Lecture 10 ANTH 170c1 Outline of Last Lecture I Horticulture II Social structure III Agriculture IV Bridewealth vs Dowry V India dowry female infanticide Outline of Current Lecture I Cell division II III IV V Menstruation cycles and cancer risk Menstrual cycling patterns in natural fertility societies Menstrual cycling patterns in modern contraceptive populations Increased risk of breast cancer in modern societies compared with non contraceptive societies Additional factors Male reproductive cancers Testosterone and competition VI VII VIII Current Lecture Title Cell Division I II III Cell division and cancer a Each time a cell divides all of the dna in the cell must be copies b Errors in dna replication can lead to cancer c The more cell divisions the higher the like hood of cancer Menstruation cycles and cancer risk a More cycles more cell division b Higher risk of cancer causing mutation Menstrual cycling patterns in natural fertility societies a No contraceptives b Average age of first menstruation 15 years c Average age at first birth 19 years d Average number of children 86 e Average cycle length of cycling women 28 5 days f Median number of menses per life time 109 year IV V VI VII Menstrual cycling patterns in modern contraceptive populations a Average age of first menstruation 12 years i Average age of first birth 25 years ii Average number of children 2 iii Average cycle length for cycling menses 28 days Increased risk of breast cancer in modern societies compared with non contraceptive societies a 12x higher risk in modern contraceptive societies Additional factors a Nutrition i Highly positive energy balance higher hormone levels more cell division Male reproductive cancers a Prostate cancer b In westernized societies all men who live long enough get prostate cancer c Correlated with exposure to testosterone d Males who are under more stress due to challenges from other males e Men with lower socioeconomic status have higher average levels of competition