HSCI 216 Chapter Notes - Chapter 7: Homo Sapiens, Concealed Ovulation, Fallopian Tube
6 May 2015
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100 eggs in lifetime vs. 2-4 million spermatozoids per ejaculate + continuous production. Egg survival 6-24 hours vs. 48 hours for spermatozoids. Timing pregnancies with religious beliefs, family and social mandates, or to facilitate the achievement of life goals (eg. academic and economic) Ancestral costs: maternal depletion, increased offspring mortality. Adaptationist paradigm: reproductive losses does not equal reproductive failures: suppression mechanisms regulate timing of reproductive events. Conditions are better for modern women so we can afford to have more children. Acidic lining of walls of vagina (to protect against bacterial infection) Just over half will make a copy of itself and divide into cluster of 8 identical cells; journeying along fallopian tube to uterus. Contractions of orgasm might help to draw sperm into uterus. Junction between vagina and uterus, cervix: dipped time and time again into a pool of waiting sperm. Parasitic relationship: before 9 weeks, raids mother"s blood for nutrients; invade mother"s uterus.
