Does the ranking position predict the final combat outcome in Senior and Junior judo athletes?

<p>The aim of this study was to identify whether ranking position predicts combat result in Senior and Junior male and female Spanish judo athletes, and how it influences the different stages of the championship. The sample was composed of 683 combats from the Senior (male = 164; female = 158 combats) and Junior (male = 193; female = 168 combats) Spain 2014 Judo National Championships, including all weight categories. Data were obtained from the official classification published by the Spanish Judo Federation. Main results revealed important advantages of high-ranked athletes, finding differences between sexes and championship stages. Specifically, high-ranked athletes had more probability of winning and passing to the next stage. This advantage appears to be greater at the initial phases in females but mitigated as the championship progresses. Interestingly, the quarterfinal appears to be a critical phase in which better skilled and prepared athletes are likely to win. Greater differences between better and lower-ranked were found in Junior females, especially at eliminatory and quarterfinals stages. On the contrary, the Junior male contest appears to be the most equitable competition. These results fuel the debate about the seeding process in judo championships.</p>

The role of male contest competition over mates in speciation

Research on the role of sexual selection in the speciation process largely focuses on the diversifying role of mate choice. In particular, much attention has been drawn to the fact that population divergence in mate choice and in the male traits subject to choice directly can lead to assortative mating. However, male contest competition over mates also constitutes an important mechanism of sexual selection. We review recent empirical studies and argue that sexual selection through male contest competition can affect speciation in ways other than mate choice. For example, biases in aggression towards similar competitors can lead to disruptive and negative frequency-dependent selection on the traits used in contest competition in a similar way as competition for other types of limited resources. Moreover, male contest abilities often trade-off against other abilities such as parasite resistance, protection against predators and general stress tolerance. Populations experiencing different ecological conditions should therefore quickly diverge non-randomly in a number of traits including male contest abilities. In resource based breeding systems, a feedback loop between competitive ability and habitat use may lead to further population divergence. We discuss how population divergence in traits used in male contest competition can lead to the build up of reproductive isolation through a number of different pathways. Our main conclusion is that the role of male contest competition in speciation remains largely scientifically unexplored.