This is the growth rate-density relationship; it is found in every standard manual of ecology (if you care to read them(; this is taken from here 8a site of physicists, alas!). Mc Gill "discovered" the right half of the graph. Also Thuiller et al 2016 (see below) discoevred the right half of the graph since ihey fitted a linear and anot a quadratic model to their data (and of course they also were suprised)
Ah, palying with computers instead of studying ecology is very dangerous for thinking. And I am angry that I need to be so polemic. Thuiller, et al 2014. Does probability of occurrence relate to population dynamics? Ecography 1155-1166 say the same but with less anger.