In some mammals, including hedgehogs and porcupines, the hairs are modified into difficult spines or quills. These are covered with thick plates of keratin and function protection in opposition to predators. Jablonski[55] asserts head hair was evolutionarily useful for pre-people to keep because it protected the scalp as they walked https://fernandodkpvu.qodsblog.com/36059221/indicators-on-hair-salon-in-ottawa-you-should-know