and Animals”. This was a set of conference proceedings whose basic tenet was to examine how we came to have our modern set of plants and animals. Only a small subset of ideas around then suggested that we might need to consider loss of agricultural varieties. Within about 20 years it became very plain that the agricultural heritage upon which we relied for so long was slowly being reduced (actually, quite quickly in some places!). We realised that in the drive for uniform production and some sort of aesthetic appeal, we were losing vital sub-species. This lead to a range of reactions from the creation of rare breeds sites (the Rare Breeds Survival Trust comes to mind) to a more cavalier approach to diversity loss especially in the EU where the number of varieties might decline by well over 90%. Alongside this, the academic interest seemed to be reduced. There were still studies but the texts on domestication (always a slim field) became almost non-existent. What makes this text so interesting is that it is one of the first to tackle not only the ecology of species creation but the implications of species decline – the argument that biodiversity, whether “natural” of human-made” is still worthy of conservation.
The text starts with an introduction that not only sets the scene but poses ten questions that, it suggests, remain unanswered even after all the research. Looking through them they are the most fundamental – where did agriculture originate? What local ecological conditions favoured it mover hunting and gathering? What are the species characteristics most favoured for domestication? It’s clear that in these ten questions we have the basis of understanding in this field. They’re the ones we started to ask as we began to study the development of agriculture and it’s the direction of this text as we go through the various sections. We start with a look at the very origins of agriculture. The section overview, takes up the picture by considering why anyone would want to start in the first place. What are the benefits of agriculture? Obviously it gives people a cost-effective and compact supply of food allowing a certain degree of settlement in an area but this then poses the question as to the nature and range of species that might be worthwhile in farming: the characteristics are limited which reduces the candidates from, for example, 4000 wild species to 14 domesticates. From this overview, a range of chapters tackle key issues. The first looks at the development of agro-ecosystems – the idea that more people depended on fewer and fewer species which demanded special conditions to thrive. The arguments developed here are demonstrated in four further chapters looking, in turn, at development in specific places and the evidence that supports these claims. Finally, two cases examine the evidence for agricultural development.
Section two examines the seemingly simple, but in reality complex, idea of domestication. Yes, we all know that cattle became domesticated but precisely how and why? It turns out that this child-like question has several answers. Far from their being one pathway there are several and the evidence for this comes increasingly from detailed genetic studies as the case study of the dog, shown here, demonstrates. A final, brief chapter highlights that domestication, by whichever pathway is not an evolution but a co-evolution because as animals started to evolve so did human ability to digest their milk. A further intriguing link is provided by the notion that the spread of cereals is linked to rickets but that milk is linked to its reduction (and that of malaria). If so, we realise that agriculture is a far less benign system than previously thought but one almost approaching symbiosis. The third section turns to plant domestication and the routes taken to develop it. Examples chosen cover both time and space. Domestication might have been the first part of agriculture but, as we see here, it is still going on today. “Ancient” examples of rice and lima beans show the centres of origin but also the spread of new varieties in response to new environments. Contemporary examples of cassava, yam and pigeonpea show how partially domesticated species can be improved and make the step to a new generation of foodstuffs. Given that these are in the less developed areas, such findings are important.
Section four marks a shift away from purely domestication to question the agricultural system as a whole. The basic tenet here is that as species become domesticated so do the organisational, political, social and ecological systems that underpin them. Simply, agriculture and its species are co-evolutionary. The importance of this is profound because, unlike “natural” conservation, agricultural conservation dictates we need to conserve the system within which it is found. One example stands out here. A chapter on indigenous peoples show how they maintain biodiversity and adapt to changes such as climate change. Despite a solid record in this, it’s noted that they are not considered when making climate mitigation schemes. The final section examines current and future directions for biodiversity and domestication. The range of examples given is impressive: the domestication of new fruit and nut trees in developing areas, extensions to the California wine industry, bees, yeast and aquaculture. It’s fitting to end with the idea that the potential that has started 10,000 years ago does not yet seem to have come to and end.
This is a fascinating text. It covers one of the most interesting cases in human development – the idea that we evolved alongside our food! It shows the select ways that successful species can be domesticated, it argues why there aren’t more and it hints of what could be done. Despite it’s technical detail(it’s aimed squarely at the undergraduate/graduate market) it contains a wealth of examples and ideas that could stimulate considerable discussion a range of education settings.
