The Role of Physical Barriers in the Location of Avian Suture Zones in the Guiana Shield, Northern Amazonia

Tangled banks: A landscape genomic evaluation of Wallace's Riverine barrier hypothesis for three Amazon plant species

“…Dispersal barriers have played a pervasive role in species diversification and shaping patterns of genetic diversity for a plethora of species worldwide (e.g., Boubli et al., ; Naka, Bechtoldt, Henriques, & Brumfield, ; Nazareno, Dick, & Lohmann, ; Peres, Patton, & da Silva, ). Almost two centuries ago, Wallace () proposed the Riverine Barrier hypothesis based on observations of monkey species distributions in the Amazon Basin.…”

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“…lack of genetic differentiation across the river and little to no genetic structure along the valley) were also obtained in a recent study on brown spider monkeys (Ateles hybridus; Link et al 2015). Gene flow across large rivers that may represent insurmountable barriers in their lower reaches may occur readily near their headwaters (Capparella 1988, Ayres and Clutton-Brock 1992, Peres et al 1996, Gascon et al 1998, Gehring et al 2012, Naka et al 2012); indeed, a recent study showed that distinct populations of Amazonian birds meet and hybridize in the headwater regions of the Tapajós, a major river known to promote population divergence (Weir et al 2015). Thus, the lack of population differentiation across the Magdalena River may be explained by dispersal across its narrow headwaters.…”

“…Considering that several rivers in the Neotropical region-some of which are not particularly large-are known to act as geographic barriers for birds (Ribas et al 2012, Naka et al 2012, Maldonado-Coelho et al 2013, Fernandes et al 2014) and other vertebrates (Gascon et al 1996, Fouquet et al 2012, why is it that it that the Magdalena River does not act as a barrier to gene flow among populations, despite it being the largest river west of the Andes in South America? Our results are not unique to birds, because similar findings (i.e.…”

Taxonomia, filogenia e distribuição de Cercomacra Sclater, 1858 (Aves: Thamnophilidae)

“…Embora apenas caracteres vocais qualitativos indiquem a diagnose das espécies ao sul da Amazônia, a importância da vocalização de thamnofilídeos para a manutenção das espécies já foi demonstrada com sucesso (ISLER et al, 1998), e distâncias genéticas (tipicamente encontradas entre espécies incontestáveis) entre espécies desta família com diferenças imperceptíveis na plumagem, mas com vocalizações distintas, foram comprovadas (BATES et al, 1999;ISLER et al, 2007 (NAKA et al, 2012).…”