BIO 1300 Lecture Notes - Lecture 3: Homo Ergaster, Seasonal Affective Disorder, Offal
Document Summary
Topic 3: skin, nakedness, colour and the ozone layer. Humans are the only primates to have lost entire coat of body fur. Important evolutionary stage in humans: also have different skin pigmentations due to adaptation to particular climates. Important sensory role: mechanical touch and pain receptors which plays an important role in senses: some keratinized extensions in certain animals are highly innervated and can be used as sensors ex: whiskers on dogs and cats. Inbreeding avoidance: inbreeding can cause the expression of negative traits ex: hemophilia. Fingerprints and wrinkles as an adaptation to wetness. The naked ape: refers to the fact that humans are the only member of the primate family that have lost almost all body hair. The mammal hair: hair is a uniquely mammalian trait, many important functions, protection, abraision, sunlight. Parasites: camouflage, due to different levels and types of pigmentation, species recognition, social communication, example: sexual mate choice. Insulation: most likely the first function of hair.
