scholarly journals Spotlight on islands: on the origin and diversification of a new lineage of the Italian wall lizard Podarcis siculus in the western Pontine Islands

2018 ◽  
Author(s):  
Senczuk Gabriele ◽  
Havenstein Katja ◽  
Milana Valentina ◽  
Ripa Chiara ◽  
De Simone Emanuela ◽  
...  
Keyword(s):  
Gene Flow ◽  
Sea Level ◽  
Dna Sequences ◽  
A Priori ◽  
Phylogenetic Position ◽  
Sea Level Changes ◽  
Continental Islands ◽  
Podarcis Siculus ◽  
Pontine Islands ◽  
Italian Wall Lizard

AbstractGroups of proximate continental islands may conceal more tangled phylogeographic patterns than oceanic archipelagos as a consequence of repeated sea level changes, which allow populations to experience gene flow during periods of low sea level stands and isolation by vicariant mechanisms during periods of high sea level stands. Here, we describe for the first time an ancient and diverging lineage of the Italian wall lizard Podarcis siculus from the western Pontine Islands. We used nuclear and mitochondrial DNA sequences of 156 individuals with the aim of unraveling their phylogenetic position, while microsatellite loci were used to compare several a priori insular biogeographic models of migration with empirical data. Our results suggest that the western Pontine populations colonized the islands early during their Pliocene volcanic formation, while populations from the eastern Pontine Islands seem to have been introduced recently. The inter-island genetic makeup indicates an important role of historical migration, probably due to glacial land bridges connecting islands followed by a recent vicariant mechanism of isolation. Moreover, the most supported migration model predicted higher gene flow among islands sharing a longitudinal arrangement. Considering the threatened status of small insular endemic populations, we suggest this new evolutionarily independent unit be given priority in conservation efforts.

Predicted sea-level changes and evolutionary estimates for age of isolation in Central Mediterranean insular lizards

The Holocene ◽  
2016 ◽  
Vol 27 (3) ◽  
pp. 418-426 ◽  
Author(s):  
Pasquale Raia ◽  
Luigi Ferranti ◽  
Silvia Castiglione ◽  
Marina Melchionna ◽  
Fiorella Saggese ◽  
...  
Keyword(s):  
Sea Level ◽  
Evolutionary Rate ◽  
Biological Evolution ◽  
Optimization Procedure ◽  
Sea Level Changes ◽  
Central Mediterranean ◽  
Podarcis Siculus ◽  
S Model ◽  
Italian Wall Lizard ◽  
Insular Populations

Rates of biological evolution on islands are often presumed to exceed rates on the mainland. We tested this postulation by computing the evolutionary rate of head shape in Italian wall lizard Podarcis siculus, occurring on four islands off the coast of Southern Italy. We calculated the evolutionary rate using a phylogenetic tree whose node ages were derived from Lambeck et al. predicted ages of geographic isolation of the islands. Such ages are based on a relative sea-level change model for the late Pleistocene–Holocene. Through a likelihood optimization procedure, our method allows computing, besides the evolutionary rate, biological estimates of the ages of insular populations, with this indirectly testing Lambeck et al.’s model estimates. We found that the rate of evolution in Podarcis head shapes on islands is not statistically different from the mainland rate, although insular lizards have distinctive head shapes. Overall, the insular phenotype took 1–4000 years to arise (differing among islands). The estimated ages of insular populations are lower than Lambeck et al.’s estimates and fall in the 5- to 6-ka interval.

scholarly journals Did postglacial sea-level changes initiate the evolutionary divergence of a Tasmanian endemic raptor from its mainland relative?

2013 ◽  
Vol 280 (1773) ◽  
pp. 20132448 ◽  
Author(s):  
C. P. Burridge ◽  
W. E. Brown ◽  
J. Wadley ◽  
D. L. Nankervis ◽  
L. Olivier ◽  
...  
Keyword(s):  
Life History ◽  
Gene Flow ◽  
Body Size ◽  
Sea Level ◽  
General Assumption ◽  
Population Divergence ◽  
Evolutionary Divergence ◽  
Sea Level Changes ◽  
Marine Dispersal ◽  
Continental Islands

Populations on continental islands are often distinguishable from mainland conspecifics with respect to body size, appearance, behaviour or life history, and this is often congruent with genetic patterns. It is commonly assumed that such differences developed following the complete isolation of populations by sea-level rise following the Last Glacial Maximum (LGM). However, population divergence may predate the LGM, or marine dispersal and colonization of islands may have occurred more recently; in both cases, populations may have also diverged despite ongoing gene flow. Here, we test these alternative hypotheses for the divergence between wedge-tailed eagles from mainland Australia ( Aquila audax audax ) and the threatened Tasmanian subspecies ( Aquila audax fleayi ), based on variation at 20 microsatellite loci and mtDNA. Coalescent analyses indicate that population divergence appreciably postdates the severance of terrestrial habitat continuity and occurred without any subsequent gene flow. We infer a recent colonization of Tasmania by marine dispersal and cannot discount founder effects as the cause of differences in body size and life history. We call into question the general assumption of post-LGM marine transgression as the initiator of divergence of terrestrial lineages on continental islands and adjacent mainland, and highlight the range of alternative scenarios that should be considered.

scholarly journals The robustness of a simple dynamic model of island biodiversity to geological and eustatic change

2021 ◽  
Author(s):  
Pedro Santos Neves ◽  
Joshua W. Lambert ◽  
Luis Valente ◽  
Rampal S. Etienne
Keyword(s):  
Sea Level ◽  
Simulated Data ◽  
Oceanic Islands ◽  
Sea Level Changes ◽  
Land Bridge ◽  
Sea Level Fluctuations ◽  
Continental Islands ◽  
Island Biodiversity ◽  
And Shifts ◽  
And Sea Level

Aim: Biodiversity on islands is affected by various geo-physical processes and sea-level fluctuations. Oceanic islands (never connected to a landmass) are initially vacant with diversity accumulating via colonisation and speciation, followed by a decline as islands shrink. Continental islands have species upon formation (when disconnected from the mainland) and may have transient land-bridge connections. Theoretical predictions for the effects of these geo-processes on rates of colonisation, speciation and extinction have been proposed, but methods of phylogenetic inference assume only oceanic island scenarios without accounting for island ontogeny, sea-level changes or past landmass connections. Here, we analyse to what extent ignoring geodynamics affects the inference performance of a phylogenetic island model, DAISIE, when confronted with simulated data that violate its assumptions. Location: Simulation of oceanic and continental islands. Methods: We extend the DAISIE simulation model to include: area-dependent rates of colonisation and diversification associated with island ontogeny and sea-level fluctuations, and continental islands with biota present upon separation from the mainland, and shifts in rates to mimic temporary land-bridges. We quantify the error made when geo-processes are not accounted for by applying DAISIE's inference method to geodynamic simulations. Results: We find that the robustness of the model to dynamic island area is high (error is small) for oceanic islands and for continental islands that have been separated for a long time, suggesting that, for these island types, it is possible to obtain reliable results when ignoring geodynamics. However, for continental islands that have been recently or frequently connected, robustness of DAISIE is low, and inference results should not be trusted. Main conclusions: This study highlights that under a large proportion of island biogeographic geo-scenarios (oceanic islands and ancient continental fragments) a simple phylogenetic model ignoring geodynamics is empirically applicable and informative. However, recent connection to the continent cannot be ignored, requiring development of a new inference model.

scholarly journals Spotlight on islands: on the origin and diversification of an ancient lineage of the Italian wall lizard Podarcis siculus in the western Pontine Islands

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Gabriele Senczuk ◽  
Katja Havenstein ◽  
Valentina Milana ◽  
Chiara Ripa ◽  
Emanuela De Simone ◽  
...  
Keyword(s):  
Ancient Lineage ◽  
Podarcis Siculus ◽  
Pontine Islands ◽  
Italian Wall Lizard

Paleozoic Sea-Level Changes in the Appalachian Basin: Washington, D.C., July 20–24, 1989

10.1029/ft354 ◽  
1989 ◽  
Author(s):  
John M. Dennison ◽  
Edwin J. Anderson ◽  
Jack D. Beuthin ◽  
Edward Cotter ◽  
Richard J. Diecchio ◽  
...  
Keyword(s):  
Sea Level ◽  
Appalachian Basin ◽  
Sea Level Changes

Four Cases of Complete Melanistic Italian Wall Lizard [Podarcis siculus (Rafinesque-Schmaltz, 1810)] in Southern Italy and Sicily Island

2016 ◽  
Vol 24 (1) ◽  
pp. 63
Author(s):  
Vincenzo Reina ◽  
Filippo Spadola ◽  
Manuel Morici ◽  
Paola Sgroi ◽  
Antonino Marcianò
Keyword(s):  
Southern Italy ◽  
Podarcis Siculus ◽  
Italian Wall Lizard

CORRELATION OF THE BLACK, MARMARA AND AEGEAN SEAS DURING THE HOLOCENE

2017 ◽  
Author(s):  
Nikolay Esin ◽  
Nikolay Esin ◽  
Vladimir Ocherednik ◽  
Vladimir Ocherednik
Keyword(s):  
Mathematical Model ◽  
Sea Level ◽  
Black Sea ◽  
Aegean Sea ◽  
The Black Sea ◽  
Sea Level Changes ◽  
The Holocene

A mathematical model describing the change in the Black Sea level depending on the Aegean Sea level changes is presented in the article. Calculations have shown that the level of the Black Sea has been repeating the course of the Aegean Sea level for the last at least 6,000 years. And the level of the Black Sea above the Aegean Sea level in the tens of centimeters for this period of time.

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