The evolution of viviparity
in amniote vertebrates: egg retention versus egg size reduction.
is the reproductive strategy of these fishes (Koya et al.
Some immunological and endocrineological problems raised by the evolution of viviparity
25) A series of knockout mouse studies on these genes has gathered persuasive evidence that at least some of these genes are essential in the current form of the developmental and reproductive systems, which suggests that they made critical contributions to mammalian evolution in a variety of ways, such as the establishment of viviparity
(22-26) and presumably certain sophisticated brain functions.
This genus inhabits mainly lowland forests and evolved with a group of specializations related to viviparity
, which are unique among reptiles and convergent only with placental mammals: a long period of gestation (9 to 12 months) and microlecithal eggs (0.
The down-side of viviparity
is that parent trees must 'invest' a great deal more energy in producing fewer numbers of developed seedlings.
Convergent evolution of viviparity
, matrotrophy, and specializations for fetal nutrition in reptiles and other vertebrates.
Because the remaining eggs are unincubated, this condition has been classified as simultaneous viviparity
(Meier et al.
Live bearing in Cretaceous marine lizards: first fossil record of viviparity
In Reproductive biology and phylogeny of fishes (agnathans and bony fishes): phylogeny, reproductive system, viviparity
Researchers from the University of Exeter and the University of Lincoln investigated the hypotheses that historical invasions of cold climates by Liolaemus lizards - one of the most diverse groups of vertebrates on earth - have only been possible due to their evolution to viviparity
(live birth) from oviparity (laying eggs).
The difference in diets between males and females may be related to the viviparous reproductive strategy (matrotrophic viviparity
with trophonemata) used by freshwater stingrays (Charvet-Almeida et al.