title: Golden Spirals and Scalp Whorls: Nature's Own Design for Rapid Expansion.
abstract: This paper documents what began as an exercise in curiosity-logarithmic spiral designs abound in nature-in galaxies, flowers, even pinecones, and on human scalps as whorls. Why are humans the only primates to have whorls on the scalp? Is the formation of scalp whorls mechanical or genetic? A mechanical theory has long been postulated- the mechanical theory suggests that hair whorl patterning is determined by the tension on the epidermis during rapid expansion of the cranium while the hair follicle is growing downwards-however, this has never before, to the author's knowledge, been experimentally proven conclusively. We found, that under certain conditions, we were able to experimentally recreate spirals on the scalp to demonstrate that the basis of scalp whorls is indeed mechanical-and that logarithmic spirals may be nature's own design for rapid expansion of organic tissues. Given our experiments only created whorls when certain conditions were satisfied (and not in others), they have given us great insight into the mechanical formation of skin whorls and the physiology of skin stretch. We believe that these findings will lead to many more advances in understanding skin dynamics and indeed the changes that occur in tissue when confronted by stretch.
authors: School of Medicine, University of Queensland, 288 Herston Road Herston QLD 4006. Australia.|Faculty of Surgery, University of Auckland, 2 Park Road, Grafton, Auckland 1023, New Zealand.|Auckland University of Technology, 55 Wellesley St E, Auckland 1010, New Zealand.
authors: Sharad P
authors: http://orcid.org/0000-0001-9601-9109
authors: SP
authors: Paul
mesh_terms: D000818:Animals; D012535:Scalp; D033081:Shear Strength; D012867:Skin / Q000033:anatomy & histology* / Q000254:growth & development*; D013552:Swine