- Department of Biology
Petit Science Center
Georgia State University
Atlanta, GA 30303
Frank R Castelli
Georgia State University, Deparment of Biology, Faculty Member
Research Interests:
Enrollment in courses taught remotely in higher education has been on the rise, with a recent surge in response to a global pandemic. While adapting this form of teaching, instructors familiar with traditional face-to-face methods are now... more
Enrollment in courses taught remotely in higher education has been on the rise, with a recent surge in response to a global pandemic. While adapting this form of teaching, instructors familiar with traditional face-to-face methods are now met with a new set of challenges, including students not turning on their cameras during synchronous class meetings held via videoconferencing. After transitioning to emergency remote instruction in response to the COVID-19 pandemic, our introductory biology course shifted all in-person laboratory sections into synchronous class meetings held via the Zoom videoconferencing program. Out of consideration for students, we established a policy that video camera use during class was optional, but encouraged. However, by the end of the semester, several of our instructors and students reported lower than desired camera use that diminished the educational experience. We surveyed students to better understand why they did not turn on their cameras. We confirmed several predicted reasons including the most frequently reported: being concerned about personal appearance. Other reasons included being concerned about other people and the physical location being seen in the background and having a weak in-ternet connection, all of which our exploratory analyses suggest may disproportionately influence underrepresented minorities. Additionally, some students revealed to us that social norms also play a role in camera use. This information was used to develop strategies to encourage-without requiring-camera use while promoting equity and inclusion. Broadly, these strategies are to not require camera use, explicitly encourage usage while establishing norms, address potential distractions, engage students with active learning, and understand your students' challenges through surveys. While the demographics and needs of students vary by course and institution, our recommendations will likely be directly helpful to many instructors and also serve as a model for gathering data to develop strategies more tailored for other student populations.
Research Interests:
Biology laboratory courses with hands-on activities faced many challenges when switched to online instruction during the COVID-19 pandemic. The transition back to in-person instruction presents an opportunity to redesign courses with... more
Biology laboratory courses with hands-on activities faced many challenges when switched to online instruction during the COVID-19 pandemic. The transition back to in-person instruction presents an opportunity to redesign courses with greater student input. Undergraduates in an ∼350-student laboratory course were surveyed about their preferences for online or in-person instruction of specific laboratory course components. We predicted that students who have taken a virtual laboratory course prefer keeping some of the components online. We also hypothesized that their preferences are affected by their experience with online-only or with both online and in-person instruction. The results showed that students would like to move the laboratory component and group meetings back to in-person instruction, even if they never experienced college-level in-person courses. Also, many components, including the lectures, exams, assignment submission, and office hours are preferred to be held online. Surprisingly, students who have only taken online courses would rather give group presentations in person, while those who experienced both online and in-person instruction were undecided. Group presentations were the only component where the preference of the two groups significantly differed. Self-assessed learning gains showed that students performed very well in both the online semesters and the in-person semesters. Therefore, the preferences measured in this study were likely developed based on students’ future expectations and personal gains, and not only on their metacognitive decisions and academic performances. This study provides considerations for redesigning components of laboratory courses to be more student-centered after the pandemic.
Research Interests:
Speciation provides a framework for classifying biodiversity on Earth and is a central concept in evolutionary biology. To help undergraduate students learn about speciation, we designed a student-centered lesson that uses active-learning... more
Speciation provides a framework for classifying biodiversity on Earth and is a central concept in evolutionary biology. To help undergraduate students learn about speciation, we designed a student-centered lesson that uses active-learning techniques (e.g., clicker questions, small group work, and whole class discussion) and compares multiple species concepts (morphological, biological, and phylogenetic) using giraffes as an example. Giraffes were chosen as the focus of this lesson because they are familiar and have broad appeal to students; are in danger of becoming extinct; and have ecological, economic, and cultural importance. Students also learn about contemporary giraffe conservation issues and the current debate in the literature regarding the total number of giraffe species. Students then apply their knowledge by working in small groups on speciation scenarios that highlight organisms across the tree of life. Student understanding is assessed using multiple-choice pre/post-test questions, in-class clicker questions with peer discussion, and exam questions. Here we provide details about the lesson and report that student learning is improved.
Research Interests:
Speciation provides a framework for classifying biodiversity on Earth and is a central concept in evolutionary biology. To help undergraduate students learn about speciation, we designed a student-centered lesson that uses active-learning... more
Speciation provides a framework for classifying biodiversity on Earth and is a central concept in evolutionary biology. To help undergraduate students learn about speciation, we designed a student-centered lesson that uses active-learning techniques (e.g., clicker questions, small group work, and whole class discussion) and compares multiple species concepts (morphological, biological, and phylogenetic) using giraffes as an example. Giraffes were chosen as the focus of this lesson because they are familiar and have broad appeal to students; are in danger of becoming extinct; and have ecological, economic, and cultural importance. Students also learn about contemporary giraffe conservation issues and the current debate in the literature regarding the total number of giraffe species. Students then apply their knowledge by working in small groups on speciation scenarios that highlight organisms across the tree of life. Student understanding is assessed using multiple-choice pre/post-test questions, in-class clicker questions with peer discussion, and exam questions. Here we provide details about the lesson and report that student learning is improved.
Research Interests:
Territoriality is an adaptive behavioral trait that is important for animal's fitness and there still remains much to learn about the proximate mechanisms underlying the development of territoriality. We speculate that the formation... more
Territoriality is an adaptive behavioral trait that is important for animal's fitness and there still remains much to learn about the proximate mechanisms underlying the development of territoriality. We speculate that the formation of a conditioned place preference (CPP), an increased time allocation to the environment where a rewarding experience occurred, contributes to territoriality. Testosterone (T) plays an important role in modulating territorial behaviors and T pulses can induce a CPP. We confirmed previous findings in California mice (Peromyscus californicus) that T pulses can induce a CPP in singly-housed, but not group-housed males. Housing singly may be similar enough to dispersal in nature to initiate similar hormonal and neuroanatomical changes needed for the development of territoriality. We further revealed that T pulses interact with the single housing experience and appear to enhance the motivation to be aggressive towards a stimulus male. On a neural level, being singly housed upregulated levels of androgen receptors in the preoptic area, which positively correlated with the strength of the CPP. We speculate that this change in androgen sensitivity in the preoptic area is characteristic of males that have dispersed, making them more sensitive to T pulses. Also, single housing increased markers of synaptic plasticity in the nucleus accumbens, ventral and dorsal hippocampus, neural changes that may be associated with dispersal, reproduction and territory establishment. These behavioral and neural changes may reflect the life history transition from residing in the natal territory to dispersing and establishing a new territory.
Research Interests: Neuroscience, Animal Behavior, Biology, Medicine, Nucleus Accumbens, and 15 moreBiological Sciences, Behavioral Neuroendocrinology, Hippocampus, Rodents, Androgens, Social and Behavioral Sciences, Hormones and Behavior, Synapsin, Hormones and Behaviour, Peromyscus, Androgen Receptor, Academic, Conditioned place preference, California mice, and Medical and Health Sciences
Species comparisons indicate that scent-marking may differ as a function of mating system and co-housing with the opposite sex ("pairing"). We previously demonstrated that pairing may decrease male solicitation to unfamiliar... more
Species comparisons indicate that scent-marking may differ as a function of mating system and co-housing with the opposite sex ("pairing"). We previously demonstrated that pairing may decrease male solicitation to unfamiliar females in the monogamous Peromyscus californicus but not in the non-monogamous P. leucopus. Whether urine scent-marking of females changes following pairing and whether scent-marking of paired males varies in response to scent-marks of their cagemate versus those of an unfamiliar female has not been examined. Therefore, we tested P. californicus and P. leucopus for within and between species differences in urine scent-marking of: 1) paired and non-paired females in an unscented arena, and 2) paired males in response to their female cagemate's or an unfamiliar female's scent-marks (counter-marking). Consistent with previous findings, P. californicus of both sexes deposited more urine scent-marks and covered greater surface area than P. leucopus...
Research Interests:
Species comparisons indicate that scent-marking may differ as a function of mating system and co-housing with the opposite sex (“pairing”). We previously demonstrated that pairing may decrease male solicitation to unfamiliar females in... more
Species comparisons indicate that scent-marking may differ as a function of mating system and co-housing with the opposite sex (“pairing”). We previously demonstrated that pairing may decrease male solicitation to unfamiliar females in the monogamous Peromyscus californicus but not in the non-monogamous P. leucopus. Whether urine scent-marking of females changes following pairing and whether scent-marking of paired males varies in response to scent-marks of their cagemate versus those of an unfamiliar female has not been examined. Therefore, we tested P. californicus and P. leucopus for within and between species differences in urine scent-marking of: 1) paired and non-paired females in an unscented arena, and 2) paired males in response to their female cagemate’s or an unfamiliar female’s scent-marks (counter-marking). Consistent with previous findings, P. californicus of both sexes deposited more urine scent-marks and covered greater surface area than P. leucopus. In both species, female scent-marking did not differ according to pairing status and male counter-marking did not differ in response to the scent-marks of their female cagemate versus an unfamiliar female. More females of both species and more P. leucopus, but not P. californicus, males scent-marked more around the perimeter than centrally. Potential explanations for these findings are discussed.
Research Interests:
Research Interests:
In socially monogamous mammals, male behaviour can have important consequences on production and survival of offspring. Therefore, females in these species could enhance their reproductive success by discriminating among potential male... more
In socially monogamous mammals, male behaviour can have important consequences on production and survival of offspring. Therefore, females in these species could enhance their reproductive success by discriminating among potential male social partners and mates on the basis of phenotypic cues correlated with male fidelity and paternal behaviour. Prairie voles, Microtus ochrogaster, are socially monogamous rodents that typically form pair bonds and show extensive biparental care. In male prairie voles, variation in the length of microsatellite DNA in the regulatory region of the avpr1a gene encoding the vasopressin 1a receptor (V1aR) underlies differences in V1aR neural expression and is correlated with significant differences in partner preference and paternal behaviour. Previous laboratory studies demonstrated that males possessing longer avpr1a microsatellite alleles spend more time with their female social partner, sire offspring with fewer females and provide more paternal care relative to males with shorter avpr1a microsatellite alleles. Our results from laboratory preference trials showed that female voles from populations in Illinois and Kansas displayed significant social and sexual preferences for males that possessed longer avpr1a microsatellite alleles. These findings are consistent with the hypothesis that females are using phenotypic cues whose expression is correlated with a male’s avpr1a microsatellite genotype to discriminate among potential mates. These social and sexual preferences for males with longer avpr1a microsatellite alleles may result in increased female reproductive success.
Research Interests:
Intraspecific variation in sociosexual behavior has typically been investigated in the context of its relationship with environmental factors, but neurogenetic factors can also influence sociosexual behavior. In laboratory studies of... more
Intraspecific variation in sociosexual behavior has typically been investigated in the context of its relationship with environmental factors, but neurogenetic factors can also influence sociosexual behavior. In laboratory studies of prairie voles (Microtus ochrogaster), length polymorphism of microsatellite DNA within the gene (avpr1a) encoding the vasopressin 1a receptor is correlated with variation in male sociosexual behavior. However, field studies of prairie voles have found the relationship between male avpr1a microsatellite allele length and sociosexual behavior to be more ambiguous, possibly because most males had alleles of intermediate length. We tested the hypothesis that avpr1a microsatellite allele length mediates male sociosexual behavior in field settings by releasing voles into field enclosures where every male possessed two avpr1a microsatellite alleles at least one standard error longer or shorter than the mean length in their population of origin. Voles from an Illinois and Kansas population were examined separately as social monogamy appears more prevalent in the Illinois population. Illinois males with long avpr1a microsatellite alleles had smaller home ranges and overlapped a greater proportion of the home range of the female that they overlapped the most. Kansas males showed the opposite pattern. Illinois, but not Kansas, males with long avpr1a microsatellite alleles sired offspring with more females and sired more litters. Our results support the hypothesis that genetic variation associated with the avpr1a gene plays a role in mediating male prairie vole sociosexual behavior in nature. However, the relationship between specific male behaviors and male avpr1a microsatellite allele length sometimes differed significantly between Kansas and Illinois voles, suggesting relationships between specific male sociosexual behaviors and polymorphism associated with the avpr1a locus are complex, possibly involving specific nucleotide sequences or other population‐specific genetic differences.
Research Interests:
Intraspecific variation in sociosexual behavior has typically been investigated in the context of its relationship with environmental factors, but neurogenetic factors can also influence sociosexual behavior. In laboratory studies of... more
Intraspecific variation in sociosexual behavior has typically been investigated in the context of its relationship with environmental factors, but neurogenetic factors can also influence sociosexual behavior. In laboratory studies of prairie voles (Microtus ochrogaster), length polymorphism of microsatellite DNA within the gene (avpr1a) encoding the vasopressin 1a receptor is correlated with variation in male sociosexual behavior. However, field studies of prairie voles have found the relationship between male avpr1a microsatellite allele length and sociosexual behavior to be more ambiguous, possibly because most males had alleles of intermediate length. We tested the hypothesis that avpr1a microsatellite allele length mediates male sociosexual behavior in field settings by releasing voles into field enclosures where every male possessed two avpr1a microsatellite alleles at least one standard error longer or shorter than the mean length in their population of origin. Voles from an Illinois and Kansas population were examined separately as social monogamy appears more prevalent in the Illinois population. Illinois males with long avpr1a microsatellite alleles had smaller home ranges and overlapped a greater proportion of the home range of the female that they overlapped the most. Kansas males showed the opposite pattern. Illinois, but not Kansas, males with long avpr1a microsatellite alleles sired offspring with more females and sired more litters. Our results support the hypothesis that genetic variation associated with the avpr1a gene plays a role in mediating male prairie vole sociosexual behavior in nature. However, the relationship between specific male behaviors and male avpr1a microsatellite allele length sometimes differed significantly between Kansas and Illinois voles, suggesting relationships between specific male sociosexual behaviors and polymorphism associated with the avpr1a locus are complex, possibly involving specific nucleotide sequences or other population-specific genetic differences.
Research Interests:
ABSTRACT Pair-bonded males often make substantial contributions to the care of their offspring. Male parental behavior may be affected by a range of factors, including previous experience (parental or alloparental), genetic influences,... more
ABSTRACT Pair-bonded males often make substantial contributions to the care of their offspring. Male parental behavior may be affected by a range of factors, including previous experience (parental or alloparental), genetic influences, and contributions by the female partner. Previous studies have shown that a microsatellite polymorphism in the regulatory region of the avpr1a gene influences aspects of paternal behavior in male prairie voles (Microtus ochrogaster). Specifically, males with longer avpr1a microsatellites groomed offspring more than did males with shorter avpr1a microsatellites. Previous experience with alloparental care also appears to influence subsequent paternal care in prairie voles. We investigated the influence of avpr1a microsatellite length and previous parental experience on paternal behavior in prairie voles two generations from the field and specially bred to exaggerate differences in avpr1a microsatellite length. We found that avpr1a microsatellite length alone did not affect any of the paternal behaviors that we measured. In contrast, males differed in parental behavior between first and second litters. Regardless of avpr1a microsatellite length, males licked/groomed the second litter less, and retrieved pups more quickly during the second compared to the first litter. Our results show that previous paternal experience may play a more important role than the length of the microsatellite in the regulatory region of the avpr1a gene in influencing paternal care.
Research Interests:
Pair-bonded males often make substantial contributions to the care of their offspring. Male parental behavior may be affected by a range of factors, including previous experience (parental or alloparental), genetic influences, and... more
Pair-bonded males often make substantial contributions to the care of their offspring. Male parental behavior may be affected by a range of factors, including previous experience (parental or alloparental), genetic influences, and contributions by the female partner. Previous studies have shown that a microsatellite polymorphism in the regulatory region of the avpr1a gene influences aspects of paternal behavior in male prairie voles (Microtus ochrogaster). Specifically, males with longer avpr1a microsatellites groomed offspring more than did males with shorter avpr1a microsatellites. Previous experience with alloparental care also appears to influence subsequent paternal care in prairie voles. We investigated the influence of avpr1a microsatellite length and previous parental experience on paternal behavior in prairie voles two generations from the field and specially bred to exaggerate differences in avpr1a microsatellite length. We found that avpr1a microsatellite length alone did not affect any of the paternal behaviors that we measured. In contrast, males differed in parental behavior between first and second litters. Regardless of avpr1a microsatellite length, males licked/groomed the second litter less, and retrieved pups more quickly during the second compared to the first litter. Our results show that previous paternal experience may play a more important role than the length of the microsatellite in the regulatory region of the avpr1a gene in influencing paternal care.