The birthday paradox arises because with N people, there are N^2 possible pairings of people for birthday collisions, and thus the number of people required for

The birthday paradox arises because with N people, there are N^2 possible pairings of people for birthday collisions, and thus the number of people required for a collision scales as sqrt(D), an unexpected result. But here, there aren't N^2 possible pairings since each researcher would still just be studying 1 gene. So this is really as surprising as the article claims.