Ecological niche divergence contributes species differentiation in worm lizards (Blanus sp.) (Squamata: Amphisbaenia: Blanidae) in Mediterranean part of Anatolian peninsula and the Levantine region

Ecological niche divergence or ecological niche partitioning in a widespread Neotropical bird lineage

Ecological niche divergence is generally considered to be a facet of evolution that may accompany geographic isolation and diversification in allopatry, contributing to species' evolutionary distinctiveness through time. The null expectation for any two diverging species in geographic isolation is that of niche conservatism, wherein populations do not rapidly shift to or adapt to novel environments. Here, I test ecological niche divergence for a widespread, pan-American lineage, the avian genus of martins (Progne). The genus Progne includes migrant and resident species, as well as geographically restricted taxa and widespread, intercontinentally distributed taxa, thus providing an ideal group in which to study the nature of niche divergence within a broad geographic mosaic. I obtained distributional information for the genus from publicly available databases and created ecological niche models for each species to create pairwise comparisons of environmental space. I combined these data with the most up-to-date phylogeny of Progne currently available to examine the patterns of niche evolution within the genus. I found limited evidence for niche divergence across the breeding distributions of Progne, and much stronger support for niche conservatism with patterns of niche partitioning. The ancestral Progne had a relatively broad ecological niche, like extant basal Progne lineages, and several geographically localized descendant species occupy only portions of this larger ancestral niche. I recovered strong evidence of breeding niche divergence for four of 36 taxon pairs but only one of these divergent pairs involved two widespread species (Southern Martin P. elegans vs. Gray-breasted Martin P. chalybea). Potential niche expansion from the ancestral species was observed in the most wide-ranging present-day species, namely the North American Purple Martin P. subis and P. chalybea. I analyzed populations of P. subis separately, as a microcosm of Progne evolution, and again found only limited evidence of niche divergence. This study adds to the mounting evidence for niche conservatism as a dominant feature of diversifying lineages, and sheds light on the ways in which apparently divergent niches may arise through allopatry while not involving any true niche shifts through evolutionary time. Even taxa that appear unique in terms of habitat or behavior may not be diversifying with respect to their ecological niches, but merely partitioning ancestral niches among descendant taxa.

Ecological niche divergence or ecological niche partitioning in a widespread Neotropical bird lineage

Ecological niche divergence is generally considered to be a facet of evolution that may accompany geographic isolation and diversification in allopatry, contributing to species' evolutionary distinctiveness through time. The null expectation for any two diverging species in geographic isolation is that of niche conservatism, wherein populations do not rapidly shift to or adapt to novel environments. Here, I test ecological niche divergence for a widespread, pan-American lineage, the avian genus of martins (Progne). Despite containing species with distributions that go from continent-spanning to locally endemic, I found limited evidence for niche divergence across the breeding distributions of Progne, and much stronger support for niche conservatism with patterns of niche partitioning. The ancestral Progne had a relatively broad ecological niche, similar to extant basal Progne lineages, and several geographically localized descendant species occupy only portions of the larger ancestral Progne niche. I recovered strong evidence of breeding niche divergence for four of 36 taxon pairs but only one of these divergent pairs involved two widespread, continental species (Southern Martin P. elegans vs. Gray-breasted Martin P. chalybea). Potential niche expansion from the ancestral species was observed in the most wide-ranging present-day species, namely the North American Purple Martin P. subis and P. chalybea. I analyzed populations of P. subis separately, as a microcosm of Progne evolution, and again found only limited evidence of niche divergence. This study adds to the mounting evidence for niche conservatism as a dominant feature of diversifying lineages. Even taxa that appear unique in terms of habitat or behavior may still not be diversifying with respect to their ecological niches, but merely partitioning ancestral niches among descendant taxa.

The genus Blanus (Reptilia: Blanidae) in Iraq: distribution, species identification and genetic affiliation

N/A.

A Contribution to the Biogeography of Ablepharus anatolicus and A. budaki (Squamata: Scincidae) Using Ecological Niche Modeling in Turkey

The Anatolian Peninsula is very richly biodiverse in terms of its location and with new studies, this wealth has gradually increased as new taxa of Anatolian origin are added to the literature. Ablepharus budaki and A. anatolicus, formerly considered to be subspecies of A. kitaibelli and A. budaki respectively, are spread throughout the southern part of Anatolia. Although recent phylogenetic and morphological studies revealed their species status, no information was given about the relation of the species with each other in terms of ecological niche. In this study, our primary goal was to discover whether the niches of these two taxa were different from each other. Considering the analyses made within the scope of this study, it has been revealed that both A. anatolicus and A. budaki are different from each other in terms of their ecological niche. However, since these two taxa have very small contact regions, an example of parapatric speciation, and their distribution areas cover almost completely different geographies, we can say that they have different ecological niche requirements, according to the results of this study. As a result, this study supported the findings in literature and the idea that these taxa are two different species

Fine-scale analysis of habitat occupancy by Kura lizard (Darevskia portschinskii) and its daughter parthenogenetic form (Darevskia dahli)

Two species of rock lizards, the parthenogenetic D. dahli and the sexually reproducing D. portschinskii, coexist in a rocky outcrop in an area of ca. 1 ha, in the vicinity of Tbilisi, Georgia; the location has been well-known since the middle 1960s. The population density of the parthenogenetic lizard is five times higher than that of the sexual breeder. We studied the distribution of active lizards in space and time over three consecutive years, during the spring and autumn activity periods, to explore spatial and temporal differences between the species on a fine spatial scale. We studied the influence of temperature, humidity, and quantitative characteristics of the surface and the distance from permanent water source on the spatial distribution of D. dahli and D. portschinskii. Darevskia portschinskii was less dependent on the distance from the water source and more evenly distributed in space and time than D. dahli. Despite potential competitive interactions, the species did not avoid each other on the microhabitat scale, suggesting that the observed ecological differences are not caused by a niche shift. More individuals of the sexual breeder than individuals of the parthenogen were found in suboptimal habitats. This feature may increase the evolutionary success of D. portschinskii in a long-term perspective.