Manipulating Biology: Costs, Benefits and Controversies

Introductions

Manipulating Biology

Mankind has been manipulating the biology of living organisms for over 15,000 years when nomadic tribes began to use wild wolves to guard their encampments. They were able to do so because some of the wolves were less ferocious and able to be “trained” to perform tasks necessary for the tribe’s survival: thus, began the domestication of dogs. The domestication of wild plants began later, around 11,000 years ago, when hunter-gatherers noticed that certain species of wild grains had characteristics that made them easier to gather and plant.  One of these wild organisms was wheat which has two naturally occurring species: the dehiscent and the indehiscent variety.  Dehiscent wheat has ears that shatter upon maturity and the spikelets (containing the seeds) scatter onto the ground; the indehiscent species has spikelets that remain attached to the mature ears: thus, the spikelets (and seeds) can be easily gathered and stored.¹ As a result, early farmers would (whenever possible) choose the indehiscent wheat over its dehiscent counterpart. Their preference for one particular species was a form of artificial selection as it gave one variety of wheat an evolutionary advantage over all others. Over time indehiscent wheat became dominant as it was able to more successfully pass its genetic structure onto succeeding generations. In this manner humanity “domesticated” the wild grain as our actions ultimately determined the genetic structure of the wheat we use today. Domestication can be defined “as the genetically determined physical and physiological changes a plant undergoes in response to human behavior”.² In a similar fashion, Neolithic farmers discovered advantageous traits in 8 species of wild plants (emmer and einkorn wheat, barley, lentils, pea, chickpea, bitter vetch, and flax) that they successfully domesticated. The suite of organisms would become the “founder crops” of the early farms that populated the Fertile Crescent .³ Along with this domestication of wild plants, early farmers also began to select animals from wild herds (cattle, sheep, goats, pigs, and horses) that became valuable sources of food, energy, and clothing on early farms. As in the case of plants, they selected organisms with traits that would facilitate their domestication. Animals were selected based on “pre-adaptive” characteristics such as high meat yield, non-aggressiveness, tamable, and feeding habits, that eased their transition into the farm’s economy.⁴ Once again our preference for particular species determined the genetic structure of the many farm animals we have today.  As the farms and their surrounding settlements grew in complexity, humans continued domesticating an increasing number of wild organisms and animals that provided resources for the burgeoning populations. Their increasing ability to grow vast quantities of food, harness the power of animals, and invent an array of technologies laid the foundations of the economic, cultural, and sociocultural institutions that define the modern world.⁵

…viewing history in the light of evolution we see that it was intelligently designed changes to the genetic composition of natural biota that made the real [difference]. In some sense, Neolithic farmers were the first geneticists and domestic agriculture was the lever with which they moved the world.⁶