Final answer:
Birth distribution studies indicate that births are approximately uniformly distributed over 52 weeks. Disparities in the distribution of life events are evident across different demographic factors. The question's specific references are unclear in the context given.
Step-by-step explanation:
The main conclusions of birth distribution studies across North America suggest that births are approximately uniformly distributed throughout the year, with the expectancy of a uniform distribution over a spread of 52 weeks. This means there isn't significant variation in the number of births from week to week. Additionally, studies on the distribution of traumatic and other stressful life events reveal disparities when stratifying by factors such as race/ethnicity, gender, socio-economic status (SES), and age.
However, the question's reference to Brown and Mailman in Stevens lacks context and does not appear to align with the provided information, which focuses more on birth distribution, colonization routes, and genetic diversity studies.