Biology of populations and organisms

The population occupies, in the hierarchy of life, an intermediate level between that of individuals and that of communities. We can define a population as a set of individuals of the same species who share a common habitat (and a community as a set of populations of different species, sharing a common habitat). Under these two apparently simple criteria (conspecificity, cohabitation) lies in fact a vast potential often complex interactions, linked in particular to the needs of reproduction, the inevitability of competition, or even the opportunities for cooperation.The study of populations (dynamics, genetics, age or kinship structures, etc.), in their spatial and temporal dimensions, thus constitutes the best introduction to fundamental mechanisms of ecology and evolution. It is with this in mind that we must approach this course.