Do climate-driven altitudinal range shifts explain the intraspecific diversification of a narrow ranging montane mammal, Taurus ground squirrels?

WOS: 000427518900008Understanding how species have responded to strong climatic fluctuations accompanying glacial-interglacial cycles is critical to predicting their likely responses to future climate change, and therefore can help guide conservation strategies. Using molecular phylogeography and ecological niche modelling, we aimed to understand how a newly recognized cryptic montane mammal (Spermophilus taurensis, Taurus ground squirrels) has responded to global climate changes through the Late Quaternary glacial-interglacial cycles as a means to better predict their likely responses to future climate change. Accordingly, 51 cytochrome b mitochondrial DNA sequences from throughout the known distribution of Taurus ground squirrels were used to investigate the intraspecific diversification. Besides molecular phylogeography, ecological niche modelling was also employed to get insights into possible climate-driven altitudinal range shifts in the past (the Last Glacial Maximum, 22 kya and the Mid-Holocene, 6 kya) and in the future (2050). Taurus ground squirrels survived the Late Quaternary glacial-interglacial cycles by altitudinal migrations without large geographical displacements. As warming occurred from the Last Glacial Maximum to the Mid-Holocene to the present, the potential distribution of Taurus ground squirrels shifted towards higher altitudes, resulting in a smaller range in the present. As warming continues, the potential distribution of Taurus ground squirrels will continue to shift towards higher altitudes, resulting in a much smaller range in the future. Particular sources of concern are the synergistic effects of future climate change and anthropogenic impacts on Taurus ground squirrels and their montane environments.Ahi Evran University Scientific Research Projects Coordination UnitAhi Evran University [PYO-FEN.4001.15.008]We would like to thank M. Cakir, M. Celik, H. Sevgili, and H. Yilmaz for sharing their field observations. This study was supported by the Ahi Evran University Scientific Research Projects Coordination Unit (Project Number: PYO-FEN.4001.15.008)

Controlling Parameters on Facies Geometries of the Bahamas, an Isolated Carbonate Platform Environment

The Bahamas are among the most extensively studied carbonate regions in the world, and a number of phenomena typical of calcareous environments have been first observed in the Bahamas. Early geological research in the Bahamas was undertaken by Nelson (1853B) who surveyed their geography and topography. He noticed the “remarkable lowness of profile” and the dynamics of construction and destruction of the islands, outlined the biota and lithologies, described the formation of the carbonate rocks, and noticed the eolian origin of many Bahamian islands. Forty years later, the examination of modern carbonate environments rapidly progressed with the expedition of L. and A. Agassiz in 1893 (Agassiz 1894). Their explorations focused mainly on the fringing reefs of GE Great Bahama Bank. Research on abiotic carbonate components followed, by Vaughan (1914) who emphasized that carbonate constituents can originate from both skeletal secretion and chemical precipitation, and introduced the terms “organic” and “inorganic” limestones. Black (1933) first characterized the sedimentary facies on Great Bahama Bank and noted the significance of the widespread aragonitic mud. The sand-sized calcareous components of the Bahamas and their origin, including ooid sands, were described in detail in the classic papers by Illing (1954) and Newell et al. (1960)

Hemichordate genomes and deuterostome origins.

Acorn worms, also known as enteropneust (literally, 'gut-breathing') hemichordates, are marine invertebrates that share features with echinoderms and chordates. Together, these three phyla comprise the deuterostomes. Here we report the draft genome sequences of two acorn worms, Saccoglossus kowalevskii and Ptychodera flava. By comparing them with diverse bilaterian genomes, we identify shared traits that were probably inherited from the last common deuterostome ancestor, and then explore evolutionary trajectories leading from this ancestor to hemichordates, echinoderms and chordates. The hemichordate genomes exhibit extensive conserved synteny with amphioxus and other bilaterians, and deeply conserved non-coding sequences that are candidates for conserved gene-regulatory elements. Notably, hemichordates possess a deuterostome-specific genomic cluster of four ordered transcription factor genes, the expression of which is associated with the development of pharyngeal 'gill' slits, the foremost morphological innovation of early deuterostomes, and is probably central to their filter-feeding lifestyle. Comparative analysis reveals numerous deuterostome-specific gene novelties, including genes found in deuterostomes and marine microbes, but not other animals. The putative functions of these genes can be linked to physiological, metabolic and developmental specializations of the filter-feeding ancestor