Intraspecific Variation in Maximum Ingested Food Size and Body Mass in Varecia rubra and Propithecus coquereli

In a recent study, we quantified the scaling of ingested food size (Vb)—the maximum size at which an animal consistently ingests food whole—and found that Vb scaled isometrically between species of captive strepsirrhines. The current study examines the relationship between Vb and body size within species with a focus on the frugivorous Varecia rubra and the folivorous Propithecus coquereli. We found no overlap in Vb between the species (all V. rubra ingested larger pieces of food relative to those eaten by P. coquereli), and least-squares regression of Vb and three different measures of body mass showed no scaling relationship within each species. We believe that this lack of relationship results from the relatively narrow intraspecific body size variation and seemingly patternless individual variation in Vb within species and take this study as further evidence that general scaling questions are best examined interspecifically rather than intraspecifically

The Jaw Adductor Resultant and Estimated Bite Force in Primates

We reconstructed the jaw adductor resultant in 34 primate species using new data on muscle physiological cross-sectional area (PCSA) and data on skull landmarks. Based on predictions by Greaves, the resultant should (1) cross the jaw at 30% of its length, (2) lie directly posterior to the last molar, and (3) incline more anteriorly in primates that need not resist large anteriorly-directed forces. We found that the resultant lies significantly posterior to its predicted location, is significantly posterior to the last molar, and is significantly more anteriorly inclined in folivores than in frugivores. Perhaps primates emphasize avoiding temporomandibular joint distraction and/or wide gapes at the expense of bite force. Our exploration of trends in the data revealed that estimated bite force varies with body mass (but not diet) and is significantly greater in strepsirrhines than in anthropoids. This might be related to greater contribution from the balancing-side jaw adductors in anthropoids

A sabre-tooth felid from Coopers Cave (Gauteng, South Africa) and its implications for Megantereon (Felidae: Machairodontinae) taxonomy

Metrical and morphological analysis of a new sabre-tooth felid mandible recovered from the Plio-Pleistocene hominid-bearing site of Coopers, South Africa, indicates that it can be assigned to the genus Megantereon, though it is by some measures the smallest individual of this taxon yet described. Comparison of morphological variability within this genus to that found within four extant, medium-sized felid species (Acinonyx jubatus, Neofelis nebulosa, Panthera pardus and P. uncia) and the extinct genus Smilodon (sister taxon of Megantereon) provides confirmation of the suggestion by Martínez-Navarro&Palmqvist (1995, 1996) that Megantereon is a geographically polymorphic genus comprised of at least two species: M. cultridens (Cuvier, 1824) of North America and Europe and M. whitei (Broom, 1937) of Africa and Europe.Duke University’s Undergraduate Research Support Office, Howard Hughes Program and Department of Biological Anthropology and Anatomy; the Palaeo-Anthropology Scientific Trust (PAST); the National Geographic Society; and the Wenner-Gren Foundation (grant 6914 to D.J.D.

STEM gender stereotypes from early childhood through adolescence at informal science centers.

Stereotypes about science, technology, engineering and mathematics (STEM) are associated with reduced STEM engagement amongst girls and women. The present study examined these stereotypes from early childhood through adolescence within informal science learning sites (ISLS; science museums, zoos, aquariums). Further, the study explored whether interactions with male or female educators influenced STEM stereotypes. Participants (n = 997, female = 572) were ISLS visitors in the UK and USA who either interacted with an educator, or no educator. With age participants were more likely to report that "both boys and girls" are "usually", "should" be, and "can" be good at STEM. Independent of age, male participants reported that their own gender group "should" be good at STEM. Educator interactions did not influence stereotype responses. These results highlight early childhood as a key developmental window in which to challenge ideas about who can and should be proficient in STEM

Assessing adolescents' critical health literacy: How is trust in government leadership associated with knowledge of COVID-19?

This study explored relations between COVID-19 news source, trust in COVID-19 information source, and COVID-19 health literacy in 194 STEM-oriented adolescents and young adults from the US and the UK. Analyses suggest that adolescents use both traditional news (e.g., TV or newspapers) and social media news to acquire information about COVID-19 and have average levels of COVID-19 health literacy. Hierarchical linear regression analyses suggest that the association between traditional news media and COVID-19 health literacy depends on participants' level of trust in their government leader. For youth in both the US and the UK who used traditional media for information about COVID-19 and who have higher trust in their respective government leader (i.e., former US President Donald Trump and UK Prime Minister Boris Johnson) had lower COVID-19 health literacy. Results highlight how youth are learning about the pandemic and the importance of not only considering their information source, but also their levels of trust in their government leaders

Learning hand in hand: Engaging in research-practice partnerships to advance developmental science.

Developmental science research often involves research questions developed by academic teams, which are tested within community or educational settings. In this piece, we outline the importance of research-practice partnerships, which involve both research and practice-based partners collaborating at each stage of the research process. We articulate challenges and benefits of these partnerships for developmental science research, identify relevant research frameworks that may inform these partnerships, and provide an example of an ongoing research-practice partnership

Interest and learning in informal science learning sites: Differences in experiences with different types of educators.

This study explored topic interest, perceived learning and actual recall of exhibit content in 979 children and adolescents and 1,184 adults who visited informal science learning sites and interacted with an adult or youth educator or just the exhibit itself as part of family visits to the sites. Children in early childhood reported greater topic interest and perceived learning, but actually recalled less content, than participants in middle childhood or adolescence. Youth visitors reported greater interest after interacting with a youth educator than just the exhibit, and perceived that they learn more if they interact with an educator (youth or adult). Participants in middle childhood recall more when they encounter a youth educator. Adult visitors reported greater interest after interaction with a youth educator than with the exhibit alone or an adult educator. They also perceived that they learn more if they interact with an educator (youth or adult) than just the exhibit and perceived that they learned more if they interacted with a youth educator than an adult educator. Results highlight the benefits of educators in informal science learning sites and document the importance of attention to developmental needs

Understanding Parents’ Roles in Children’s Learning and Engagement in Informal Science Learning Sites

Informal science learning sites (ISLS) create opportunities for children to learn about science outside of the classroom. This study analyzed children’s learning behaviors in ISLS using video recordings of family visits to a zoo, children’s museum, or aquarium. Furthermore, parent behaviors, features of the exhibits and the presence of an educator were also examined in relation to children’s behaviors. Participants included 63 children (60.3% female) and 44 parents in 31 family groups. Results showed that parents’ science questions and explanations were positively related to children observing the exhibit. Parents’ science explanations were also negatively related to children’s science explanations. Furthermore, children were more likely to provide science explanations when the exhibit was not interactive. Lastly there were no differences in children’s behaviors based on whether an educator was present at the exhibit. This study provides further evidence that children’s interactions with others and their environment are important for children’s learning behaviors

The Relations and Role of Social Competencies and Belonging with Math and Science Interest and Efficacy for Adolescents in Informal STEM Programs

Abstract: Adolescence represents a developmental period of waning academic motivation, particularly in STEM domains. To combat this, better understanding the factors that might foster STEM motivation and interest is of importance. Social factors like social competencies and feelings of belonging become increasingly important in adolescence. The current study investigated structural relations between social competencies, feelings of belonging to an informal STEM learning program, math and science efficacy and interest in a sample of 268 adolescents (Mage = 15.25; 66.8% girls; 42.5% White British or European American, 25.7% South Asian British or Asian American, 15.7% Afro-Caribbean Black British or African American 5.6% Bi-racial, and 3.0% other). Adolescents were recruited from six different informal learning sites (e.g., science museums, zoos, or aquariums) in the United States (n = 147) and the United Kingdom (n = 121). The results revealed positive relations between social competencies and belonging, and between belonging and math and science efficacy and interest. Further, the results also indicated a positive indirect effect of social competencies on efficacy and interest, via belonging. These findings have implications for guiding informal STEM programming in ways that can enhance STEM motivation and interest