Theoretical and empirical studies suggest that the age of first reproduction (the age at which reproduction begins) can have a substantial influence on population dynamics and individual fitness. Using complete survival and reproductive histories of 428 female yellowbellied marmots (Marmota flaviventris) from a 40-year study (1962-2001), we investigated causes and fitness consequences of delaye...

The aim of this study was to evaluate the relationship between age and dental maturity and to establish the standard database of dental maturity based on the Demirjian's stages, which can be used for the age estimation of Korean children. For this purpose, dental maturity was measured by the Demirjian's stages on a randomly selected sample of panoramic radiographs taken from 2706 patients betwe...

Causes of cyclic fluctuations in abundance (population cycles) of some small-mammal populations remain poorly understood despite 6 decades of research and .20 hypotheses. Population cycles are demographic processes and cannot be fully explained without considering demographic mechanisms that underlie cyclic fluctuations in abundance. From simulation studies, we have recently shown that phase-re...

Moral reasoning (MR) is a socio-cognitive skill essential to appropriate social functioning in childhood, and evolves in quality and complexity during ontogenetic development. Past research suggests that MR is related to age, socioeconomic factors, as well as some social and cognitive skills, such as executive functioning (EF), theory of mind (ToM), empathy, and affect recognition. However, the...

This study examined the effects of USDA carcass maturity on sensory properties of LM steaks produced by cattle representing 2 dental age classes. Carcasses identified for use in the experiment were produced by steers and heifers classified as either <30 mo of age (MOA) or ≥30 MOA at the time of slaughter using dentition. Within each dental age class, carcasses were selected to represent 2 matur...