Macroevolutionary patterns in the diversification of parrots: effects of climate change, geological events and key innovations

Abstract

Aim Parrots are thought to have originated on Gondwana during the Cretaceous. The initial split within crown group parrots separated the New Zealand taxa from the remaining extant species and was considered to coincide with the separation of New Zealand from Gondwana 82-85 Ma, assuming that the diversification of parrots was mainly shaped by vicariance. However, the distribution patterns of several extant parrot groups cannot be explained without invoking transoceanic dispersal, challenging this assumption. Here, we present a temporal and spatial framework for the diversification of parrots using external avian fossils as calibration points in order to evaluate the relative importance of the influences of past climate change, plate tectonics and ecological opportunity.Location Australasian, African, Indo-Malayan and Neotropical regions.Methods Phylogenetic relationships were investigated using partial sequences of the nuclear genes c-mos, RAG-1 and Zenk of 75 parrot and 21 other avian taxa. Divergence dates and confidence intervals were estimated using a Bayesian relaxed molecular clock approach. Biogeographic patterns were evaluated taking temporal connectivity between areas into account. We tested whether diversification remained constant over time and if some parrot groups were more species-rich than expected given their age.Results Crown group diversification of parrots started only about 58 Ma, in the Palaeogene, significantly later than previously thought. The Australasian lories and possibly also the Neotropical Arini were found to be unexpectedly speciesrich. Diversification rates probably increased around the Eocene/Oligocene boundary and in the middle Miocene, during two periods of major global climatic aberrations characterized by global cooling.Main conclusions The diversification of parrots was shaped by climatic and geological events as well as by key innovations. Initial vicariance events caused by continental break-up were followed by transoceanic dispersal and local radiations. Habitat shifts caused by climate change and mountain orogenesis may have acted as a catalyst to the diversification by providing new ecological opportunities and challenges as well as by causing isolation as a result of habitat fragmentation. The lories constitute the only highly nectarivorous parrot clade, and their diet shift, associated with morphological innovation, may have acted as an evolutionary key innovation, allowing them to explore underutilized niches and promoting their diversification.

Chromosomal Evolution in Psittaciformes. Revisited

“…Australian family Cacatuidae is the next group to diverge from the main group of Psittaciformes, apparently in sympatric coexistence with other parrot lineages (Astuti, Azuma, Suzuki, & Higashi, 2006;Mayr, 2010;Schweizer et al, 2011;White et al, 2011;Wright et al, 2008). Their basal diversification during the Oligocene, and ulterior radiation in early to middle Miocene has been well documented (Pacheco et al, 2011;Rheindt et al, 2014;Schweizer et al, 2011;White et al, 2011).…”

“…Their basal diversification during the Oligocene, and ulterior radiation in early to middle Miocene has been well documented (Pacheco et al, 2011;Rheindt et al, 2014;Schweizer et al, 2011;White et al, 2011).…”

“…Early divergence of New Zealand Strigopidae parrots: kea (Nestor notabilis), kaka (Nestor meridionalis) (Tribe Nestorini) and kakapo (Strigops habroptilus) (Tribe Strigopini), has been (not unanimously) correlated to the Cretaceous separation of New Zealand from Gondwana 82-85 MYA (Pacheco et al, 2011;Rheindt et al, 2014;Schweizer et al, 2010Schweizer et al, , 2011Tavares et al, 2006;Wright et al, 2008), and it was cautiously assumed to be caused by vicariance (de Kloet & de Kloet, 2005;Wright et al, 2008), although alternative scenarios are contemplated (Pacheco et al, 2011;Rheindt et al, 2014;Schweizer et al, 2011;White et al, 2011).…”

“…Molecular genomic results seem to indicate an Eocene divergence of Psittaciformes in three basal lineages (Pacheco et al, 2011;Rheindt et al, 2014;Schweizer et al, 2010Schweizer et al, , 2011Tavares, Baker, Pereira, & Miyaki, 2006;Wright et al, 2008), which correspond to the most recent taxonomical classification of the order in three families; Strigopidae, Cacatuidae and Psittacidae (Winkler et al, 2015).…”

Diversification patterns in the North Andean Block: a perspective from biogeographical hypotheses

“…The diversification in the NAB also is studied under a temporal stratification separating the Miocene-Pliocene (23.03-2.5 Ma) time frame from the early Pliocene-Pleistocene (2.59-0.01 Ma) (Velazco and Patterson, 2008;Schweizer et al, 2011;Benham et al, 2014). Chazot et al 2016 proposed a framework of biogeographic scenarios containing four main evolutionary mechanisms (speciation, extinction, older colonisation times, and migration) to investigate variation in diversity between Andean and non-Andean regions using the subtribe Godyridina.…”