Spinning Plant and Animal Fibers
By Brooklyn Museum - Spindle without Whorl, whole or Spindle with Cotton Yarn, Fragment. Brooklyn Museum. Retrieved on 2019-11-04.Attribution 3.0 Unported (CC BY 3.0) license, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=83653957
The beginning of twisting fibers from plants or animal coats is difficult to date because they don't fossilize, so we have to rely on trace evidence, such as imprints in mud that did fossilize. We have these of string-like skirts from the Upper Paleolithic that date to about 20,000 years ago. Recent discoveries, though, show that Neanderthals spun cording as well.
Photo of Neanderthal cord from Abri du Maras. M-H. Moncel
The evidence from the Neanderthals was actual fibers that were preserved in a cave in southern France. The fragment was 6mm long and was three bundles of twisted tree fibers twisted together. The most likely usage of the fiber was to be wrapped around a handle of some type or as part of a net bag. This implies many areas of knowledge held by Neanderthals to make the cording including the growth patterns of the trees the fibers came from, spinning, and spinning the resultant thread into a stronger yarn. 'In order to get this fiber, you have to strop the outer bark off a tree to scrape off the innter bark. This is best done in the spring or early summer,' according to Bruce Hardy, co-author of the study of these fibers and professor of anthropology at Kenyon College in Gambler, Ohio.
This spinning was most likely done against the thigh, twisting the fibers as the hand rolls it down the thigh, pinching them, and then bringing them back to the top of the thigh to be twisted more. The product was likely wound around a stick or stone.
By Rama - Own work, CC BY-SA 2.0 fr, https://commons.wikimedia.org/w/index.php?curid=49227927
The next step was to spin onto the stick, or spindle, directly, then to create a split or hook in the top of the stick to hold the twisted part on the stick. Exactly when this happened, we don't know, as there are, as yet, no direct remains of this process. What we do have evidence of improved technology is small bone and later metal hooks that replaced the slit or hook cut into wood as well as weights made of stone, wood, metal, clay, or later metal that went on the end of the sticks to keep them spinning longer called spinning whorl. These have been found as early as the Neolithic. The combination of these technological improvements is called the drop spindle and we have artwork depicting spinning from many cultures.
By © Marie-Lan Nguyen / Wikimedia Commons, Public Domain, https://commons.wikimedia.org/w/index.php?curid=2596494
The other item needed to make spinning easier is an item called a distaff, which would hold a prepared bundle of fibers is loosely wrapped onto, which freed the hand that would have previously held the fiber and allowed a larger quantity of fiber to be held at one time. The distaff could be tucked under the arm or into a loop or holder in a belt. Again, since this didn't fossilize, we don't know when it was developed, though it does appear in Bronze Age artwork.
If you're interested in learning to spin, local independent yarn stores are a good place to start. Other places to look are reenactment guilds, fiber craft guilds, or online for spinning classes. The benefit of guilds is in-person help learning and the benefit of companionship and experience.