Anth 204 April 13, 2010.docx

ANTH 204 April 13, 2010 Decrease in Height Due to agriculture people stopped growing tall Smaller but less healthy Why Farm? Feeds people, more people require less land If we don?t people will die Who decides who should die and who shouldn?t? Competition leads to war Metal Ages Bronze age- After the Neolithic- metal working of Bronze. In Asia before 3000 BC, copper tin and ore Iron age- Iron ore or steel (1300 BC in Asia) Weapons, Tools and Ornaments Chapter 5- Biology in Living Humans Human Variation Understood in life history The details of an organisms existence from conception through sequence to death Homeostasis of the body is essential for our life cycle Growth and Development Growth (body size) Development (progression from immaturity to maturity) Growth Cycle Prenatal- conception to birth Postnatal- birth to 20 Adult- 20 and up Senescence- post child-bearing years Prenatal Exposure to smoking, alcohol, and drugs consumption and inadequate nutrition Major risks to the Fetus Birth- transition to life outside the womb is stressful- ½ of neonatal deaths occurs in the first 24 hours. Majority of these being due to low birth weight Postnatal 0-6 years, deciduous teeth come and go being replaced by permanent teeth, weaned on solid foods. Brain is fully grown Requires foods high in fats, protein and energy Post 6 require less nutritious foods but is essential prior to this point. Adolescence- approx. age 10-20 years Sexual maturation Girls- development of breasts and menarche Men- deepening of voice and facial hair Sexual defining or dimorphic features Coincides with a growth spurt of about 3-5 inches Completion of growth occurs with epiphyseal fusion once fused growth in length adding to an individual?s height is stopped Secular Growth Trend Secular trend- Periods of slowed growth and decrease in height due to periods of poor environmental conditions multi-factorial condition. Not such an issue in a single individual but in a population overall shows the unhealthy conditions for optimal growth and growth potential. More common in boys than girls possible due to physiological requirements?; Adulthood Aging- getting older Senescence- the body ability to maintain a stable internal environment (organs and physiological systems) when faced with environmental stressors This process of senescence is highly variable. Senescence In females- menopause- loss of ovarian function by 50 years of age In males- sperm and their motility into their 70?s even 70?s for some Bone loss post 40 is a huge problem- osteoporosis- can lead to broken bones (hip) and fractures (vertebral column) Human life History Sociocultural behaviors and our life history Live long compared to other primates (wild) and other hominids Humans have a prolonged childhood, infancy and lactation are short allowing for more birth and invest resources among all her children Food invested for all of these mouth, fat protein and energy- find food or support for offspring thorough her body- by lactation normally by the age of three. Grand mothering Hypothesis Humans are the only primate that have prolonged postmenopausal survival. Why? Play an important role for child rearing, provisional food and knowledge Human Adaptations Genetic- via natural selection (sickle cell anemia) Developmental- larger chest sizes at high elevations Acclimatization (physiological)- anytime in a persons life (darkened pigmentation) Cultural (behavioral)- insulted clothes in cold countries Functional Adaptations Functional adaptations within ones life time Associated with extreme environmental conditions All adaptations have a single purpose- maintain internal homeostatisis Climate, nutritional, workload, excessive activity Climate- Heat stress and Thermoregulation We are Homeothermic- maintain a caonstant body temperature 98.6 F. Over 104-107 F leads to organ failure and death In hot temperatures the body moves blood to the surface of the skin to get it away from the core (ref-faced) Equatorial places- Africa and South America Sweating- less effective in areas with dense hair-related to the general loss in humans of our body hair (these are two unique factors unique to humans) Humans can acclimatize to heat in 10-14 days Easier for men than women due to body fat All humans have thee same number of sweat glands and hair follicles Cultural adaptations- spicy food Less clothes Water Shelter Climate- body shape and adaptation to heat stress Bergman and Allen rules Hot climates- small narrow bodies and long limbs Cold Climates- Large wide bodies and short limbs Cold stress and thermoregulation Arctic and Antarctic at Earths poles, high altitudes above 10,000 ft (3 km) Hypothermia- low body temperature leads to loss of proper functions and eventually death Heat conservation (blood constriction) and heat production Cultural adaptations- clothing and shelter buildings and making Acclimatisation- After a few days- overall adjustment being able to tolerate cold temperatures produce more heat shiver less and higher skin temps Measured by Basal metabolic rate Inuit and Peruvians in the Andean mountains (higher metabolic rates) Diet- animal protein and fat low in carbs