Convergent adaptive radiations in Madagascan and Asian ranid frogs reveal covariation between larval and adult traits

Abstract

Recent studies have reported that independent adaptive radiations can lead to identical ecomorphs. Our phylogenetic analyses of nuclear and mitochondrial DNA sequences here indicate that a major radiation of ranid frogs on Madagascar produced morphological, physiological, and developmental characters that are remarkably similar to those that independently evolved on the Indian subcontinent. We demonstrate further that, in several cases, adult and larval stages each evolved sets of characters which are not only convergent between independent lineages, but also allowed both developmental stages to invade the same adaptive zone. It is likely that such covariations are produced by similar selective pressures on independent larval and adult characters rather than by genetic or functional linkage. We briefly discuss why larval͞adult covariations might constitute an important evolutionary phenomenon in species for which more than one developmental stage potentially has access to multiple environmental conditions.

The phylogenetic position and diversity of the enigmatic mongrel frog Nothophryne Poynton, 1963 (Amphibia, Anura)

“…In fact, the genus Bossuyt and Milinkovitch, 2000 and references therein, e.g., Glaw et al, 1998). This example shows how parallelism in morphological traits can cause taxonomic confusion.…”

Partial island submergence and speciation in an adaptive radiation: a multilocus analysis of the Cuban green anoles

“…The nuclear gene encoding the visual pigment rhodopsin is useful for phylogenetic analyses (Bossuyt & Milinkovitch 2000;Page 2000;Birks & Edwards 2002;Chen et al 2003;Veith et al 2003) and occurs as a single copy in A. carolinensis, a close relative of A. porcatus and A. allisoni (Kawamura & Yokoyama 1994). Here, we examine the third intron and portions of the flanking exon sequence for this gene.…”

Adaptive Radiation, Ecological Opportunity, and Evolutionary Determinism

“…As a result, when species from such clades experience the same selective conditions, they may adapt in genetically and developmentally similar ways (Haldane 1932;Gould 2002;Hoekstra 2006). Recent studies have provided many examples in which parallel phenotypic change in closely related species (or populations of the same species) is caused by similar genetic changes in a wide range of organisms and traits (e.g., Sucena et al 2003;Colosimo et al 2005;Hoekstra et al 2006;Protas et al 2006;Shapiro et al 2006;Whittall et al 2006;Baxter et al 2008;Gross et al 2009;Chan et al 2010; of course, this is not always the case: sometimes convergent phenotypic evolution is accomplished by different genetic changes, even in closely related species [e.g., Hoekstra and Nachman 2003;Wittkopp et al 2003;Hoekstra et al 2006;Kingsley et al 2009] Bossuyt and Milinkovitch 2000;Ruedi and Mayer 2001;Stadelmann et al 2007), and the examples that have been suggested require further examination to assess the extent of species-forspecies matching (Losos 2009). Radiations occurring on different continents usually will be accomplished by distantly related clades that are, for reasons just discussed, likely to diversify in different ways (Pianka 1986;Cadle and Greene 1993;Losos 1994).…”