scholarly journals A Total-Group Phylogenetic Metatree for Cetacea and the Importance of Fossil Data in Diversification Analyses

2021 ◽  
Author(s):  
Graeme T Lloyd ◽  
Graham J Slater

Abstract Phylogenetic trees provide a powerful framework for testing macroevolutionary hypotheses, but it is becoming increasingly apparent that inferences derived from extant species alone can be highly misleading. Trees incorporating living and extinct taxa are are needed to address fundamental questions about the origins of diversity and disparity but it has proved challenging to generate robust, species-rich phylogenies that include large numbers of fossil taxa. As a result, most studies of diversification dynamics continue to rely on molecular phylogenies. Here, we extend and apply a recently developed meta-analytic approach for synthesizing previously published phylogenetic studies to infer a well-resolved set of species level, time-scaled phylogenetic hypotheses for extinct and extant cetaceans (whales, dolphins and allies). Our trees extend sampling from the ∼ 90 extant species to over 500 living and extinct species, and therefore allow for more robust inference of macroevolutionary dynamics. While the diversification scenarios we recover are broadly concordant with those inferred from molecular phylogenies they differ in critical ways, notably in the relative contributions of extinction and speciation rate shifts in driving rapid radiations. The metatree approach provides the most immediate route for generating higher level phylogenies of extinct taxa, and opens the door to re-evaluation of macroevolutionary hypotheses derived only from extant taxa.

2020 ◽  
Author(s):  
Graeme T. Lloyd ◽  
Graham J. Slater

AbstractPhylogenetic trees provide a powerful framework for testing macroevolutionary hypotheses, but it is becoming increasingly apparent that inferences derived from extant species alone can be highly misleading. Trees incorporating living and extinct taxa are are needed to address fundamental questions about the origins of diversity and disparity but it has proved challenging to generate robust, species–rich phylogenies that include large numbers of fossil taxa. As a result, most studies of diversification dynamics continue to rely on molecular phylogenies. Here, we extend and apply a recently developed meta–analytic approach for synthesizing previously published phylogenetic studies to infer a well–resolved set of species level, time–scaled phylogenetic hypotheses for extinct and extant cetaceans (whales, dolphins and allies). Our trees extend sampling from the ∼ 90 extant species to over 400 living and extinct species, and therefore allow for more robust inference of macroevolutionary dynamics. While the diversification scenarios we recover are broadly concordant with those inferred from molecular phylogenies they differ in critical ways, most notably in the relative contributions of extinction and speciation rate shifts in driving rapid radiations. Supertrees are often viewed as poor substitute for phylogenies inferred directly from character data but the metatree pipeline overcomes many of the past criticisms leveled at these approaches. Meta–analytic phylogenies provide the most immediate route for integrating fossils into macroevolutionary analyses, the results of which range from untrustworthy to nonsensical without them.


2005 ◽  
Vol 272 (1581) ◽  
pp. 2593-2599 ◽  
Author(s):  
Nina Rønsted ◽  
George D Weiblen ◽  
James M Cook ◽  
Nicolas Salamin ◽  
Carlos A Machado ◽  
...  

Figs ( Ficus ; ca 750 species) and fig wasps (Agaoninae) are obligate mutualists: all figs are pollinated by agaonines that feed exclusively on figs. This extraordinary symbiosis is the most extreme example of specialization in a plant–pollinator interaction and has fuelled much speculation about co-divergence. The hypothesis that pollinator specialization led to the parallel diversification of fig and pollinator lineages (co-divergence) has so far not been tested due to the lack of robust and comprehensive phylogenetic hypotheses for both partners. We produced and combined the most comprehensive molecular phylogenetic trees to date with fossil data to generate independent age estimates for fig and pollinator lineages, using both non-parametric rate smoothing and penalized likelihood dating methods. Molecular dating of ten pairs of interacting lineages provides an unparalleled example of plant–insect co-divergence over a geological time frame spanning at least 60 million years.


2011 ◽  
Vol 278 (1722) ◽  
pp. 3294-3302 ◽  
Author(s):  
Lynsey McInnes ◽  
C. David L. Orme ◽  
A. Purvis

Large complete species-level molecular phylogenies can provide the most direct information about the macroevolutionary history of clades having poor fossil records. However, extinction will ultimately erode evidence of pulses of rapid speciation in the deep past. Assessment of how well, and for how long, phylogenies retain the signature of such pulses has hitherto been based on a—probably untenable—model of ongoing diversity-independent diversification. Here, we develop two new tests for changes in diversification ‘rules’ and evaluate their power to detect sudden increases in equilibrium diversity in clades simulated with diversity-dependent speciation and extinction rates. Pulses of diversification are only detected easily if they occurred recently and if the rate of species turnover at equilibrium is low; rates reported for fossil mammals suggest that the power to detect a doubling of species diversity falls to 50 per cent after less than 50 Myr even with a perfect phylogeny of extant species. Extinction does eventually draw a veil over past dynamics, suggesting that some questions are beyond the limits of inference, but sudden clade-wide pulses of speciation can be detected after many millions of years, even when overall diversity is constrained. Applying our methods to existing phylogenies of mammals and angiosperms identifies intervals of elevated diversification in each.


2004 ◽  
Vol 359 (1450) ◽  
pp. 1551-1571 ◽  
Author(s):  
Mike Crisp ◽  
Lyn Cook ◽  
Dorothy Steane

The Australian fossil record shows that from ca . 25 Myr ago, the aseasonal–wet biome (rainforest and wet heath) gave way to the unique Australian sclerophyll biomes dominated by eucalypts, acacias and casuarinas. This transition coincided with tectonic isolation of Australia, leading to cooler, drier, more seasonal climates. From 3 Myr ago, aridification caused rapid opening of the central Australian arid zone. Molecular phylogenies with dated nodes have provided new perspectives on how these events could have affected the evolution of the Australian flora. During the Mid–Cenozoic (25–10 Myr ago) period of climatic change, there were rapid radiations in sclerophyll taxa, such as Banksia , eucalypts, pea–flowered legumes and Allocasuarina . At the same time, taxa restricted to the aseasonal–wet biome ( Nothofagus , Podocarpaceae and Araucariaceae) did not radiate or were depleted by extinction. During the Pliocene aridification, two Eremean biome taxa ( Lepidium and Chenopodiaceae) radiated rapidly after dispersing into Australia from overseas. It is clear that the biomes have different histories. Lineages in the aseasonal–wet biome are species poor, with sister taxa that are species rich, either outside Australia or in the sclerophyll biomes. In conjunction with the fossil record, this indicates depletion of the Australian aseasonal–wet biome from the Mid–Cenozoic. In the sclerophyll biomes, there have been multiple exchanges between the southwest and southeast, rather than single large endemic radiations after a vicariance event. There is need for rigorous molecular phylogenetic studies so that additional questions can be addressed, such as how interactions between biomes may have driven the speciation process during radiations. New studies should include the hitherto neglected monsoonal tropics.


Paleobiology ◽  
2015 ◽  
Vol 42 (1) ◽  
pp. 8-26 ◽  
Author(s):  
N. Adam Smith

AbstractHypotheses regarding the evolution of many clades are often generated in the absence of data from the fossil record and potential biases introduced by exclusion of paleontological data are frequently ignored. With regard to body size evolution, extinct taxa are frequently excluded because of the lack of body mass estimates—making identification of reliable clade specific body mass estimators crucial to evaluating trends on paleontological timescales. Herein, I identify optimal osteological dimensions for estimating body mass in extinct species of Pan-Alcidae (Aves, Charadriiformes) and utilize newly generated estimates of body mass to demonstrate that the combination of neontological and paleontological data produces results that conflict with hypotheses generated when extant species data are analyzed in isolation. The wing-propelled diving Pan-Alcidae are an ideal candidate for comparing estimates of body mass evolution based only on extant taxa with estimates generated including fossils because extinct species diversity (≥31 species) exceeds extant diversity, includes examples from every extant genera, and because phylogenetic hypotheses of pan-alcid relationships are not restricted to the 23 extant species. Phylogenetically contextualized estimation of body mass values for extinct pan-alcids facilitated evaluation of broad scale trends in the evolution of pan-alcid body mass and generated new data bearing on the maximum body mass threshold for aerial flight in wing-propelled divers. The range of body mass in Pan-Alcidae is found to exceed that of all other clades of Charadriiformes (shorebirds and allies) and intraclade body mass variability is recognized as a recurring theme in the evolution of the clade. Finally, comparisons of pan-alcid body mass range with penguins and the extinct †Plotopteridae elucidate potentially shared constraints among phylogenetically disparate yet ecologically similar clades of wing-propelled divers.


2016 ◽  
Vol 371 (1691) ◽  
pp. 20150225 ◽  
Author(s):  
Daniele Silvestro ◽  
Alexander Zizka ◽  
Christine D. Bacon ◽  
Borja Cascales-Miñana ◽  
Nicolas Salamin ◽  
...  

Methods in historical biogeography have revolutionized our ability to infer the evolution of ancestral geographical ranges from phylogenies of extant taxa, the rates of dispersals, and biotic connectivity among areas. However, extant taxa are likely to provide limited and potentially biased information about past biogeographic processes, due to extinction, asymmetrical dispersals and variable connectivity among areas. Fossil data hold considerable information about past distribution of lineages, but suffer from largely incomplete sampling. Here we present a new dispersal–extinction–sampling (DES) model, which estimates biogeographic parameters using fossil occurrences instead of phylogenetic trees. The model estimates dispersal and extinction rates while explicitly accounting for the incompleteness of the fossil record. Rates can vary between areas and through time, thus providing the opportunity to assess complex scenarios of biogeographic evolution. We implement the DES model in a Bayesian framework and demonstrate through simulations that it can accurately infer all the relevant parameters. We demonstrate the use of our model by analysing the Cenozoic fossil record of land plants and inferring dispersal and extinction rates across Eurasia and North America. Our results show that biogeographic range evolution is not a time-homogeneous process, as assumed in most phylogenetic analyses, but varies through time and between areas. In our empirical assessment, this is shown by the striking predominance of plant dispersals from Eurasia into North America during the Eocene climatic cooling, followed by a shift in the opposite direction, and finally, a balance in biotic interchange since the middle Miocene. We conclude by discussing the potential of fossil-based analyses to test biogeographic hypotheses and improve phylogenetic methods in historical biogeography.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1988 ◽  
Author(s):  
Sergei Tarasov ◽  
Fernando Z. Vaz-de-Mello ◽  
Frank-Thorsten Krell ◽  
Dimitar Dimitrov

Despite the increasing rate of systematic research on scarabaeine dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae), their fossil record has remained largely unrevised. In this paper, we review all 33 named scarabaeine fossils and describe two new species from Dominican amber (Canthochilum allenisp.n.,Canthochilum philipsivieorumsp.n.). We provide a catalogue of all fossil Scarabaeinae and evaluate their assignment to this subfamily, based primarily on the original descriptions but also, where possible, by examining the type specimens. We suggest that only 21 fossil taxa can be reliably assigned to the Scarabaeinae, while the remaining 14 should be treated as doubtful Scarabaeinae. The doubtful scarabaeines include the two oldest dung beetle fossils known from the Cretaceous and we suggest excluding them from any assessments of the minimum age of scarabaeine dung beetles. The earliest reliably described scarabaeine fossil appears to beLobateuchus parisii, known from Oise amber (France), which shifts the minimum age of the Scarabaeinae to the Eocene (53 Ma). We scored the best-preserved fossils, namelyLobateuchusand the twoCanthochilumspecies described herein, into the character matrix used in a recent morphology-based study of dung beetles, and then inferred their phylogenetic relationships with Bayesian and parsimony methods. All analyses yielded consistent phylogenies where the two fossilCanthochilumare placed in a clade with the extant species ofCanthochilum, andLobateuchusis recovered in a clade with the extant generaAteuchusandAphengium. Additionally, we evaluated the distribution of dung beetle fossils in the light of current global dung beetle phylogenetic hypotheses, geological time and biogeography. The presence of only extant genera in the late Oligocene and all later records suggests that the main present-day dung beetle lineages had already been established by the late Oligocene–mid Miocene.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4499 ◽  
Author(s):  
Aisha Tahir ◽  
Fatma Hussain ◽  
Nisar Ahmed ◽  
Abdolbaset Ghorbani ◽  
Amer Jamil

In pursuit of developing fast and accurate species-level molecular identification methods, we tested six DNA barcodes, namely ITS2, matK, rbcLa, ITS2+matK, ITS2+rbcLa, matK+rbcLa and ITS2+matK+rbcLa, for their capacity to identify frequently consumed but geographically isolated medicinal species of Fabaceae and Poaceae indigenous to the desert of Cholistan. Data were analysed by BLASTn sequence similarity, pairwise sequence divergence in TAXONDNA, and phylogenetic (neighbour-joining and maximum-likelihood trees) methods. Comparison of six barcode regions showed that ITS2 has the highest number of variable sites (209/360) for tested Fabaceae and (106/365) Poaceae species, the highest species-level identification (40%) in BLASTn procedure, distinct DNA barcoding gap, 100% correct species identification in BM and BCM functions of TAXONDNA, and clear cladding pattern with high nodal support in phylogenetic trees in both families. ITS2+matK+rbcLa followed ITS2 in its species-level identification capacity. The study was concluded with advocating the DNA barcoding as an effective tool for species identification and ITS2 as the best barcode region in identifying medicinal species of Fabaceae and Poaceae. Current research has practical implementation potential in the fields of pharmaco-vigilance, trade of medicinal plants and biodiversity conservation.


Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 580
Author(s):  
Hongyi Liu ◽  
Yufeng Zhang ◽  
Wei Xu ◽  
Yu Fang ◽  
Honghua Ruan

Identification based on conventional morphological characteristics is typically difficult and time-consuming. The development of molecular techniques provides a novel strategy that relies on specific mitochondrial gene fragments to conduct authentication. For this study, five newly sequenced partial mitogenomes of earthworms (Bimastos parvus, Dendrobaena octaedra, Eisenia andrei, Eisenia nordenskioldi, and Octolasion tyrtaeum) with lengths ranging from 14,977 to 15,715 were presented. Each mitogenome possessed a putative control region that resided between tRNA-Arg and tRNA-His. All of the PCGs were under negative selection according to the value of Ka/Ks. The phylogenetic trees supported the classification of Eisenia and Lumbricus; however, the trees based on cox1 did not. Through various comparisons, it was determined that cox1 fragments might be more suitable for molecular identification. These results lay the foundation for further phylogenetic studies on Lumbricidae.


Zootaxa ◽  
2010 ◽  
Vol 2648 (1) ◽  
pp. 45 ◽  
Author(s):  
PETER A. LARSEN ◽  
MARÍA R. MARCHÁN-RIVADENEIRA ◽  
ROBERT J. BAKER

Fruit-eating bats of the genus Artibeus are widely distributed across the Neotropics and are one of the most recently evolved assemblages of the family Phyllostomidae. Although the taxonomy and systematics of species of Artibeus has been the subject of an intense historical debate, the most current taxonomic arrangements recognize approximately eleven species within the genus. However, recent phylogenetic studies indicate that species diversity within South and Middle American populations of Artibeus is underestimated. South American populations referable to A. jamaicensis aequatorialis are of considerable interest because previous studies of mitochondrial DNA variation identified potential species level variation west of the Andes Mountains. In this study we use morphometric and genetic data (nuclear AFLPs) to investigate the taxonomic status of A. j. aequatorialis. Our results indicate that elevating aequatorialis to species level is appropriate based on statistically supported reciprocal monophyly in mitochondrial and nuclear datasets and diagnostic morphological characters. In light of our results, and of those presented elsewhere, we provide a revised classification of the genus.


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