Quaternary geology of the Amazonian Lowland

Irion, Georg; Müller, Jens Daniel; Mello, J. Nunes de; Junk, Wolfgang J.

doi:10.1007/bf01204460

Cited by 79 publications

(56 citation statements)

References 20 publications

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“…On the Brazilian shield, the ''damming-back effect'' promoted by impounded lakes caused the enlargement of the width of rivers with great discharge such as the Tocantins, Xingú , and Tapajó s. The earliest split in the X. spixii/elegans superespecies (between the sister species X. spixii and X. elegans), estimated as being completed by about three million years ago, could have been initiated by an extensive embayment of the Tapajó s river in a period of high sea levels during the late Pliocene, when impounded lakes covered the lower Amazon (Irion et al 1995). In contrast, the western Amazonian lowlands, because of their lower elevation and poorer draining conditions, were more strongly flooded by periods of high sea levels than the Brazilian shield.…”

Section: Resultsmentioning

confidence: 99%

“…In contrast, the western Amazonian lowlands, because of their lower elevation and poorer draining conditions, were more strongly flooded by periods of high sea levels than the Brazilian shield. It is postulated that the western Amazonian lowlands were covered extensively by floodplain forests until the Pleistocene (Irion et al 1995), therefore potentially explaining the fairly late estimated colonization of this area by lineages of a terra-firme organism such as the X. spixii/elegans superspecies (Middle Pleistocene). Distinct impacts of sea level rises on different parts of Amazonia can thus also contribute to explain the observed lack of a river effect in southwestern Amazonia, as opposed to a strong river effect on the Brazilian shield.…”

Section: Resultsmentioning

confidence: 99%

“…The lack of a river effect in the western part of the Amazon, when compared to its central and eastern parts, is probably explained by the younger age of the western Amazonian lowlands. Although the Brazilian and Guianan shields have been geologically stable for the last 30-50 million years (Irion et al 1995), the southwestern part of Amazonia began to take its current shape only in the last 2.5 million years or so (Late Pliocene; Hoorn et al 1995;Campbell et al 2001). Therefore, western Amazonian rivers are younger and less stable than rivers located on the Brazilian shield, and they experience frequent lateral channel migration responsible for across river transfer of large pieces of land (Salo et al 1986;Colwell 2000).…”

Section: The Riverine Barrier Hypothesismentioning

confidence: 99%

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Historical Diversification of a Terra-Firme Forest Bird Superspecies: A Phylogeographic Perspective on the Role of Different Hypotheses of Amazonian Diversification

2004

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Abstract. Among those few hypotheses of Amazonian diversification amenable to falsification by phylogenetic and population genetics methods, three can be singled out because of their general application to vertebrates: the riverine barrier, the refuge, and the Miocene marine incursion hypotheses. I used phylogenetic and population genetics methods to reconstruct the diversification history of the upland (terra-firme) forest superspecies Xiphorhynchus spixii/elegans (Aves: Dendrocolaptidae) in Amazonia, and to evaluate predictions of the riverine barrier, refuge, and Miocene marine incursion hypotheses. Phylogeographic and population genetics analyses of the X. spixii/elegans superspecies indicated that the main prediction of the riverine barrier hypothesis (that sister lineages occur across major rivers) hold only for populations separated by ''clear-water'' rivers located on the Brazilian shield, in central and eastern Amazonia; in contrast, ''white-water'' rivers located in western Amazonia did not represent areas of primary divergence for populations of this superspecies. The main prediction derived from the refuge hypothesis (that populations of the X. spixii/elegans superspecies would show signs of past population bottlenecks and recent demographic expansions) was supported only for populations found in western Amazonia, where paleoecological data have failed to support past rainforest fragmentation and expansion of open vegetation types; conversely, populations from the eastern and central parts of Amazonia, where paleoecological data are consistent with an historical interplay between rainforest and open vegetation types, did not show population genetics attributes expected under the refuge hypothesis. Phylogeographic and population genetics data were consistent with the prediction made by the Miocene marine incursion hypothesis that populations of the X. spixii/elegans superspecies found on the Brazilian shield were older than populations from other parts of Amazonia. In contrast, the phylogeny obtained for lineages of this superspecies falsified the predicted monophyly of Brazilian shield populations, as postulated by the Miocene marine incursion hypothesis. In general, important predictions of both riverine barrier and Miocene marine incursion hypotheses were supported, indicating that they are not mutually exclusive; in fact, the data presented herein suggest that an interaction among geology, sea level changes, and hydrography created opportunities for cladogenesis in the X. spixii/elegans superspecies at different temporal and geographical scales.Key words. Aves, Amazonia, Miocene marine incursion hypothesis, phylogeography, population genetics, refuge hypothesis, riverine barrier hypothesis.Received March 10, 2003. Accepted February 10, 2004 The bird fauna of the Amazon lowlands in South America is the richest in the world, with over 1000 species, of which about 265 are endemic (Stotz et al. 1996;Nores 2000). As early as 1852, the British naturalist Alfred Russel Wallace put forward an evolutionary...

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: The Riverine Barrier Hypothesismentioning

confidence: 99%

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Historical Diversification of a Terra-Firme Forest Bird Superspecies: A Phylogeographic Perspective on the Role of Different Hypotheses of Amazonian Diversification

2004

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“…Several authors support marine transgression in Amazonia (e.g., Campbell, 1990;Frailey et al, 1988;Hoorn, 1994;Hoorn et al, 1995;Irion, 1984;Irion et al, 1995). This hypothesis became particularly attractive after publications that recorded marine transgression in Western Amazonia during the late Miocene, with the establishment of an interior seaway derived from the Pacific and/or Caribean sea (Räsänen et al, 1995).…”

Section: Implication Of Geological Factors In the Evolution Of The Ammentioning

confidence: 99%

New geological framework for Western Amazonia (Brazil) and implications for biogeography and evolution

2005

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Although many of the current hypotheses to explain the origin and distribution of the Amazon biodiversity has been based directly or indirectly on geological data, the reconstruction of the geological history of the Amazon region is still inadequate to analyze its relationship with the biodiversity. This work has the main goal to characterize the sedimentary successions formed in the Brazilian Amazon in the NeogeneQuaternary discussing the evolution of the depositional systems through time and analyzing their main controlling mechanisms in order to fill up this gap. Radar image interpretation, sedimentological studies, and radiocarbon dating allowed the mapping of Plio-Pleistocene to Holocene units along the Solimõ es-Amazonas River, Brazil. This integrated work led to the characterization of five sedimentary successions overlying Miocene deposits of the Solimõ es/Pebas Formation, which include the following: Içá Formation (Plio-Pleistocene), deposits Q1 (37,400-43,700 14 C yr B.P.), deposits Q2 (27,200 14 C yr B.P.), deposits Q3 (6730-2480 14 C yr B.P.), and deposits Q4 (280-130 14 C yr B.P.). These deposits occur mostly to the west of Manaus, forming NW-SE elongated belts that are progressively younger from SW to NE, indicating a subsiding basin with a depocenter that migrated to the NE. The reconstruction of the depositional history is consistent with significant changes in the landscapes. Hence, the closure of a large lake system at the end of the Miocene gave rise to the development of a Plio-Pleistocene fluvial system. This was yet very distinct from the modern drainage, with shallow, energetic, highly migrating, braided to anastomosed channels having an overall northeast outlet. This fluvial system formed probably under climatic conditions relatively drier than today's. During the early Pleistocene, there was pronounced erosion, followed by a renewed depositional phase ca. 40,000 14 C yr B.P., with the development of prograding lobes and/or crevasse splays associated with a lake system (i.e., fan-delta) and/or fluvial flood plain areas. After a period of erosion, a fluvial system with eastward draining channels started to develop at around 27,000 14 C yr B.P. The fluvial channels were overflooded in midHolocene time. This flooding is attributed to an increased period of humidity, with a peak between 5000 and 2500 14 C yr B.P. The data presented herein support that, rather than being a monotonous area, the Amazonia was a place with frequent changes in landscape throughout the Neogene-Quaternary, probably as a result of climatic and tectonic factors. We hypothesize that these changes in the physical environment stressed the biota, resulting in speciation and thus had a great impact on modern biodiversity.

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“…Miocene and the formation of the current Amazon River's drainage 2-Island model by recurrent Miocene marine introgressions caused by fluctuations of world sea-level and the appearance of internal Amazonian lakes 3-Appearance of geological arches, which changed the geomorphology of the Amazonian basin 1- [113,120,121,234] 2- [163] 3- [3,12,111,133,170] Riverine Barrier hypothesis, RBH The largest rivers of the Amazonian Basin formed in the late Miocene as a barrier to the dispersion of organisms [235,236] Recent lagoon hypothesis, RLH…”

Section: -Uplift Of the Northern Andes In The Latementioning

confidence: 99%

Continuous Miocene, Pliocene and Pleistocene Influences on Mitochondrial Diversification of the Capybara (Hydrochoerus Hydrochoeris; Hydrochoeridae, Rodentia): Incapacity to Determine Exclusive Hypotheses on the Origins of the Amazon and Orinoco Diversity for This Species

Ruiz‐García¹,

Luengas-Villamil²,

Pinedo-Castro³

et al. 2016

J Phylogenetics Evol Biol

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The capybara (Hydrochoerus hydrochoeris) is the largest rodent on the world and it is strongly linked to the river systems of a large fraction of South America and part of Central America (Panama). Thus, it is an interesting species to test hypotheses about the origin of the high biodiversity within the Amazon Basin and in a sizeable fraction of the Neotropics. To test these hypotheses, we sequenced two mitochondrial genes (control region and Cytochrome b) of 78 wild capybaras sampled in Colombia, Peru, Ecuador and Brazil. At least, five different "populations" or ESUs were detected in well delimited geographical areas. However, our results do not support the more recent view that two different species of capybara are present (H. hydrochoeris and H. isthmus), unless chromosomal speciation (stasipatric or parapatric) can be demonstrated between these two groups. A Bayesian tree with the aforementioned two mitochondrial genes, and another Bayesian tree with a subset of 25 capybaras for 10 mitochondrial genes, showed that the initial diversification of the mitochondrial haplotype in capybaras was initiated in the Late Miocene. The trees also showed that the other haplotype diversification processes extended into the Pliocene and Pleistocene. We also detected population expansion events during different moments of the Pleistocene. Although some authors strongly suggest that the Miocene diversification explains the extreme biodiversity in the Amazon Basin and in surroundings areas (for instance, the Paleogeography hypothesis), others consider it the result of available forest refugia (Refuge hypothesis) during the Pleistocene. However, our results suggest that both hypotheses (and others, such as the Riverrefuge, the Recent Lagoon and the Hydrogeological Recent Change hypotheses) could have affected the evolution of the capybara to generate the current mitochondrial diversity. Thus, it is difficult to generalize a unique Amazon biota diversification hypothesis because each species or taxon could be affected by different processes and because the temporal antiquity of each taxon in South America is also different. Many mammalian taxa, and others, migrated into South America during the Great American Biotic Interchange (GABI) and their diversification processes in South America were mainly driven by Pleistocene events as those proposed by the Refuge hypothesis. Older taxa within this continent could have begun their current genetics diversification processes earlier, such as in the case of the capybara.

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Quaternary geology of the Amazonian Lowland

Cited by 79 publications

References 20 publications

Historical Diversification of a Terra-Firme Forest Bird Superspecies: A Phylogeographic Perspective on the Role of Different Hypotheses of Amazonian Diversification

Historical Diversification of a Terra-Firme Forest Bird Superspecies: A Phylogeographic Perspective on the Role of Different Hypotheses of Amazonian Diversification

New geological framework for Western Amazonia (Brazil) and implications for biogeography and evolution

Continuous Miocene, Pliocene and Pleistocene Influences on Mitochondrial Diversification of the Capybara (Hydrochoerus Hydrochoeris; Hydrochoeridae, Rodentia): Incapacity to Determine Exclusive Hypotheses on the Origins of the Amazon and Orinoco Diversity for This Species

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