The question is, is this meaningful or classifiable. Many other animal species have been around much longer or they have shorter life spans, so they've had many more opportunities to accumulate genetic variants. Penguins, for example, have twice as much genetic diversity as humans. Fruit flies have 10 times as much.
Who wore number 20 for Boston bruins? According to azhockey.com, the number 20 has been worn by 23 different Bruins players. In this decade, Darren Van Impe, Eric Manlow, Martin Lapointe, and Wayne Primeau have all worn 20. Players to wear the jersey in the 1980s-90s were Al Secord, Mike O'Connell, Dwight Foster, Tommy Lehmann, Bob...
Playing football while at U.C.L.A., Robinson wore 28, but for the Bruins basketball team he switched to 18. In his time in the Negro Leagues he played for the Kansas City Monarchs and may have had as many as three different numbers, with various accounts having him wearing 5, 8 and 23. And while there seems to be some debate about his number while playing for the Montreal Royals, the Dodgers Class-AAA affiliate in 1946, a video about his time with the team produced by the CBC clearly shows him wearing 10.