1. Mammalian Reproduction I Reproductive Strategies Reproductive Anatomy & Physiology Vaughan: 334-344, 354-359, 450-455 EEOB 625 4 February 2004

2. Mammalian Reproduction Evolutionary Considerations Why study reproduction? Evolution, Ecology, Physiology, and Animal and Human Health Life history strategies: a suite of adaptations providing a solution to major problems of existence (3 major ones) Body size, nutritional strategies, and length of gestation - Exceptions to the positive correlation of gestation length with adult body size related to diet

3. Mammalian Reproduction Evolutionary Considerations (cont.) Basic Modes of Reproduction & number of eggs: Oviparity, Ovoviviparity (egg retention) & Viviparity The" mammalian solution”: Polyestry and relatively short generation intervals related to high metabolic rates Trade-offs on litter size and the number of litters per lifetime Seasonal breeding: Proximal cues and the ultimate selective factor

4. Questions in Mammalian Reproduction I Why study reproduction? What is the advantage of sexual reproduction? Why is monogamy rare & polygyny common in mammals ? Why do most female gray squirrels come into estrus in early February and July? Female reproductive tracts: Are opossums and humans as different as they can be? Why the scrotum in male mammals ?

5. Fig 9.1, Feldhamer

6. Fig 9.1c, Feldhamer

7. Fig. 2, Harder & Jackson (1999) Sperm pairing in the epididymis of didelphid marsupials

8. Testis & Scrotum of a ram and a bore

10. Fig. 9.4, Feldhamer

13. Questions in Mammalian Reproduction II Estrous cycle and menstrual cycle: Is the difference in the name? Are the physiological, morphological, or behavioral changes different in the two types? Induced vs. Spontaneous ovulation: What is same and what is different about LH?

14. A.Estrous cycle: a sequence of physiological, morphological, and behavioral changes punctuated by recurring periods of estrus and ovulation B.Follicular and Luteal Phases punctuated by estrus and ovulation C.Control of estrus and ovulation: Estrogen, LH, and Progesterone D.Induced estrus and induced ovulation: Estrous Cycle, Estrus & Ovulation

16. Turner & Bagnara, 1976

17. Fig.9.6, Feldhamer