From: Gabija ® 24/01/2002 10:24:08 Subject: Why do I have hair? post id: 589109 I am not sure whether this has been asked before but I have been wondering why do I have hair on my head, underarms and below my tummy. I remember my grandma telling me that the hair keeps my head warm. Do my underarms then need to be worm!? Is it just a left over from our grandgrandgrand.....parents? If so, why in these areas only? From: michael c (Avatar) 24/01/2002 11:29:20 Subject: re: Why do I have hair? post id: 589190 My suspicion is that a lot of the various patterns of body hair on humans is a result of sexual selection. From: Gabija ® 24/01/2002 11:41:04 Subject: re: Why do I have hair? post id: 589215 I wonder when the fashion of shaving/waxing came in? And why do we like hair only on our heads. :-) From: michael c (Avatar) 24/01/2002 11:41:30 Subject: re: Why do I have hair? post id: 589216 The hair I was thinking of was more like chest and facial. Certainly in other species sexual dimorphism is a result of sexual selection. Waxing could only be considered a very recent modification in terms of human evolution. From: Lysander 24/01/2002 12:16:25 Subject: re: Why do I have hair? post id: 589315 People have hair on their head to protect them from overhead sun. People have hair around their eyes & genitals to attract the attention of the opposite sex. The two-piece swimsuits that girls wear at the beach highlight their attractions even more effectively than hair. And they use eye-shadow to augment their eyebrows & eye-lashes, demonstrating again what hair's purpose is. A beautiful girl with hairy underarms is actually a turn-on. Only this Anglo-Saxon culture is perverse enough to suppress it. European women are proud of their body hair & underarm hair. In much of Asia a girl with hairy legs is regarded as especially sexy. And, to boot, the fragrance of a healthy girl's armpits is divine. Only unhealthy people stink like billygoats. From: Zardoz ® 24/01/2002 12:25:04 Subject: re: Why do I have hair? post id: 589339 Hair on the head probably serves a dual purpose: preventing heat loss when it's cold (body heat is lost rapidly through the head, which is why mothers caution us to wear a hat in winter) and protecting the scalp from ultraviolet radiation and the sunburn and skin cancer it can cause (bald people are especially prone to skin cancer on the scalp). Pubic and axillary (armpit) hair are examples of secondary sexual characteristics: external structures (other than genitals) that can be used to distinguish the sexes. Other secondary sexual characteristics include facial hair in males, breast development in females and body structure in both sexes (wider hips in females, broader shoulders in men, etc.) These traits appear at the same time as reproductive maturity and are often under control of the same hormones. In fact, the word "puberty" comes from the Latin root "pubes," which means hair. Today, the amount, appearance and pattern of pubic hair are one of the criteria by which physicians determine what stage of pubertal deveolpment an adolescent is in. For our ancestors, pubic and axillary hair were probably one of several visual signals that an indivdual was fully mature, and therefore could be considered as a potential mate by a member of the opposite sex. The different patterns of pubic, facial and body hair in humans (along with other secondary sexual characteristics) result in sexual dimorphisms in mature humans: males look different than females. Among our primate relatives, strong sexual dimorphisms most often occur in polygamous species. In monogamous species, such as marmosets, males and females look much more alike. It is hypothesized that our early human ancestors had a polygamous mating system in which males competed for females. As for why the hair that signals maturity appears specifically on the pubic and armpit regions, we can only speculate. Males of many species rely on odor cues (called pheremones) as signals that a female is fertile, or in the stage of her estrus cycle where conception is most likely to occur. Indeed, for many animals, this is the only phase in which a female will mate. Humans, however, mate during all phases of the menstrual cycle, and for the most part do not seem to rely on odor signals. However, there is some evidence that humans may retain a limited capacity to respond to pheremones. Women housed together (as in a college dorm) tend to have synchronized menstrual cycles. In one experiement, secretions from a woman's armpits were collected and applied to the upper lips of other women, who subsequently began to have synchronous cycles, suggesting that odor is the cause. Men are also reported to prefer the smell of human vaginal secretions from women in the fertile part of their menstrual cycle to over those from other times of the cycle. Perhaps these types of odors were more important to the reproductive success of our ancestors who lived before the days of regular bathing and deodorants. If so, having hair in these regions may have helped the odors to stay around longer and be more easily detected by potential mates. http://www.madsci.org/posts/archives/mar97/853738132.Ev.r.html From: J.F. ® 27/01/2002 22:08:09 Subject: re: Why do I have hair? post id: 595201 I wonder when the fashion of shaving/waxing came in? I think the priests of ancient Egypt removed all hair from their bodies, as part of purification. The practice may go back even further, who knows? It's only become possible recently. I think they plucked out the hairs. This forum is un-moderated. The views and opinions expressed are those of the individual poster and not the ABC. The ABC reserves the right to remove offensive or inappropriate messages.