The last name “Dibaba” will be said numerous times during coverage of track and field.Commentators could be referring to Ethiopian sisters Genzebe and Tirunesh Dibaba. Or they could be referring to marathoner Mare Dibaba (no relation). They could even mention Ejegayehu Dibaba, the older sister of Genzebe and Tirunesh, who won an Olympic silver medal in 2004 but is not competing in Rio.A guide to the Dibabas, the “fastest family on the planet,” according to Vogue:Genzebe Dibaba (1500m)Genzebe, the younger sister of Ejegayehu and Tirunesh, has emerged from the shadow of her sisters. She broke three world indoor records in two weeks in 2014, which helped her win the Laureus World Sportswoman of the Year award. Then she was named the IAAF Athlete of the Year in 2015 after breaking her first outdoor world record (1500m) and winning the 1500m title at Worlds. Tirunesh Dibaba (10,000m)Tirunesh is the most decorated of the Dibaba sisters. She has won three Olympic gold medals and five word championship medals. She is also the 5000m world record holder. She was named Track & Field News’ Track & Field Athlete of the Year in 2008 after sweeping the 5000m and 10,000m at the Beijing Olympics. Her wedding to Sileshi Sihine, an Olympic silver medalist, was nationally televised. They have a son, Nathan.Mare Dibaba (Marathon)Even though Mare is not related to the Dibaba sisters, she considers Tirunesh Dibaba to be her sporting hero. Mare is the defending world champion in the marathon. She became the first Ethiopian woman to win a marathon world championship.Ejegayehu DibabaEjegayehu, the older sister of Genzebe and Tirunesh, won a silver medal in the 10,000m at the 2004 Athens Olympics. She collected bronze medals in both the 5000m and 10,000m at the 2005 World Championships.