Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2001 Mar;23(3):233-41.
doi: 10.1002/1521-1878(200103)23:3<233::AID-BIES1033>3.0.CO;2-Q.

Frogs Without Polliwogs: Evolution of Anuran Direct Development


Frogs Without Polliwogs: Evolution of Anuran Direct Development

E M Callery et al. Bioessays. .


Direct development is the assumption of the adult morphology without progression through an intervening, morphologically distinct, free-living larval phase. We discuss the ecological factors contributing to the evolution of this derived life-history strategy in frogs, and the developmental modifications that facilitate such an unusual mode of embryogenesis. Studies on the Puerto Rican tree frog, Eleutherodactylus coqui, have identified several such modifications, including developmental adaptations for dealing with increased egg size, and loss of tadpole structures. Surprisingly, this direct developer still undergoes a thyroid hormone-dependent metamorphosis, which occurs before hatching. We suggest how the ancestral biphasic developmental pattern may have been rearranged during the evolution of direct development.

Similar articles

See all similar articles

Cited by 12 articles

See all "Cited by" articles

Publication types

LinkOut - more resources