Echolocation is the primary sense used by most bats to navigate their environment. However, the i... more Echolocation is the primary sense used by most bats to navigate their environment. However, the influence of echolocating behaviors upon the morphology of the auditory apparatus remains largely uninvestigated. While it is known that middle ear ossicle size scales positively with body mass across mammals, and that peak call frequency scales negatively with body mass among bats, there are still large gaps in our understanding of the degree to which allometry or ecology influences the morphology of the chiropteran auditory apparatus. To investigate this, we used μCT datasets to quantify three morphological components of the inner and middle ear: ossicle size, ossicle shape, and cochlear spirality. These data were collected across 27 phyllostomid species, spanning a broad range of body sizes, habitats, and dietary categories, and the relationships between these variables and ear morphology were assessed using a comparative phylogenetic approach. Ossicle size consistently scaled with str...
Previously, our lab has studied the scaling and dietary correlates of masticatory muscle fiber ar... more Previously, our lab has studied the scaling and dietary correlates of masticatory muscle fiber architecture separately in felids, musteloids, canids, and ursids as well as across the carnivoran order as a whole. In some of these lineages, fascicle lengths (FLs; a correlate of gape) scale with relative diet size, while across the order and divisions thereof, correlates of bite force (muscle mass and physiological cross‐sectional area; PCSA) predominantly scale with body size. In a subsequent recent analysis of 40 taxa spanning eight families from this broader sample, we found that volumetric estimators (e.g., the commonly used “dry‐skull” method described by Thomason) can be used to closely estimate muscle mass and PCSA from osteological remains alone. In the current investigation, we are using the same sample to evaluate osteological correlates of dissection‐based FL measurements. In a preliminary analysis of 14 musteloid taxa representing mustelids, mephitids, and procyonids, chosen because musteloid FL correlated best with diet size, we measured 13 origin to insertion distances to compare to the FLs of the masticatory adductors of these taxa. Raw individual and combined osteological distances were then regressed against FL for each individual muscle as well as average adductor FL using RMA regression. Residuals of same variables relative to body mass and cranial size were also compared. The most highly correlated raw osteological measurement for each muscle resulted in r2 values of 0.92‐0.65 for the best correlate of each adductor individually and their combination. However, correlations dropped substantially (r2=0.69‐0.29 for temporalis, masseter, and all adductors combined) when body size was accounted for, and the medial pterygoid osteological FL proxies accounted for almost none of the variation in measured FL (r2=0.08 for its highest proxy). Although the temporalis is the largest mandibular adductor, the best osteological proxies for relative FL were found for the masseter muscles (r2=0.69 vs. r2=0.29 for temporalis) – perhaps because the temporalis origin is affected by the neuro‐protective and sensory functions of the cranium, while the origin to insertion region of the masseter is almost entirely influenced by masticatory function. Combining these findings with measures of jaw leverage, it is possible to reconstruct not only FL in fossil musteloids but also gape – a method that may give new insight into relative diet sizes consumed by these taxa. Expanding our methods across the other members of the order will allow for the theoretical ex vivoapproximation of gape in modern taxa for which in vivo data have not been systematically collected and also myological approaches to gape estimation in extinct taxa like Smilodon and other sabertooths.
The advantages of active learning strategies in the college science classroom have been noted rep... more The advantages of active learning strategies in the college science classroom have been noted repeatedly throughout recent literature (Freeman et al. Proc Natl Acad Sci 111(23):8410–8415, 2014). However, the introduction of such lessons in a postsecondary environment is typically met with a number of unique challenges such as large class size and atypical classroom dynamics. The recent advances and acceptance of augmented reality as a teaching tool opens up a vast new world in the realm of science instruction. The classroom implementation of augmented applications firmly grounded in both learning and cognitive theories provide college science instructors a new and exciting way to engross their students in the scientific world. Here we outline the advantages of using augmented reality applications in the science classroom to promote active learning and student engagement. Additionally, we provide topic-specific examples and suggestions for lesson strategies so that readers may take advantage of the ever-evolving multimedia technology in the classroom.
Echolocation is the primary sense used by most bats to navigate their environment. However, the i... more Echolocation is the primary sense used by most bats to navigate their environment. However, the influence of echolocating behaviors upon the morphology of the auditory apparatus remains largely uninvestigated. While it is known that middle ear ossicle size scales positively with body mass across mammals, and that peak call frequency scales negatively with body mass among bats, there are still large gaps in our understanding of the degree to which allometry or ecology influences the morphology of the chiropteran auditory apparatus. To investigate this, we used μCT datasets to quantify three morphological components of the inner and middle ear: ossicle size, ossicle shape, and cochlear spirality. These data were collected across 27 phyllostomid species, spanning a broad range of body sizes, habitats, and dietary categories, and the relationships between these variables and ear morphology were assessed using a comparative phylogenetic approach. Ossicle size consistently scaled with str...
Previously, our lab has studied the scaling and dietary correlates of masticatory muscle fiber ar... more Previously, our lab has studied the scaling and dietary correlates of masticatory muscle fiber architecture separately in felids, musteloids, canids, and ursids as well as across the carnivoran order as a whole. In some of these lineages, fascicle lengths (FLs; a correlate of gape) scale with relative diet size, while across the order and divisions thereof, correlates of bite force (muscle mass and physiological cross‐sectional area; PCSA) predominantly scale with body size. In a subsequent recent analysis of 40 taxa spanning eight families from this broader sample, we found that volumetric estimators (e.g., the commonly used “dry‐skull” method described by Thomason) can be used to closely estimate muscle mass and PCSA from osteological remains alone. In the current investigation, we are using the same sample to evaluate osteological correlates of dissection‐based FL measurements. In a preliminary analysis of 14 musteloid taxa representing mustelids, mephitids, and procyonids, chosen because musteloid FL correlated best with diet size, we measured 13 origin to insertion distances to compare to the FLs of the masticatory adductors of these taxa. Raw individual and combined osteological distances were then regressed against FL for each individual muscle as well as average adductor FL using RMA regression. Residuals of same variables relative to body mass and cranial size were also compared. The most highly correlated raw osteological measurement for each muscle resulted in r2 values of 0.92‐0.65 for the best correlate of each adductor individually and their combination. However, correlations dropped substantially (r2=0.69‐0.29 for temporalis, masseter, and all adductors combined) when body size was accounted for, and the medial pterygoid osteological FL proxies accounted for almost none of the variation in measured FL (r2=0.08 for its highest proxy). Although the temporalis is the largest mandibular adductor, the best osteological proxies for relative FL were found for the masseter muscles (r2=0.69 vs. r2=0.29 for temporalis) – perhaps because the temporalis origin is affected by the neuro‐protective and sensory functions of the cranium, while the origin to insertion region of the masseter is almost entirely influenced by masticatory function. Combining these findings with measures of jaw leverage, it is possible to reconstruct not only FL in fossil musteloids but also gape – a method that may give new insight into relative diet sizes consumed by these taxa. Expanding our methods across the other members of the order will allow for the theoretical ex vivoapproximation of gape in modern taxa for which in vivo data have not been systematically collected and also myological approaches to gape estimation in extinct taxa like Smilodon and other sabertooths.
The advantages of active learning strategies in the college science classroom have been noted rep... more The advantages of active learning strategies in the college science classroom have been noted repeatedly throughout recent literature (Freeman et al. Proc Natl Acad Sci 111(23):8410–8415, 2014). However, the introduction of such lessons in a postsecondary environment is typically met with a number of unique challenges such as large class size and atypical classroom dynamics. The recent advances and acceptance of augmented reality as a teaching tool opens up a vast new world in the realm of science instruction. The classroom implementation of augmented applications firmly grounded in both learning and cognitive theories provide college science instructors a new and exciting way to engross their students in the scientific world. Here we outline the advantages of using augmented reality applications in the science classroom to promote active learning and student engagement. Additionally, we provide topic-specific examples and suggestions for lesson strategies so that readers may take advantage of the ever-evolving multimedia technology in the classroom.
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