title: The evolution of viviparity.
mesh_terms: D000220:Adaptation, Biological; D000663:Amphibians / Q000196:embryology; D000818:Animals; D005075:Biological Evolution; D002415:Cats; D002417:Cattle; D010064:Embryo Implantation; D004971:Estrus; D005260:Female; D005306:Fertilization; D005399:Fishes / Q000196:embryology; D005865:Gestational Age; D006168:Guinea Pigs; D008297:Male; D008322:Mammals / Q000196:embryology; D008431:Maternal-Fetal Exchange; D006080:Ovarian Follicle / Q000502:physiology; D010053:Ovary / Q000502:physiology; D010063:Ovum / Q000502:physiology; D010902:Pituitary Gland / Q000502:physiology; D010920:Placenta / Q000502:physiology; D010926:Placental Hormones / Q000502:physiology; D011247:Pregnancy; D011817:Rabbits; D012098:Reproduction; D014714:Vertebrates / Q000196:embryology
chemical_list: D010926:Placental Hormones