Exaptation Once viviparity has evolved for thermal reasons (presum- of advantages as stimulated the origin of the trait (in this case, maternal thermoregulation) or by different factors (i.e., exaptation). Viviparous reptiles have been used as model species for many studies that seek to explain the evolution of viviparity. Viviparity might enhance fitness in … Plants such as some Iridaceae and Agavoideae grow cormlets in the axils of their inflorescences. In reptiles, the … The evolution of matrotrophy (i.e., direct supply of nutrients by the mother during gestation) may be associated with high maternal energy availability during gestation. In some species this seems to have gone back and forth in their evolutionary history, which suggests that changing conditions favour one then the other at different times, possibly … To our knowledge, however, the short-tailed pit-viper ( Gloydius brevicaudus ) is the only viviparous reptile for which the ratio of residual yolk dry … The costs and benefits of matrotrophy in viviparous reptiles 5 1-4. Ovoviviparity: In this mode of internal fertilization, eggs are retained in female and the embryo receives nourishment … Viviparity advantages. Viviparity: In this mode of internal fertilization, the young ones develop inside the mother and receive nourishment through the placenta. 5. 2. increases the length of time the eggs are kept in the oviduct. Phylogenetic transitions from oviparity to viviparity in reptiles generally have occurred in cold climates, apparently driven by selective advantages accruing from maternal regulation of incubation temperature. Evolution of viviparous reproduction in Paleozoic and Mesozoic reptiles DANIEL G. BLACKBURN*,1 and CHRISTIAN A. SIDOR2 1Department of Biology and Electron Microscopy Center, Trinity College, Hartford, CT and 2Department of Biology and Burke Museum, University of Washington, Seattle, WA, USA ABSTRACT Although viviparity … Viviparity has evolved from ancestral oviparity at least 115 times in squamate reptiles [1,2].Reversals from viviparity to oviparity are rare [3–6], yet recent phylogenetic work suggesting frequent reversals [] has rekindled debate about their adaptive significance for squamate evolution.Dollo's Law of … 6. The vast majority of such studies have focused on the advantage viviparity provides with regards to maternal control of embryonic developmental temperature. Evolution of viviparity in reptiles 2 1-2. However, we lack knowledge about the selective advantages of matrotrophic viviparity (live-bearing) in reptiles. Snakes and lizards have thus provided popular model organisms for analysis of the selective pressures involved in this major … In viviparity the young develop within the female, receiving nourishment from the mother’s blood through a placenta. Oviparity to viviparity to placentotrophy. Furthermore, selective forces in the evolution of viviparity in reptiles may be … All of the above. This work has broadly supported the feasibility of many assumptions underpinning the “cold-climate” hypothesis outlined above (Shine 1983, 2002a). These fall and in favourable circumstances they have effectively a whole season's start over fallen seeds. Viviparity has arisen in many oviparous reptile lineages that have invaded colder climates. Terrestrial origins of viviparity in Mesozoic marine reptiles may be a departure from the conventional wisdom. 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