Wool is a natural textile fiber derived primarily from the protective coat of domesticated sheep. This material is prized globally for its warmth, durability, and ability to insulate. The story of this fiber spans millennia, revealing the profound impact of human selection on animal biology and the surprising range of species that contribute to the world’s wool supply.
The Deep History of Wool and Sheep Domestication
The journey of wool begins with the coarse, hairy coat of the wild mouflon, the ancestor of modern domestic sheep. Domestication first occurred in the Fertile Crescent approximately 10,000 to 8,000 years before the Common Era. Early shepherds valued these animals mainly for their meat, milk, and hides, as their coats were double-layered, consisting of a hairy outer layer and a fine undercoat.
The transformation into a continuously growing, soft fleece required thousands of years of human intervention. Around 6000 BCE, people began selectively breeding sheep that retained their undercoat, preventing the natural shedding process. This selection eventually resulted in a coat composed almost entirely of soft, crimped under-fibers, which could be spun into continuous yarn. This “woolly” trait is linked to a recessive allele that fundamentally altered the fiber growth pattern.
This breakthrough allowed early civilizations to move beyond using only animal hides for clothing. The newly developed woolly sheep quickly spread across Western Asia. By 3000 BCE, records in Mesopotamia indicate selective breeding focused on obtaining white-fleeced sheep for easier dyeing. From the Middle East, wool technology disseminated through trade routes, reaching the Mediterranean and Europe, where it became a foundational commodity for subsequent empires.
The Diverse Family of Wool-Producing Animals
While sheep are the primary source, the term “wool” applies broadly to fine, insulating fibers harvested from several other mammals. These alternative sources have unique characteristics and geographic origins, often entering the luxury fiber market due to their rarity.
Goats
Two distinct types of fiber are harvested from goats: cashmere and mohair. Cashmere is the fine, downy undercoat found on several goat breeds, notably the Capra Hircus, which thrives in the high-altitude regions of the Himalayas, Mongolia, and Kashmir. This coat is soft and insulating, developed to protect the animals from extreme winter temperatures. The fiber must be separated from the coarser outer guard hairs, a laborious process that contributes to its high value.
Mohair is the long, lustrous fiber harvested from the Angora goat, which originated in the Angora region of Turkey, now known as Ankara. Mohair fibers are coarser than cashmere but are known for their resilience and high sheen. This fiber often grows in long, wavy ringlets and is shorn from the animal twice a year, providing a durable material used in both clothing and furnishings.
Camelids
The Andean highlands of South America are home to two wool-producing camelids: the alpaca and the vicuña. The alpaca is a domesticated species, primarily raised in Peru and Bolivia, whose fleece is prized for its high thermal quality and wide range of natural earth-tone colors. Alpacas are separated into two main types: the Huacaya, which has a crimped, dense coat, and the Suri, which grows long, silky locks.
The vicuña, a smaller, wild relative of the alpaca, produces the finest and most expensive natural animal fiber in the world. This wool, which historically was reserved for Inca royalty, is soft and warm. Because the wild vicuña can only be safely shorn every three years, its fiber remains a rare and highly regulated commodity.
Rabbits
Angora wool is derived from the fur of the Angora rabbit, a distinct source from the Angora goat’s mohair, despite the similar name. The rabbit breed originated in the region of Ankara, Turkey, and was introduced to Europe during the 18th century. This wool is characterized by its softness, thin diameter, and a “halo” effect, which refers to the fluffiness created by the fine fibers.
How Specific Breeds Transformed the Fiber
The most significant transformation in wool quality came from selective breeding, with the Merino sheep serving as a prime example. The Merino breed was established in the Iberian Peninsula, developing a monopoly in Spain during the Middle Ages. The Spanish government valued the unique quality of this fine wool so highly that its export was strictly forbidden for centuries.
The Merino’s success stems from its fleece, which is characterized by a high density of hair follicles and a fine fiber diameter. This fiber also possesses a high degree of crimp, or natural wave, which traps air and provides insulation and elasticity when spun into yarn. Breeders intentionally maximized the Merino’s genetic propensity for continuous wool growth, resulting in an animal that requires regular shearing.
The global spread of the Merino, particularly its introduction to Australia and New Zealand in the late 18th century, fundamentally changed the wool industry. Australian breeders refined the fleece through intense selection, cementing its status as the global standard for fine wool. This focus created a clear distinction from coarser wools, which have a larger micron count and less crimp, making them more suitable for durable goods like carpets and industrial felts.