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Unformatted text preview: tication of many of those species. Comparisons of domesticated wild species with never-domesticated close relatives illustrate the subtle factors that can derail domestication1 (Fig. 1). For example, it is initially surprising that oak trees, the most important wild food plant in many parts of Eurasia and North America, were never domesticated. Like wild almonds, acorns of most individual wild oaks contain bitter poisons, with occasional non-poisonous mutant trees preferred by human foragers. However, the non-poisonous condition is controlled by a single dominant gene in almonds but polygenically in oaks, so that offspring of the occasional non-poisonous individuals are often non-poisonous in almonds but rarely so in oaks, preventing selection of edible oak varieties to this day. A second example is provided by the European horse breeders who settled in South Africa in the 1600s and — like African herders for previous millennia — tried to domesticate zebras. They gave up after several centuries for two reasons. First, zebras are incurably vicious, have the bad habit of biting a handler and not letting go until the handler is dead, and thereby injure mo...
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This note was uploaded on 12/10/2012 for the course HORT 306 taught by Professor Staff during the Fall '08 term at Purdue University-West Lafayette.
- Fall '08