0198566123.pdf

Studies of island biotas are important because the rela- tionships among distribution, speciation, and adaptation are easier to ...

The significance of anagenesis as a model of island evolutionary change may well have been over- looked given the obvious fascin ...

Samoa. Wilson bundled the species into three stages. Stage 1 species are those that dominate in the marginal habitats: open lowl ...

a secondary stage 1 species, and expanding in its distribution (Fig. 9.2). Caribbean birds Ricklefs and Cox (1972) put forward a ...

part of the mechanism for the cycle as put forward by Ricklefs and Cox (1972) was the evolutionary reaction, or counter-adaptati ...

widespread and abundant, contrary to the original model. Ricklefs and Cox (1978) took this as illus- trating that species on Jam ...

that conditions of climate and habitat were appreciably different during the last glacial period and indeed earlier in the Pleis ...

model. Multiple colonization, as exemplified by the yellow warbler, occurred in a few other cases, but overall the results provi ...

which is subdivided into two series at the next level of the hierarchy (Fig. 9.4). The wattsi seriescomprise small brown lizards ...

competition and accidental introductions of anoles serve to demonstrate that an invader very similar in size to an established r ...

radiation is distinguished by niche differentiation amongst the members of the lineage. As we have seen, selection and adaptatio ...

and Wilson (1963, 1967) termed such peripheral areas the radiation zone. Here the low diversity of colonists, and the disharmony ...

1500 mASL, but most of the islands are relatively low. Volcanic in origin, they are true oceanic islands, never having been conn ...

ADAPTIVE RADIATION 221 Scratch for seeds on the ground Feed on seeds on the ground and the flowers and pulp of Prickly Pear(Opun ...

random genetic changes, drift, and selection (e.g. for different feeding niches). A degree of differentiation would then have be ...

and tongues; thus providing one of the most popu- lar illustrations of evolutionary radiation (Fig. 9.6; Carlquist 1974; William ...

sanguinea(the apapane) and Vestiaria coccinea(the i’iwi), two of the more widespread taxa, show an intriguing lack of differenti ...

also been observed between the Galápagos land and marine iguanas which, although of mono- phyletic origin, are actually placed i ...

226 EMERGENT MODELS OF ISLAND EVOLUTION (^0100) 200 km N Oahu Kauai (4) (13) Maui complex (12) Hawaii (7) Oahu Kauai (29) (12) M ...

ADAPTIVE RADIATION 227 Box 9.1 Canarian spiders, beetles, and snails The Canarian invertebrates provide an outstanding example o ...