scholarly journals Geographic variation in the skulls of the horseshoe bats, Rhinolophus simulator and R. cf. simulator : Determining the relative contributions of adaptation and drift using geometric morphometrics

2021 ◽  
Author(s):  
Gregory L. Mutumi ◽  
David S. Jacobs ◽  
Lunga Bam
Keyword(s):  
Geometric Morphometrics ◽  
Geographic Variation ◽  
Horseshoe Bats

scholarly journals Ambient temperature correlates with geographic variation in body size of least horseshoe bats

2020 ◽  
Vol 66 (5) ◽  
pp. 459-465 ◽  
Author(s):  
Man Wang ◽  
Kelly Chen ◽  
Dongge Guo ◽  
Bo Luo ◽  
Weiwei Wang ◽  
...  
Keyword(s):  
Body Size ◽  
Geographic Variation ◽  
Body Mass ◽  
Body Length ◽  
Primary Productivity ◽  
Minimum Temperature ◽  
Maximum Temperature ◽  
Heat Conservation ◽  
The Mean ◽  
Horseshoe Bats

Abstract Geographic variation in body size is common within many animal species. The causes of this pattern, however, remain largely unexplored in most vertebrate groups. Bats are widely distributed globally owing to their ability of powered flight. Most bat species encounter a variety of climatic conditions across their distribution range, making them an ideal taxon for the study of ecogeographic patterns in body size. Here, we used adult least horseshoe bats, Rhinolophus pusillus, to test whether geographic variation in body size was determined by heat conservation, heat dissipation, climatic seasonality, or primary productivity. We measured body mass and head-body length for 246 adult bats from 12 allopatric colonies in China. We quantified the ecological conditions inhabited by each colony, including mean maximum temperature of the warmest month, mean minimum temperature of the coldest month, temperature seasonality, precipitation seasonality, and annual net primary productivity (ANPP). Body mass and head-body length, 2 of the most reliable indicators of body size, exhibited marked differences between colonies. After controlling for spatial autocorrelation, the mean minimum temperature of the coldest month explained most of the variation in body size among colonies, regardless of sex. The mean maximum temperature, climatic seasonality, and ANPP had limited power in predicting body size of males or females in comparison with mean minimum temperature. These results support the heat conservation hypothesis and suggest adaptive responses of body size to cold climates in cave-dwelling bats.

scholarly journals Size and shape variability in the skull of Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae) from two geographic areas in Brazil

2008 ◽  
Vol 68 (3) ◽  
pp. 623-631 ◽  
Author(s):  
R. Bornholdt ◽  
LR. Oliveira ◽  
ME. Fabián
Keyword(s):  
Sexual Dimorphism ◽  
Geometric Morphometrics ◽  
Geographic Variation ◽  
Ecological Factors ◽  
Lateral View ◽  
Centroid Size ◽  
Skull Shape ◽  
Size And Shape ◽  
The Brain ◽  
South Brazil

We present a quantitative analysis of sexual dimorphism and geographic variation in the skull of Myotis nigricans (Schinz, 1821) assessed by geometric morphometrics. Differences in size and shape of skulls were investigated using 30 landmarks plotted on two-dimensional images of lateral and ventral views. Results of geometric morphometrics revealed sexual dimorphism in the centroid size of the skull in both views. Females were larger than males. Nevertheless, there was no sexual dimorphism in skull shape of M. nigricans. Geographic variation was detected in size and shape of the skull. South Brazilian specimens were significantly larger than Ceará specimens only in the lateral view. Differences in skull shape were statistically significant in both views: specimens from South Brazil were brevirostri and presented a more expanded skull in the posterior region while Ceará specimens were longirostri and do not present any expansion in the brain case. Ecological factors for these phenomena are discussed in the text.

scholarly journals Geographic Variation in the Acoustic Traits of Greater Horseshoe Bats: Testing the Importance of Drift and Ecological Selection in Evolutionary Processes

PLoS ONE ◽  
2013 ◽  
Vol 8 (8) ◽  
pp. e70368 ◽  
Author(s):  
Keping Sun ◽  
Li Luo ◽  
Rebecca T. Kimball ◽  
Xuewen Wei ◽  
Longru Jin ◽  
...  
Keyword(s):  
Geographic Variation ◽  
Evolutionary Processes ◽  
Ecological Selection ◽  
Horseshoe Bats

scholarly journals Geographic variation in the skulls of the horseshoe bats, Rhinolophus simulator and R. cf. simulator: determining the relative contributions of adaptation and drift using geometric morphometrics.

2020 ◽  
Author(s):  
Gregory Mutumi ◽  
David Jacobs ◽  
Lunga Bam
Keyword(s):  
Geometric Morphometrics ◽  
Selection Pressure ◽  
Test Cases ◽  
Shape Variation ◽  
Population Variance ◽  
Phenotypic Characters ◽  
Optimal Functioning ◽  
Selective Forces ◽  
Horseshoe Bat ◽  
Horseshoe Bats

The relative contributions of adaptation and drift to morphological diversification of the crania of echolocating mammals was investigated using two horseshoe bat species, Rhinolophus simulator and R. cf. simulator as test cases. We used 3D geometric morphometrics to compare the shapes of skulls of the two lineages collected at various localities in southern Africa. Shape variation was predominantly attributed to selective forces; the between population variance (B) was not proportional to the within population variance (W). Modularity was evident in the crania of R. simulator but absent in the crania of R. cf. simulator and the mandibles of both species. The skulls of the two lineages thus appeared to be under different selection pressures, despite the overlap in their distributions. Selection acted mainly on the nasal dome region of R. cf. simulator whereas selection acted more on the cranium and mandibles than on the nasal domes of R. simulator. Probably the relatively higher echolocation frequencies used by R. cf. simulator, the shape of the nasal dome, which acts as a frequency dependent acoustic horn, is more crucial than in R. simulator, allowing maximization of the intensity of the emitted calls and resulting in comparable detection distances. In contrast, selection pressure is probably more pronounced on the mandibles and cranium of R. simulator to compensate for the loss in bite force because of its elongated rostrum. The predominance of selection probably reflects the stringent association between environment and the optimal functioning of phenotypic characters associated with echolocation and feeding in bats.

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