The article discusses an experiment conducted by evolutionary biologist Matthew Zipple and his team at Cornell University, which explores the role of luck and competition in the success of individuals within a population. The researchers released genetically identical mice into semi-natural outdoor enclosures to observe how they develop in a controlled environment where genetics and resources are equal. The study aimed to determine whether inequalities in adulthood arise from competition or random chance. The experiment involved around 100 mice, with groups of 26 two-week-old mice and their mothers placed in enclosures that mimicked natural environments but provided equal access to resources. The researchers tracked the mice over 46 days, focusing on their behavior and fitness, such as weight. The study highlighted the differences in competition between male and female mice, as males compete for territories and food while females do not. The findings suggest that even in controlled environments, micro-contingent experiences, such as winning a fight by chance, can lead to differences in success among individuals.