The main argument against group selection has always been that, well sure, it would be nice to have a group of cooperators, but as soon as you have a group of cooperators, they're just going to get taken over by free-riders, individuals that are going to exploit the hard work of the others.
O principal argumento contra a seleção de grupo tem sido sempre que seria bom ter um grupo de cooperantes mas, logo que temos um grupo de cooperantes, há parasitas que vão assumir o controlo, indivíduos que vão explorar o trabalho duro dos outros.