What primarily drove the explosion of diversity seen in coat color, size variation, and temperament in modern yak herds?
Answer
Focused, intense artificial selection applied by pastoralists.
While the fundamental physiological machinery allowing yaks to live at high altitudes (like superior oxygen uptake mechanisms) is a result of long-term natural selection acting via the harsh environment, the visible variation seen today in domestic populations is human-directed. Pastoralists actively selected for traits that maximized economic return and ease of management over thousands of years. This intense artificial selection favored changes in temperament (docility), size optimization for labor, and variations in coat quality and color suitable for textiles, leading to the wide array of modern herd characteristics distinct from the wild type.
Related Questions
What critical physiological trait allows yaks to scavenge oxygen efficiently in thin air?When was evidence suggesting the creation of a "super yak" through early selective breeding estimated to occur?How does the wild yak (*Bos mutus*) differ physically from its domesticated relative (*Bos grunniens*)?Relative to domestic cattle, what key anatomical feature characterizes the yak respiratory system for high-altitude survival?Beyond providing milk, meat, and fiber, what essential resource do yaks supply to pastoralists in treeless regions?Which species is commonly used as a reference point when identifying regions of the yak genome under strong positive selection?What primarily drove the explosion of diversity seen in coat color, size variation, and temperament in modern yak herds?What rough timeframe is cited for the genetic split between the wild yak lineage and the domestic yak lineage?What term is used to describe the hybrid offspring resulting from the interaction between domestic yaks and cattle?What traits were favored in early domestic yaks through artificial selection, contrasting with natural selection on wild yaks?