Francisco Ferri-Yáñez

Heat freezes niche evolution

Climate change is altering phenology and distributions of many species and further changes are projected. Can species physiologically adapt to climate warming? We analyse thermal tolerances of a large number of terrestrial ectotherm (n = 697), endotherm (n = 227) and plant (n = 1816) species worldwide, and show that tolerance to heat is largely conserved across lineages, while tolerance to cold varies between and within species. This pattern, previously documented for ectotherms, is apparent for this group and for endotherms and plants, challenging the longstanding view that physiological tolerances of species change continuously across climatic gradients. An alternative view is proposed in which the thermal component of climatic niches would overlap across species more than expected. We argue that hard physiological boundaries exist that constrain evolution of tolerances of terrestrial organisms to high temperatures. In contrast, evolution of tolerances to cold should be more frequent. One consequence of conservatism of upper thermal tolerances is that estimated niches for cold-adapted species will tend to underestimate their upper thermal limits, thereby potentially inflating assessments of risk from climate change. In contrast, species whose climatic preferences are close to their upper thermal limits will unlikely evolve physiological tolerances to increased heat, thereby being predictably more affected by warming.

Combined Effects of the North Atlantic Oscillation and the Arctic Oscillation on Sea Surface Temperature in the Alborán Sea

We explored the possible effects of the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) on interannual sea surface temperature (SST) variations in the Alborán Sea, both separately and combined. The probability of observing mean annual SST values higher than average was related to NAO and AO values of the previous year. The effect of NAO on SST was negative, while that of AO was positive. The pure effects of NAO and AO on SST are obscuring each other, due to the positive correlation between them. When decomposing SST, NAO and AO in seasonal values, we found that variation in mean annual SST and mean winter SST was significantly related to the mean autumn NAO of the previous year, while mean summer SST was related to mean autumn AO of the previous year. The one year delay in the effect of the NAO and AO on the SST could be partially related to the amount of accumulated snow, as we found a significant correlation between the total snow in the North Alborán watershed for a year with the annual average SST of the subsequent year. A positive AO implies a colder atmosphere in the Polar Regions, which could favour occasional cold waves over the Iberian Peninsula which, when coupled with precipitations favoured by a negative NAO, may result in snow precipitation. This snow may be accumulated in the high peaks and melt down in spring-summer of the following year, which consequently increases the runoff of freshwater to the sea, which in turn causes a diminution of sea surface salinity and density, and blocks the local upwelling of colder water, resulting in a higher SST.

Modelling Favourability for Invasive Species Encroachment to Identify Areas of Native Species Vulnerability

We assessed the vulnerability of the native Mediterranean pond turtle to encroachment by the invasive red-eared slider in southern Spain. We first obtained an ecogeographical favourability model for the Mediterranean pond turtle. We then modelled the presence/absence of the red-eared slider in the Mediterranean pond turtle range and obtained an encroachment favourability model. We also obtained a favourability model for the red-eared slider using the ecogeographical favourability for the Mediterranean pond turtle as a predictor. When favourability for the Mediterranean pond turtle was high, favourability for the red-eared slider was low, suggesting that in these areas the Mediterranean pond turtle may resist encroachment by the red-eared slider. We also calculated favourability overlap between the two species, which is their simultaneous favourability. Grids with low overlap had higher favourability values for the Mediterranean pond turtle and, consequently, were of lesser conservation concern. A few grids had high values for both species, being potentially suitable for coexistence. Grids with intermediate overlap had similar intermediate favourability values for both species and were therefore areas where the Mediterranean pond turtle was more vulnerable to encroachment by the red-eared slider. We mapped the favourability overlap to provide a map of vulnerability of the Mediterranean pond turtle to encroachment by the red-eared slider.

Phylogenetic analyses reveal that Schellackia parasites (Apicomplexa) detected in American lizards are closely related to the genus Lankesterella: is the range of Schellackia restricted to the Old World?

BackgroundSpecies of Schellackia Reichenow, 1919 have been described from the blood of reptiles distributed worldwide. Recently, Schellackia spp. detected in European and Asian lizards have been molecularly characterised. However, parasites detected in American lizard hosts remain uncharacterised. Thus, phylogenetic affinities between the Old and New World parasite species are unknown.MethodsIn the present study, we characterised morphologically and molecularly the hemococcidian parasites (sporozoites) that infect three lizard hosts from North America and two from South America.ResultsIn total, we generated 12 new 18S rRNA gene sequences of hemococcidian parasites infecting New World lizard hosts. By the microscopic examination of the smears we identified Schellackia golvani Rogier & Landau, 1975 (ex Anolis carolinensis Voigt) and Schellackia occidentalis Bonorris & Ball, 1955 (ex Uta stansburiana Baird & Girard and Sceloporus occidentalis Baird & Girard) in some samples, but the phylogenetic analysis indicated that all 18S rDNA sequences are distant from Schellackia species found in Old World lizards. In fact, the hemococcidian parasites detected in the New World lizards (including S. occidentalis and S. golvani) were closely related to the genus Lankesterella Labbé, 1899. Consequently, we suggest these two species to be included within the genus Lankesterella.ConclusionsLife history traits of hemococcidian parasites such as the type of host blood cells infected, host species or number of refractile bodies are not valid diagnostic characteristics to differentiate the parasites between the genera Schellackia and Lankesterella. Indeed, lankesterellid parasites with a different number of refractile bodies had a close phylogenetic origin. Based on the phylogenetic results we provide a systematic revision of the North American hemococcidians. Our recommendation is to include the species formerly described in the genus Schellackia that infect American lizards into Lankesterella (Lankesterellidae) as Lankesterella golvani (Rogier & Landau, 1975) n. comb and L. occidentalis (Bonorris & Ball, 1955) n. comb.

An updated phylogeny and morphological study of the Phymaturus vociferator clade (Iguania: Liolaemidae)

Species delimitation in Phymaturus has been a difficult task due to the highly conserved morphological and ecological features present in this genus. Almost all species of Phymaturus have been described without DNA data or lacking statistical analyses which makes even more difficult to compare species. Although two molecular phylogenetic studies have been recently published, here we provide the first multilocus phylogenetic reconstruction including all Chilean species, with samples from all type localities and some previously unsampled populations. We also estimate pairwise distances among the Chilean species of Phymaturus (P. vociferator and P. mallimaccii clades) and compare our results with the P. payuniae clade, where previous studies have used multiple lines of evidence. Additionally, we performed univariate and multivariate morphological analyses and skeletal comparisons (clavicle) for the species of the P. vociferator clade. As a result of this integrative approach, we describe a new species.

Liolaemus patriciaiturrae Navarro and Núñez, 1993 (Squamata: Liolaemidae): Distribution extension in northern Chile and geographic distribution map

We report two new records for Liolaemus patriciaiturrae in Chile, one corresponding to specimens previously misidentified as L. nigriceps. We also provide a map showing all the known locations of the species.

commentary: Hot research on roasted lizards: warming, evolution and extinction in climate change studies

news and update Putterman, L. (2008). Agriculture, diffusion and devel- opment: Ripple effects of the Neolithic Revolu- tion. Economica, 75, 729-748. Smith, A. (1776). An Inquiry into the Nature and Causes of the Wealth of Nations. Reprinted in 1976. University of Chicago Press, Chicago. William R. Burnside University of New Mexico, Albuquerque, NM, USA e-mail: burnsidewr@gmail.com http://biology.unm.edu/jhbrown/ labmembers.shtml Edited by Joaquin Hortal commentary Hot research on roasted lizards: warming, evolution and extinc- tion in climate change studies In volume 328 of Science, a team headed by Barry Sinervo published a study forecasting the effect of increased temperature in lizards. They demon- strate that climate change has already caused ex- tinctions of lizard populations worldwide. They also forecast that if climate change scenarios come true, 40% of all lizard populations and 20% of all species could be committed to extinction by 2080. Predictions are supported by a model that represents how much activity time will be re- stricted (i.e., hours of restriction; hr) because op- erative temperatures are too high. The study uses a multidisciplinary approach incorporating ecophysiology, evolutionary biology, biogeography and phylogenetics. A special strength of the study is that it uses models that are validated with data from recent population extinctions, which is an extremely rare feature in studies assessing climate change effects on biodi- versity (but see Araujo et al. 2005). Sinervo et al.’s study links temperature increases to the organis- mal biology of the lizards making it possible to predict local extinctions. Unfortunately, such a link leads to a worrisome message: “Climate- forced reptile extinctions are happening now” (Huey et al. 2010). Forecasts of species extinctions due to cli- mate change are typically based on assessments of changes in climatic suitability for species (e.g. Thomas et al. 2004; Thuiller et al. 2005). Sinervo and colleagues go beyond this climate envelope approach and incorporate aspects of the ecology and behavior that are thought to mediate the re- sponses of species to climate change. The incorpo- ration of ecological and behavioral mechanisms into models attempting to provide insight of the likely responses of species to climate change is welcomed (Brook et al. 2009), but when such at- tempts involve large numbers of species and bio- geographical scales compromises between preci- sion and generality are inevitable. One of such compromises is related to the use of estimated operative temperatures (the equilibrium temperature of a lizard with its ther- mal environment) in the study. Operative tem- peratures can vary greatly due to micro- environmental heterogeneity (Bauwens et al., 1996). Lizards may select locations with cooler micro-climates instead of moving higher in alti- tude or latitude. Open habitat species for exam- ple, may encroach into forests (Huey et al. 2009). This study would have benefited from integrating small scale thermal heterogeneity into large scale studies, although precisely how this can be ac- complished remains a key challenge for mechanis- tically motivated models of climate change. Investigators such as Kearney et al. (2008) and Mitchell et al. (2008) have created biophysical models of the thermal environment of reptiles to make predictions on the effect of global warming on individual species. These models use heat and energy balance equations to relate environmental conditions with ecophysiological traits measured in the laboratory. These relationships can be mapped geographically to evaluate climate suit- ability for the species of interest. Sinervo et al. frontiers of biogeography 2.3, 2010 —