Viviparous placentotrophy in reptiles and the parent–offspring conflict

摘要: In placentotrophic viviparous reptiles, pregnant females deliver nutrients to their developing fetuses by diverse morphological specializations that reflect independent evolutionary origins. A survey of these reveals a major emphasis on histotrophy (uterine secretion and fetal absorption) rather than hemotrophy (transfer between maternal blood streams). Of available hypotheses for the prevalence histotrophic transfer, most promising derives insights from theoretical parent-offspring conflict over nutrient investment. I suggest gives greater control synthesis, storage, delivery hemotrophic reflecting preeminence in any potential competition One lizard species shows invasive ovo-implantation direct contact tissues vessels, potentially conferring transfer embryo. Future research squamates will benefit application theory transition incipient substantial matrotrophy, as well testing theory-derived predictions both facultatively highly forms.