How competition could limit the size of a bird population

What is the role of institutions in society - do they perform positive functions, or simply work in the interests of the powerful and against the powerless? (a related question here is why do our life chances vary by class, gender and ethnicity)

Is it true the ancient egyptians created a calendar that had 10 days in a week

Francisco loves to learn, but his lack of english makes him feel “nervous and scared.” why is he both happy and scared of school