Animal and Plant Domestication: Archaeological and Genetic Evidence

Introduction: Domestication and Human Development

One of the most difficult and interesting questions posed to researchers and students alike is the longitudinal development of humanity. Within this broader question lies one that is often called the basis or beginning of modern human development: the domestication of plants and animals. It is argued that when humans adopted the domesticated practices of agriculture and husbandry, they began to move forward in development, freed from the constant demands of hunting and gathering everything needed to survive (Smith 15). This work addresses that question by summarizing the anthropological approach to domestication, briefly comparing it to the genetic research model, and evaluating it as a process in the broader puzzle of developing a record of early humanity. The main focus is then to compare archaeological evidence as it applies to the animal record and the plant record.

Two Schools of Thought: Archaeological vs. Genetic Approaches

There are generally two schools of thought with regard to tracing the origins of domesticated agriculture and husbandry: the archaeological approach and the genetic approach. Both are used to give the body of research a more complete picture, yet they are sometimes at odds with one another, as they can and often do produce differing scientific theories and results. The genetic school studies domestication by examining changes in an organism's genetic profile that result from contact with humans (M.A. Zeder et al. 5). The archaeological school, by contrast, utilizes accumulated archaeological processes to identify locations and times associated with domestication events, often relying on new technology to build a case for linear and localized changes in ancient DNA, as well as changes in the morphologies of the flora or fauna being studied — frequently guided by previously established genetic findings (8). There is no doubt that the marriage of these two approaches will greatly increase the body of knowledge concerning the domestication of both flora and fauna.

The Plant Domestication Record

The archaeological record with regard to plant domestication includes a number of variable forms of evidence. These can be sought through examination of a chain of evidence in the record: a behavioral change occurs in the manner that people interact with the plant, a genetic change occurs in the plant itself, and a morphological change follows as the plant becomes physically distinct in the record. Utilizing this chain, the archaeologist can examine a wide array of evidence, seeking everything from geological changes wrought by human intervention — such as landscape alterations that indicate agricultural clearing, general disturbance of an area for the purpose of planting, and evidence of human efforts to obtain water for irrigation — to specific comparative changes within the plant itself, through comparison of wild species with suspected domesticates as they appear regionally, side by side in the record (Smith 16).

Archaeologists can also examine the morphological changes found in seed plants, grain caches, and seed grains that have been consumed and are now part of the waste products of domestic living (17). Seed stocks found in the archaeological record provide a significant clue to the nature and level of domestication, as the differences between wild plants and those selected as seed plants are significant and notable, with human intervention known to select for that change. Seeds with thinner hulls and larger bodies are selected in cultivation to generate faster results in planting (18). The result is a morphologically different seed grain in domesticates as opposed to wild plant seeds, and this differentiation can occur rather quickly in the process. It then becomes evident in seed caches intended for both planting and consumption, as well as in the refuse that is often the most valuable material of an archaeological dig (18).

Conclusion

This work offers a brief introduction to the relatively new integration of archaeology within the field of genetics, and vice versa. Both are tools that attempt to create a holistic picture of the domestication of plants and animals. This discussion establishes a starting point for understanding the archaeological record as it applies to plants and animals in comparison, and it is clear that both are disciplines requiring great skill and knowledge. The nature of the animal, with its complicated biology as compared to a plant, creates a demonstrable difference in the complexity of studying animal versus plant domestication through the combined lenses of archaeology and genetics.

Works Cited

Emshwiller, E. 2006. "Genetic Data and Plant Domestication." In Documenting Domestication: New Genetic and Archaeological Paradigms, edited by M.A. Zeder, D.G. Bradley, E. Emshwiller, and B.D. Smith, pp. 99–122. University of California Press, Berkeley.

Smith, Bruce D. 2006. "Documenting Domesticated Plants in the Archaeological Record." In Documenting Domestication: New Genetic and Archaeological Paradigms, edited by M.A. Zeder, D.G. Bradley, E. Emshwiller, and B.D. Smith, pp. 15–24. University of California Press, Berkeley.

Bradley, D.G. 2006. "Documenting Domestication: Reading Animal Genetic Texts." In Documenting Domestication: New Genetic and Archaeological Paradigms, edited by M.A. Zeder, D.G. Bradley, E. Emshwiller, and B.D. Smith, pp. 273–278. University of California Press, Berkeley.

Zeder, M.A. 2006. "Archaeological Approaches to Documenting Animal Domestication." In Documenting Domestication: New Genetic and Archaeological Paradigms, edited by M.A. Zeder, D.G. Bradley, E. Emshwiller, and B.D. Smith, pp. 171–180. University of California Press, Berkeley.